3 Remodel Rip-Offs

[@slydog7131]

I installed a solar attic fan. I had collected temperature data via remote thermometers. Installed the fan myself on a west-facing part of the roof (really important) and documented a 10-15 degree reduction in attic temperatures. The house is not air conditioned, and I definitely noticed the inside feeling cooler, probably because of less radiant ceiling heat from a cooler attic. So, for me with a DIY install, it made sense and I'm happy with it.

[@roger51w4]

This guy is so full of _hit and doesn't know what he's talking about when it comes to using to attic roof fans.. Where is the test in the attic to prove this ? My upstairs air conditioner runs so much less during the hot summer after installing the attic roof fan. my walk out attic is 15 degrees cooler and now I can go out there in the day time. What a moron !!

[@fastj1962]

yeah, you want to be sucking the coolest air however, if your entire house is vented, you are sucking cool air from everywhere. I think the atic fans work best in areas other than texas or places with 100f weather because sucking 100f + air into your atic, isn't gonna make a big difference. I live in southern california where its been 75f for the last 3 months straight and its almost July. This week its pretty much 80f. Sucking 80f air into the attic that would be 120f, without the atic fan works well.

[@fastj1962]

I like the poster, and he's pretty smart but even smart people get it wrong sometimes. Like I said, he's partly right in climates that are above 100f. He should have mentioned that.

[@earthangel2524]

@@fastj1962 I live in a small house in So Cal near the ocean too and want to do the same thing before we get a fall heat wave. Our house stays comfortable until about 3:00 in the afternoon. Then, the heat which has accumulated in the attic all day descends down into the house. So I open windows and cool with cross ventilation. But the bedrooms without natural, window cross ventilation get HOT. I want to put the fan directly above the HOT rooms to help them out. I hope this makes sense. May I ask you which fan you bought? Do you have an installer to recommend? I'm on westside of Los Angeles.

[@fastj1962]

@@earthangel2524 There are plenty of ways to get a breeze, do you have a ceiling fan? I have two box fans. I put one at each end of my house and depending on where the sun is, have one pulling air in and one pushing air out. They cost $20. I have them on the windowsill and attach a string to the curtain rod so they don't fall off. I rarely turn on the AC. Sometimes I'll turn it on for a hour or two if the house hasn't cooled off. Its been 80-85 during the day, and 68ish at night. I installed mine but my vent was too small so I have a handyman that helped me install a new one which cost me $70 and I think I paid him $200.

[@missmatt2010]

As an electrician who is always in attics I can say that every time one of those attic fans kicks on it definitely feels cooler in the attic, but I could be wrong.

[@cwitham69]

True that! I lived in attics on the jobs in my earlier trade 40+ years ago.(and visited just last week...) It's a seniority thing. They own the company & you go/do what they say ;`)

[@automobilesarefun409]

It does work. I live on an Island and when elnio hit the Humidity was unbearable. Installed an electric vent and it's definitely cooler.

[@automobilesarefun409]

It depends on your type of roof. How your attic is designed. My house has A Frame. It's Attic height is around 3ft high.

[@heatthermography3902]

Phoenix energy auditor here. The main issue with the attic fans is that they tend to depressurize the attic with reference to the house interior and thus pull conditioned house air into the attic. I use a smoke pen held up at the can lights to show the homeowners that their attic is getting cooler, in part, by pulling air from the house. (The dirty insulation around the can lights further lends credence to this.) We recommend against attic fans for this reason. Also, a properly ventilated attic, with less high vent square footage relative to the soffit vent square footage, is a more efficient way to go. Stack effect will carry the air from the soffit vents to the ridge/dormer vents. At the same time, we recommend proper air-sealing around the house-to-attic penetrations. That said, the fans *can* work, but the house has got to be sealed tight from the attic. “In order for the fan to work the air needs to come from the outside and not be pulled from the house so this means that the attic ceiling needs to be airtight. If the attic ceiling is airtight you don’t need the fan. Your money is better spent on something else.” -- Joe Lstiburek

[@eggnogaddict6287]

You’re probably correct because the attic fan is pulling cold conditioned air from the living space into the attic thanks to the negative pressure effects. This is actually NOT what you want to have happen as now your central A/C is cooling your attic-an unconditioned space.

[@steveloving]

I disagree on the fan. I lived in a townhouse and in the summer our AC would run nonstop and the coolest I could ever get my third floor was 76. Installed a fan that would turn on at 120 in the attic and my third floor would now maintain 70 and the ac stopped running all the time and my electric bill actually decreased. It was the most impactful change I made to that townhouse and the best few hundred bucks I've ever spent.

[@monteglover4133]

I agree in some applications they will save energy on existing homes I am a HVAC professional

[@cyborgdale]

I partially agree with him. I've looked at the solar-powered vent fans and they contain a computer cooling fan!!! My range fan over my stove is more powerful. I'm looking at the AC powered ones but still evaluating. I'm wondering if just installing a powerful range fan or duct booster fan under my current wind turbines will do any good. I'm researching that too.

[@ltcajh]

I have a 1913 church building with zero attic ventilation. With no ridge vent, and no eave vents, my solution, until the next roofing job is to place to electric roof vents, and bore multiple holes in the 2x6 blocking the path to the eaves. Seal off the attic from the rest of the building. Sure, roof venting is needed at the time of the next roofing job.

[@scottstevens2986]

I disagree as well. I had a solar attic vent installed years ago (in Texas) summer electric bill dropped 100.00 per month and it allowed me to get the house much cooler. 100% fact

[@flueflame5438]

Attic fans are terrible because the manufacturer refused to pay for advertising on this channel.

[@nolongeramused8135]

Installing an attic fan immediately dropped the summer temperature in my 2nd floor by about 8 degrees. Also, my energy bill for running the AC dropped at the same time. This is the ONLY PLACE I have EVER heard someone try sell an attic fan as a ripoff.

[@fatjonseatingadventures5429]

This dude has 0 scientific evidence, or examples showing it doesn't work just "trust me man it doesn't work"

[@Doctaphil64]

Attic fans are not a scam and I disagree with the way they were presented in this video. However something I will point out is that most people should not be looking for an easy solution via an attic fan, they should be addressing the actual problems. These include but are not limited to blocked soffets preventing proper airflow to the attic, poor air sealing between the attic and the living space below, lacking insulation, etc. So in that regard I would not suggest an attic fan. I would fix the reason my attic is reaching 150f degrees to begin with.

[@markbeiser]

You should check into what people who actually study building science, and use it to test for and fix problems with homes have to say about powered attic ventilation. None of it is good. In the vast majority of cases, powered attic fans are detrimental to a home to some degree, or at best neutral. When there is an actual perceived benefit, like you claim for your house, it is a band-aid for a home with serious thermal and pressure envelope problems. You would be much better off actually fixing the source of the problems with your home.

[@nolongeramused8135]

@@markbeiser Provide links. I've seen enough people trying to deny basic thermodynamics on this subject to take claims of actual harm to the home based solely on improved ventilation with suspicion. Also, the home is relatively new and completely up to code. Additionally, the entire roof was reinspected for problems when I had it re-shingled. Finally, the anti-fan crowd appears to be an extremely small minority. If attic vent fans were truly harmful to neutral in effect, they wouldn't be so popular and it could be, and would be, easily demonstrated without resorting to moronic claims that moving the hot air out of a mostly enclosed space doesn't cool it off.

[@fatjonseatingadventures5429]

@@Doctaphil64 probably the reason it’s 150f is the god damn sun, so fix the sun?

[@southernhometalk2465]

As a Home Inspector in South Alabama, attic ventilation is a science, where every roof system should be individually evaluated for proper ventilation. Based on the studies I have been doing over the last 3 years, powered attic fans are a better option than just a ridge vent. Matt is correct about about the radiant heat, but powered attic fans will cool down the roof decking quicker after the sun goes down and can reduce the thermal load to framing below the roof decking. They also do a good job of mitigating moisture build up. I also agree with Matt about the potential of pulling indoor air into the attic space. However, I took the time to seal all ceiling fixtures, switch boxes and outlets. The best performing attic systems I have found are properly encapsulated attics.

[@germanicus5066]

You in all the way south Alabama?

[@krzysiekb.3439]

True. Power attic ventilation is great at night. In my house, there is three times faster cooling of attic construction, which gives you great buffor during the day, and much lower temperatures during sunny days. Thermal transfer to level below is reduced or even canceled during some part of the day. It is great solution.

[@ChrisMenge]

THIS!

[@garbizwal]

Hard to cool down when the sun goes down with a solar powered fan.... lol

[@hawksrock3024]

@@garbizwal seriously?

[@BryanTorok]

Looking through the comments, I see that lots of people have had the same empirical experience I had with installing and using an attic fan. I owned a small bungalow which had barely adequate ducting to bring enough warm air to the second floor for heating in the winter and not enough air for cooling in the summer. I installed a gable vent fan and set the remote thermostat to run above 90 degrees Fahrenheit. That knocked the second floor temp down 5 to 15 degrees with the AC temp set the same for the first floor. The fan cost about $50 with about another $50 for the remote thermostat and wiring. It contributed greatly to the comfort of the second floor bedroom. The biggest downside was getting to the fan every couple of years to oil the bearings. Matt, I like your videos. But, you are talking out of your butt on this one. It sounds like a bunch of stuff you were told by people with no actual experience and damages your credibility.

[@ouimetco]

I agree with you. Here in the Okanagan valley very hot summers. Installed a few of these and the customers reported back cooler upstairs on hot days.

[@cyborgdale]

I agree with you. I installed a gable vent fan on a friend's house. The rafters were so hot that you couldn't keep your hand on them. You also couldn't be in the attic for more than about a minute. After install, it was still somewhat uncomfortable but you could touch the wood and could be up there for hours without dying. Of course, the electric bill dropped too.

[@JoeCdaYT]

@@cyborgdale there is a reason us HVAC people if we run into a house that has no ventilation in the attic and equipment is there, we will pull a salvage furnace blower and put it on a gable vent and turn it on for 5 minutes before staying up there for longer periods.

[@HouseORudd]

@@ouimetco Okanagan Valley? Hot summers? ha. Do you understand, this video is from Austin, Texas?

[@ouimetco]

HouseORudd I have been to Phoenix once and ya it was cooking. Hope your staying healthy down there. Lots of horror stories in the media about the pandemic. Cheers man

[@robertmartin8199]

As somebody that lives in Texas and goes into a lot of attics I assure you that I love attic fans when the attic is properly vented. If there are no vents the the fan does not cool the attic.

[@Ifeguy]

yep, same here in Florida. This guy misses the entire point of why attic fans keep the house cooler.

[@azwhitesnake2092]

He is just thinking of what he can say to argue against attic fans. Otherwise he would have actual data and video

[@Rick-tb4so]

Living up north I had 3 ft icles hanging from the gutters and had the home sided with perforated soffit and the icles disappeared.....

[@MrGrigs681]

I have nothing but respect for you and I always enjoy your videos but I could not disagree more on the attic fans. I live in Texas and the attic over my garage would get 140+ until I had an attic vent fan installed. The temperature then would rarely reach above 115 and would cool down to the outside temp within an hour or so after the sun went down. In my experience, they work and they work well. I also should point out that the cooling was NOT because it pulled conditioned air from the house as this attic was shut off from the house and only covered the unconditioned garage. Even more importantly, it made my garage noticeably cooler as the cooler attic radiated less heat down to the garage.

[@JimYeats]

He’s talking about an attic over a conditioned space that uses AC. He is not talking about a non conditioned garage space with an attic over it that’s not in the home envelope. You can do whatever you want there, that isn’t his point.

[@FishFind3000]

jim yeats my sister has one and it works. And it’s over the whole home. Without the attic being at 150° there’s less heat getting into the home. Therefore the home is not getting as hot. It doesn’t suck the ac from the home into the attic. It gets the hot ass air out and replaces it with ambient air from outside. There isn’t enough suction to pull ac from inside the home over the wide open vents all around the eve.

[@VideoShowMeHow]

In Australia here, have them and 100% agree

[@austincohoon4203]

I agree with you. I put one on my house in Texas about 2.5 months ago and I also added about 20" of blow in insulation over what I previously had (30"+ now) so I'm fairly certain my cooled vs uncooled envelope are not interacting as much as they once did. I also maintain a temp and humidity sensor in the attic as well as outside so I know what my conditions are. I never see more than a 20* difference in temp between the attic and outside air. It should be noted that I went for the highest CFM and watt solar fan I could get and where I installed the panel gets direct sun about 85% of the day so it runs constantly when the sun is out.

[@scottfurlong5475]

As a person with a pretty good head on my shoulders, I would have to disagree with Matt on this issue. I say that as long as there is enough makeup air to compensate for the exhausted air, then there is no reason why an attic ventilation fan can't be very effective. You must match exhausted air with an equal amount of intake air. This is ventilation 101

[@TetrahedronIX]

I had a solar fan installed 2 months ago, immediately notice the air in my house seem fresher and my house stays cooler. I use to keep my house at 72 F now I keep it at 75 F because when the thermostat reads 75 F it feels like 72F. My power bill also decreased about 20% but only been 2 months but I'm betting the solar fan is going to pay for itself in about 1 year. Also, I've been doing a lot of work in my attic and it helps out greatly. I also have been told it can extend the life of your roof by reducing damage from the radiating heat in the attic. One of the best decisions I've made.

[@jrod7929]

Can 100% confirm an attic fan SIGNIFICANTLY increased my home HVAC efficiency. First home, builders grade everything, not the most efficient. In South East Georgia home would NOT get below 76° in summer. HVAC just couldn't do it. All I did was cut a hole in roof, installed a wired attic fan. Home was able to get all the way down to 70° during summer if I wanted it to. So obviously the attic fan had a positive effect in my situation.

[@tima.478]

Facing this issue today. Couldn't get below 77/78 inside the house today in Atlanta to save my life. AC working well and doing all it can do. I have to think that if my attic was a bit cooler I could have gotten my temp down inside the house.

[@Doctaphil64]

@@tima.478 Do you have an attic HVAC and how are your soffits* doing?

[@tima.478]

@@Doctaphil64 Unit is in an unfinished basement. soffits vents are about 10 to 15 feet apart, all around the house. The vents themselves are a cluster of about 15 holes, each 3/4" in diameter, covered by a grill. I am actually thinking of removing the grill and making just 1 large cutout under the grill. This might bring in more air than a cluster of holes. I did recently notice that there is a ridge vent that goes across the entire length of the roof. Let me add some backstory: I had the unit turned off on a day that was close to 100 degrees. I was cleaning out the AC coils, fan, compressor area. By the time I got it all cleaned and turned back on it was 78 degrees in the house. The unit simply maintained that temp and was never able to get below that. On a typical day, it has no problem maintaining my usual 72 degrees in the house. My thinking is that a properly functioning unit should be able to achieve whatever temp you set, no matter how hot it is outside. Maybe that's just not always the case, especially in extreme heat. Thoughts???

[@Doctaphil64]

@@tima.478 I live in Texas and I cannot get my upstairs below 77+ any time it is over 100 outside. Using a temperature gun I have measured the temp in my attic at over 156f! In my case the lack of ventilation was the problem. My soffit vents were too small and too few in number. If you do believe the attic is the problem I highly suggest getting one of these $20-$30 infrared temp guns. Get up in the attic when your home is the hottest and measure the surface temperature of your attic floor's insulation. In my case I had too little insulation AND very little airflow to the attic. Additional insulation provided the base thermal barrier I needed. Cutting six new soffits and an attic fan fixed the attic's lack of air circulation. While all of this has been very helpful, it actually has not fixed the situation entirely. Upstairs still cannot cool below 75f when it is over 100 outside. I have a company coming in soon to install a radiant barrier as the final straw. My only other option after that will be to get a bigger unit, heh. Backstory: Two story house in Texas. First floor stays cool, second floor 77+ on hot days. Attic surface temps were reaching 156f before I intervened.

[@riffdex]

Did you install the active attic fan IN ADDITION TO a soffit/ridge vent passive system that already existed? I’m getting my roof replaced in a few weeks and they will install passive soffit/ridge vent system and I was wondering if I should have them install an active fan while they’re replacing the roof, or if the passive system should be enough.

[@rodchesnut7630]

I don’t know what part of the country the writen of this videeo was from, but they did mention Texas. In Texas, every home needs an attic fan or a whole house fan. Period. I moved into a Dallas mcmansion last February. The owner installed Nest hvac controllers cause they are ‘cool” , but he didnt understand hvac nor how to use them. The home was very hot since May. The exterior hvacs had never been cleaned and could not keep up with north texas summer heat. I watched KZbin videos to learn how to clean the outside units & that helped a lot. Then our attic fan died this August. I had just gotten the two Zone - two HVACs & two Nest controllers to work efficiently & our home was much cooler than what we suffered from june-August. When that attic fan died, our home’s temp shot back up like i had accomplished nothing. I pulled the dead fan & we just got the replacement attic fan today . i came back to KZbin to freshen up my install knowledge when i saw this tripe. DO NOT LISTEN tTO THIS FOOL. If your attic fan dies, fix it.

[@billballerini8401]

In Socal we have installed at least a dozen powered, thermostat controlled attic fans in older homes and the owners unanimously agree that it helps keep the house several degrees cooler. All you need to do is grab a chair and touch the ceiling to feel the much cooler surface when the fan is on. Not sure what this guy is talking about.

[@fastj1962]

100% I like this guys videos, however his info in relation to southern california, (Orange county) is just false on the attic fans. Maybe with the solar fans, but growing up in my house I just remodeled, we installed a powered attic fan and it literally took the temps in the house down by 10 degrees. Maybe his info is specific to 100 plus days which we never see. His microwave analogy is bad. OK, the roof is hot. Theres a space between that roof and the ceiling of the house. He's saying that you can't cool off that space with a fan? A microwave oven does not heat up the outside of the oven. Duh. This logic might work on some dude who works in the walmart accounting office but not where I come from. HE says texas a lot in his video, maybe that's the disconnect.. If I were to believe his analogy, then the water cooling system on a cars engine is useless. OK..... next....

[@Detailpops]

How much was it installed ? I’m in murrieta.

[@hawksrock3024]

He's a hack.

[@Linuxhax]

I live in Illinois, attic fans definitely work. Build has this one wrong.

[@phongsolar]

​@@fastj1962Amen brother. South cal attic fan lover here too. It's really a game changer IMO

[@stevosteph1000]

I replaced 36 windows in my house from single to double glass with e c coating. Double hung. My utility bill literally was cut in half. Huge savings. Midwest!!!

[@wonderInNoWhere]

I am thinking the same thing. How much does the 36 windows cost?

[@brianchapin574]

@@wonderInNoWhere Probably a lot more than you will ever save in energy savings

[@miragesmack007]

Not of you repaired your old windows and used a storm, they would be much closer to a new window. Plus, those new windows aren't built for a lifetime, like old windows are. They are rebuldable. Plus, you can now add e coatings to old windows if you like. I rebuilt my windows with new glazing, rope, glass where needed, spring bronze to seal out drafts, and it came to about $37 per double hung window, which should last another 150 years. Add a storm and I have insulated glass, same as new windows. I priced Anderson for my old house, and they were about $39,000. I will die long before those break even.

[@wonderInNoWhere]

@@miragesmack007 Do you have a link for the things you have done? I am thinking about replacing the glass myself. I got several quote, but cheapest one is about $150 for the glass only. Including the labor, at least $300 each for a 34x28 inch glass. It is will expensive than I expected.

[@miragesmack007]

My guess is you replaced old worn out windows. If you restored the old windows, like I always do on old houses, there is little difference. Eventually those replacement windows will live up to their name, they will need replaced. If you had old wood windows, they were rebuildable for the life of the house. But no one maintains windows, they let them go. Single pane is R-1, and double pane is R-2, then other factors increase value somewhat. E coating reflects light, but you can install that on old windows. Then there is gas. My friend who sells windows told me, the only thing he can guarantee, is that the gas is going to leak out eventually. Which gets you back to an R-2 window again.

[@robertmckay7943]

I have a 110 year old house and started off with a very large electric bill. I had two 48x84 windows in the front of my house that were single pane. The front of my house in the winter was at least 10 to 15 degrees colder than the back. I replaced both with double strength IG units. Got an instant difference in comfort. This decreased my electric bill by almost $50 per month. Now I started making more changes in sealing floors replaced both ac units with heat pumps all duct work. Our first winter in this house electric was $750. Per month now it runs about $175.

[@hathawaydj1]

I personally installed an attic fan this summer (thanks youtube) after living here 2 years... helped a whole lot.

[@Bagsn86]

Turn mine on in summer off in winter

[@nystagmus]

Thanks! The whole point is to lower the attic temp to 10 degrees above the ambient temperate

[@Ray96744]

The new ones have thermostats so you don’t even have to turn them on and off. They work amazingly this guy is wrong his science doesn’t even make sense Solar Fan is a great idea

[@phongsolar]

​@Ray96744 Such a claim against solar attic fan not working is ridiculous. I am a big fan of solar attic fan, how can air circulation in your attic is bad compare to none at all. Those whirly birds don't do crap.

[@owenb8297]

I am a Contractor that has used replacement windows since there were replacement windows, And I am here to tell you that they definitely save you energy and cut down on sound. My most extreme experience was in a small condo that only had 4 windows. I replaced all 4 with double pane vinyl windows and their energy bill in the Winter went from $250 a month to $50 a month. Of course most people will not get this extreme benefit. In regards to attic fans, all you have to do is go in the attic in the summer with the attic fan turned off and then turn it on and I guarantee you you will feel a huge difference in temperature.

[@austech360]

I replaced all the windows in my 1200sqft house. They were all single pane aluminum frame. The windows were VERY loose in the frame. They were USELESS.. They were all replaced with dual pane with that silver stuff and argon inside.. I went from running the AC all day. to running the fans at night. The cold air would stay in my house all day long. Saved me OODLES! And yes. Attic fans work.. I run mine for about 3 hours before I have to get into my attic now.. Takes the attic from about 140+ to 80. Helps so much!

[@ward26102]

@@austech360 well now that's a great point. Whether the fan is pulling AC from the house or simply helping push out hot air and replacing it with ambient air, it's a great discussion, but who gives a rip if you have to go into the attic to do things? Attic fan is easier and cheaper than hauling a portable AC up there.

[@taffygeek]

I don't understand double glazing is pretty standard in the UK and most northern European countries. Triple glazing is common in Scandinavian countries.

[@unique3phase]

When I grew up in New York my Dad installed an attic fan and it made a big difference. Much cooler in the house.

[@treeguyable]

Seems logical, not sure what setup he is talking about drawing your cold a/c from your house, must be an attic with sealed off gable ends he is using as a comparison, never seen any of those.

[@jessewilson8676]

I did not know about solar powered vents I live in north eastern Montana winters extremely cold summer extreme hot... well insulated attic no vents during the 16 + hours of sunshine daylight makes it hot it can reach temps over 200°F I cut in two vents (one on each side ). Put a fan in one blowing out. It reduced the temp from +80 to +130 above the outside temp to +20 to +40 above when running regardless if the house AC is running... and when using the AC it runs 2/3rds less. In winter I close up the vents

[@chrisgianettino1079]

I had an attic fan installed, my second floor relative humidity dropped from 70-80% to 45-60%. This is especially helpful since my Mitsubishi H2i doesn’t dehumidify like a traditional AC.

[@sniper524]

Ok well my attic was 142 degrees and now it’s 90. My electric bill went down almost 100 bucks 🤷‍♂️

[@brendapolk1723]

Forget the strange example of using a fan to cool the Hot Pocket in the microwave - it was frozen to begin with and the objective is to cook it! Note than when that microwave is running it uses a powered fan (not convention) to get rid of the hot air being generated by the magnetron. With available gable and/or soffit vents an attic fan helps replace the very hot air from the attic with "cooler" air from outside. Even if you are able to completely seal off and insulate the living space many of the houses here in Texas have the AC fan, evaporator coil, and duct work in the attic. Anything that economically reduces the temperature of the attic air in summer is a good thing.

[@robertatwell7615]

Matt, I don’t think that I can agree with you about the benefits of a powered attic fan. I live in Springfield, Virginia and I have actually measured a 30-35 degree difference in the attic temperature when that powered ventilator is running as opposed to when it is not running. I have had a comprehensive energy analysis done on my home and I know for a fact that my attic ventilation is not sucking air from our second floor into the attic. I have my A/C unit properly sized for my home and not oversized as implied by your video. We have a programmable thermostat but find that we tend to keep our temp relatively constant during the cooling season and normally allow the house to cool off a few degrees during sleep hours in the winter during heating season. We have double pane glass windows with low e coatings. We know that they made a significant difference relative to the old windows that we had when we moved in almost 31 years ago. We bought the double pane windows not just to better insulate but also to improve the looks and reduce the amount of exterior noise infiltration that was something that you did not discuss in your video. I guess my take away from your video is that you see a lot of homes with oversized A/C or heat pumps, you don’t think that a 30-35 degree drop in attic temperature makes a difference, and that sound deadening is not one of the reasons that people replace their windows. I am not certain what to make from your video. For me the attic ventilation temp difference of 145 to 110 is significant. I don’t know if you think that is significant but for us it certainly makes a difference in comfort for us. PS Over the thirty years in our home I have replaced the attic fan motor twice. The total cost of those motors was less than 100 dollars over those 30 years. During one season when we didn’t have the ventilation fan running we had a roughly $45-$50 per month increase in our electric bill. (The bill went from $190 to approximately $240 per month). From an energy perspective I guess that is not a lot of money but from a comfort perspective and level of A/C required it seems like a good return in the long run.

[@NeverEnoughPyro40]

I would have to agree with you! He is pointing out worst case scenarios, oversized air conditioners oversize ventilation fans or lack of soffit vents! My parents live in New Jersey and last year their attic fan stopped working! So I replaced the fan and also replaced theThermostat due to its age! A few years ago I installed a four channel weather station that measures indoor temperature, outdoor temperature, garage temperature and Attic temperature! I just got off the phone with my dad to ask him how hot the attic was when the fan broke, because he watches those temperatures all day long! (Being retired he’s kind of bored) He said on a 95°F day the attic was about 135 to 140°F and with the fan it is about 110 to 115°F! As long as you have enough soffit ventilation or you do not install a fan that is way too big for your attic you will have no issues and it will cool the attic significantly! As for windows I purchased a home five years ago in South Carolina that had single pane windows! So I replaced all the windows and insulated properly around them! I can Positively say when the old windows were in my air conditioner used to run much longer and come on twice as much! The air conditioner stays on about half as long and remains off twice as long! Now my electric bill is a lot lower all year long! The money I spent replacing my windows I got back on what I am now saving on my electric! Anybody can sound convincing in a video by themselves without anybody to argue the other side! Oh and by the way that attic fan I just installed is only the third fan since 1984! There are a lot of nice homes and cool ideas in his videos but sometimes he can really talk out of his ass!

[@matthewmiller6068]

I have seen 30-40 degrees difference in Spotsylvania/King George VA with a wireless thermometer in the attic and powered fan. Much hotter now that the motors burnt out and got disconnected (and the landlord won't replace them)

[@jaydee6268]

Matt how much did it cost and how did you manage your comprehensive energy analysis? Did Dominion help in the cost at all?

[@ronirby4496]

I live in Virginia also (Hampton Roads area). This is our second summer in this house, and the first summer with a powered attic fan. Our electric bills this summer have been $60-$80/month lower than the same time last year.

[@squidusn71]

@@ronirby4496 what fan did you get? Im considering putting one myself.

[@fairweatherfoundry715]

First off, the sun heats the roof shingles by radiation, the roof shingles heat the roof sheathing by conduction, and the roof sheathing heats the attic air by convection. By bringing in cooler air, you are cooling by convection and it WILL make a difference because the air is being heated by convection. As others have said, I think this works better with one fan as an intake, and another an an exhaust to keep the pressure balanced. Second, the airwave and fan on a smart thermostat do not really cause moisture to raise substantially in my experience. I live in a single story ranch which I put AC in after I moved into it. I run the fan every 30 minutes because it circulates and filters the air in my old house. I also have airwave on and I am looking at a humidity sensor that says 39%. This is after a very hot and humid June day. The reality is, the system removes so much moisture (and drains it) when it runs. This added moisture back in does not appear to be problematic at all. At least for me. The window thing makes sense to me.

[@vennic]

The roof deck will still also radiate heat into the attic. Stand in an unfinished garage on a hot day and then hold an umbrella over your head, you can feel it

[@boxsterman77]

Radiant energy can penetrate surfaces that appear opaque to our limited range of visual sensing. So, yes, some radiant heat blithely passes through the shingles and is not IMMEDIATELY converted to conductive at the roof surface level (not everyone has shingles) thence convective thermal energy. kzbin.info/www/bejne/gpWboa1_qplofJo

[@boxsterman77]

@@vennic Thank you. Much radiant energy is converted into conductive thermal energy thence convective energy, but not all. Just because a surface appears opaque from the standpoint of our limited rage of radiation perception (aka vision) doesn't mean that some radiation blithely passes through it.

[@alumniduck]

If the eave vents are not plugged air will freely move back to the attic and the "negative pressure" is inconsequential.

[@dcviper985]

If your ceiling isn't air tight you can potentially pull conditioned air from below into the attic. I totally agree on airwave and fan scheduling. My upper floor is 3-4 degrees warmer without it.

[@jakeraine2386]

This video was a rare swing and a miss from you Mr. Risinger.

[@Ifeguy]

He completely misunderstands why moving air through the attic keeps the house from heating up.

[@justbecause9645]

He comes off like a dick.

[@calholli]

I honestly think he made this on purpose.. just to stir people up and get everyone talking in the comments.. and feed the algorithm

[@Jackson-T23]

Update on our solar attic fans. Heat advisory today in North Texas with temperatures at about 100. I just checked, and out two 30 watt solar attic fans are spinning like jet engines. The thermometer in the attic says 103. Seems to be working great.

[@eggnogaddict6287]

That’s because cold conditioned air is being pulled from your living space into your attic thanks to the negative pressure from these fans. It’s not solving the underlying problem, but “tricking” you into thinking it is because the attic is cooler. The attic is cooler because your house’s AC is now supplying cold air to your attic as air leaks are pulling that cold air into the attic at a higher rate with that negative vacuum pressure from the attic fan.

[@Jackson-T23]

@@eggnogaddict6287 I simply don't believe that's true. There's no way those two fans create enough negative pressure to suck air (through 18" of blown insulation) from inside the house. These are not commercial floor drum fans. They move about the same amount of air as a desk fan. If anything, they will pull in air from the perforated soffits around the perimeter of the house. Now if we had a unit pulling 20,000 cfm and huge holes in our ceiling then the situation would be different. Anyways, the benefits of having an attic that is slightly above outside temperatures and not 160 degrees cannot be overstated. You don't have that lingering thermal mass overhead, and you save a lot more energy because the HVAC system doesn't have to cool the ductwork before cooling your house.

[@eggnogaddict6287]

@@Jackson-T23 I mean, you can believe whatever you want, and it seems like you’re defensive because this is your current setup you spent real money on, and the thought of it being incorrect means not only did you waste money to not solve the problem, but if you are wrong then that means you have to eliminate your attic fans and spend thousands more to do it correctly. There are reasons why roofers don’t combine multiple exhaust methods for a roof. For instance-a ridge vent with gables, or a ridge with a passive wind turbine. The effects are detrimental to air flow within your attic resulting in a humid attic risking mold. Likewise, adding a powered exhaust with passive intake is a terrible idea. You want the intake to exceed the exhaust for the very reason of the negative pressurization you create. With undersized intake, your exhaust “sucks” air from wherever it can find it. That means from within your conditioned living space. 18 inches of blown-in insulation is not an air seal. Insulation is a barrier to conductive heat transfer, not air leakage. You stop air leakage by air sealing gaps with foam spray or caulking. A layer of batt insulation or 10 feet of blown insulation is not an air seal. The air loss moves through the insulation fibers. Do yourself a favor and scoop up a handful of insulation and tell yourself that stops air leaks. Then, caulk or spray foam a gap and see if any air flows through it. Done correctly, it won’t. Cover the gap with blown in fiberglass and blow lightly on it. The fiberglass will move and allow air through. You don’t solve air leaks by adding more insulation. You move the insulation out of the way to caulk/foam the gap. So yes, attic fans do create a “suction” effect pulling conditioned air from the living space whether you want to believe it or not. All laboratory research points to this fact. The DOE recommends against attic fans for this very reason. You just seem incredulous that a small fan could do this. Have you ever blower door tested your house? One fan in your doorway finds leaks through the entire house. I just blower door tested mine and found leaks in my basement from a fan on the floor above me on the other side of the house. So yes, fans do more than you think or “believe”

[@Jackson-T23]

@@eggnogaddict6287 Yes, and I will still continue to argue attic fans do much more good than harm. I've yet to hear anyone say their electric bill has gone up after adding attic fans. Have you? But there are scores of people who have had their energy usage go down....just read the comments. If these fans were pulling mass amounts of cool air into the attic, their e-bill should skyrocket should it not since they are essentially adding a lot of square footage their AC needs to cool. It would be analagous to opening the door between your house and garage and blowing cold air into it. Your electric bill would go way up. BTW the primary function of attic insulation is not to stop conductive heat transfer. It is to stop convective heat transfer by retarding the movement of air. The batts or blown insulation have millions of tiny air pockets that essentially stop air movement. So the hot air stays on one side and the cool air stays on the other. So to say that mass amounts of air is leaking from inside the house, through R60 insulation, and out the attic fan is a stretch IMO. As many others have already stated, the air movement in the attic will follow the path of least resistance (just like your blower test). When the attic fans pull air out, the majority of the air replacing it isn't coming from the house. In our home, it's coming in from the 75+ feet of perforated soffit vents around the house. Anyways, I have absolutely no regrets or remorse buying those attic fans. If I did not currently have them installed on my house. I would gladly spend the money and have them installed today even after reading all the pros and cons. Our attic temperature is just above outside temperatures during the summer and gets pretty hot here in Texas. 2 story house is 4100 sq. ft with 25 ft cathedral ceiling and a total of 52 windows throughout so it's no cakewalk in term of energy conservation . Our e-bill is under $200 per month in the summer with thermostats set at 76 @ $0.13 per KWh.

[@eggnogaddict6287]

@@Jackson-T23 absolutely ridiculous. You air seal the attic floor and then add insulation. The insulation is not an air sealer and conditioned air moves through attic insulation when the attic floor is not properly air sealed. Adding more insulation does not change nor solve this. From the sounds of it, you must stuff batts into the rim joists, too, huh? Do yourself a favor and read up on batt insulation in the rim joist and how that design actually results in a rotted rim joist. How, do you ask?! Because the insulation with “millions of air pockets” allows humid air THROUGH the insulation, touching a cold wooden rim joist in the wintertime. The result is condensation as humid warm indoor air moves THROUGH the insulation and condenses. The solution is to air seal the rim joist and add rigid foam board. Batt insulation is an absolute worst practice precisely because air passes through it, trapping moist air that condenses and rots the wood. Same principle applies. Air isn’t “trapped” by loose blown in insulation. As I said, pick up a handful of insulation sometime and blow on it. Let me know if it traps air, would yah?

[@thedavidfrank]

Matt, in my case in Seattle it was a huge game changer for us. Mind you, we have a massive vent on the other side of our attic, so we didn't have the pressure issue you mention. It reduced the temperature significantly in the attic, and meant that we don't need to turn the AC on at night. I have since fitted a smart switch to it, and put a sensor for my smart thermostat up there, so I can gather hard data. Next summer I'll test it and send you the results if you're interested. Just reply to this message.

[@jonnykromps9836]

Don’t forget the main purpose of a powered attic vent fan is to exhaust the humidity first, then heat second. Humidity will lead to mildew buildup, then eventually mold. And with certain types of roof styles (ie hip roofs) there isn’t enough balance of ridge venting along with soffit venting to adequately vent both the heat and humidity. Power venting the attic is almost never a bad thing to have

[@EODrunner]

That's the main reason why I put in an attic fan. Reducing the humidity in the attic has helped a ton.

[@sprockkets]

You guy are a riot. THINK: How does taking in humid air from outside reduce humidity in your attic? It doesn't! This is a classic blunder and misunderstanding of what "relative" humidity is.

[@michaelbagwell3485]

@@sprockkets Go study the relationship of grains of moisture in air to the air temperature and you may understand how moving 95* air in Georgia through a hip roof attic will reduce the relative humidity of the attic air and reduce the temperature of the sheetrock ceiling in the afternoon and evening making the energy costs of a properly maintained A/C system less than it would be otherwise.

[@eggnogaddict6287]

Don’t forget power venting your attic pulls cold conditioned air from your living spaces, so now you have more load on your HVAC systems to cool an area of the house you shouldn’t be cooling. Far better solution is for soffit/edge vents with adequate exhaust in the form of a ridge vent or turbine.

[@rhondaburrell3267]

So far, so good! I installed this fan yesterday. kzbin.infoUgkx7yWIKcrbA9KMHkGSfcgxW2lsjHT6B8Sh I've been watching a continuous radon monitor in my house for about a week, and the levels have been running between 4.5 and 7.9 pCi/L. Shortly after I installed this fan, the radon level started dropping, and in less than 24 hours since I installed it, the level is now 1.9. My basement is approximately 2,000 square feet. Total home square footage above basement is approximately 4,000 square feet. The noise level so far is very quiet. Mine is installed indoors, so I had to purchase a cord and connector. If I have any problems later, I'll update my review. But for now, I'm very pleased with it.Update after 48 hours: Using a constant monitor, my radon is now fluctuating between 0.38 and 0.45 pCi/L. I've moved the monitor to my basement and am getting a constant 0.43 reading. After 24 hours, and when I know the weather will be safe, I'll place the monitor outside for about 12 hours. I'm thinking that the 0.38 to 0.45 may be the outside "ambient" radon level. I'm using this monitor (purchased from Amazon): Corentium Home Radon Detector by Airthings 223

[@danb.709]

I'm really sceptical about the attic fan thing, that's like saying that rolling down your car windows in the summer won't help cool your car down.

[@scottbitz5222]

3 differences: 1) Static attic vents (industry standard) will let hot air out and pull cool air in just by the natural pressure differential between the free, cooler outside air and the hot attic air. This cooler air comes in through the soffits underneath your roof and the hottest air will flow out the rooftop vent especially with most roofs having ridge vents now which is perfectly at the hottest part of the roof and so that air escapes the easiest. 2) You're cooling your house as well and the pressure differential could pull air from your house into your attic if the pressure is different like what he said in the video. 3) Your house doesn't move. Basically, a house is more akin to a parked car and a static roof vent is like cracking your windows, however, it would also need an air vent at the base of the car door to let cooler air into the car and the hottest air out through the cracked window.

[@MarlowWhere]

No that thats like opening your windows and then putting a tiny computer fan in the window to pull more warm air out and saying you notice a difference. That fan is not capable of generating the air flow required to cool you or the car.

[@notsure7874]

Or it's like saying cooking with the oven door open is just as efficient as with it closed.

[@ryckXattack]

Well, houses don't move, so you can only compare them to a parked car. So what you just described is passive ventilation, which is what he promotes. It's actually like saying installing a roof fan in your car will cool it down if you insulate and air condition under the car. Then the fan can pull the air conditioned air air up into the car like it does with houses. If all you care about is the attic being cool, just skip a step and run ducting up to the attic from your AC, the efficiency will be similar.

[@notsure7874]

@@ryckXattack Also - you're not pulling very much conditioned air from the house - that's what soffit vents are for. Putting an attic fan is the equivalent of instead of sitting in a hot car with windows down - driving it, AKA forced air. And another point - you talk about air conditioning the attic? Insulating the rafters makes the attic conditioned space, so that's EXACTLY what you're doing when you spray foam rafters - you're air conditioning the attic.

[@JeffreyKelley]

So, I have an attic fan and a smart thermostat. You are cherry picking arguments against them. I'll start with smart thermostats. Most energy companies give a rebate on them so if you get one on sale you can get like a nest for $200 or even the E version(lower end) for $100 sometimes. My power company gave a $75 bill credit and it allowed me to enroll into the program where the power is limited on heavy use times but I can override that very easily if it happens. It happened for me like 5 times last year but it gave me a $40 credit on every bill that it happened. That with the added ability to customize the settings is well worth it. also if its a particularly hot day I can go on my phone and put the AC lower while im not home so my pets are more comfortable and so its nice when I get home. As for attic fans...I have 2 types. I have a whole house fan that we use in the mornings most mornings that sucks in a ton of air from outside and pushes it into the attic and one of those solar ones. My attic isn't air tight. I don't think any are in my area. It has vents to the outside so when its 100 degrees outside and that solar attic fan is going its removing super hot air and replacing it with just the normal hot outside air. After we got the solar fan we noticed our bill on average in the summer dropped about $20. We were using less AC. We have only had it for a few years and it's paid for itself. Our smart thermostat is also paid for itself and more really.

[@steve-o-9000]

I got my Nest E on sale and it cost me less than $10 after rebates. Definitely worth it. Plus, the airwave function of the Nest only comes on if the humidity is low! So if you're in the west or somewhere else with lower humidity, you can take advantage of the cold left in the coils to do more cooling instead of just wasting it! I also use the fan setting because I have a basement with cool air that I can pull from and circulate around my house, providing cooling without having to run the AC compressor.

[@DanMcD80]

You have to remember the duct insulation isnt super thick so with arid stagnant temps in the attic that heat is going to heat the air in the ducting too so with a positive discharging system for that heat you should see lower bills as the cooling system doesnt have to work as hard to cool the air going into the conditioned space. In theory I can agree with Matt that a single deck vent by itself (during the day) isnt going to be able to make a dent in the attic temps. Add an intake fan thou which creates circulation and I disagree in them being a waste.

[@Nicholas-f5]

Same here 👏🏽👏🏽👏🏽

[@kennethmc2601]

Yea I am going to have to agree on the thermostat points. There's also the convenience factor. Wake up in the morning, walk into the hallway, thermostat greets me with the outdoor temp, weather, and temps for the day. I deploy a lot, it's nice to check on that whenever. Back when I was troubleshooting a bad condenser fan, it was really nice to not have to go in and out of the house 37 times, because I can just run it from my phone. Plus it just looks great. Say you are selling your house, what do you think is going to impress a potential buyer more, a faded beige box on the wall or a stainless steel ring with an LCD screen?

[@toddac61]

NYG&E had the Sensi for free (pay shipping and tax) so I got one. Liked it and next year they had another rebate where it was $25 so I got a second one for upstairs.

[@Padoinky]

This is very on point, concise and informative. I live in DFW, have a 6,000sq ft home (6k sqft under roof/ under HVAC coverage) that was built in 2000. I just got done putting in: 4 complete HVAC systems, replaced 3-50gallon water heaters with two instant-on AO Smith tankless water heating systems, replace 28 operating windows, with double pane Jeld Wen windows, changing some of the windows to non-operating models, had all windows and doors, weather striped and otherwise sealed, replaced the 20y/o roof and replaced the 2 double garage doors (aluminum) with insulated fiberglass doors, new molding and weather striping, new tracks and new openers. Also replaced all 5 pool, spa, waterfall, water jets and pool cleaner pumps and had pool tile, grout and couping renovated... already have a whole house NG backup generator but now having replaced the roof, am looking to install a solar system... it seems that here in North Texas, HOAs can not prohibit the installation of residential solar systems... maybe you already have created a solar power how-to video?

[@josephklimchock5412]

I installed an roof mounted attic fan and gable one also the other side of the house over 30 years ago and It reduced my power bill over 75 bucks a month In the summer here in Florida. I can feel the pull of outside air entering at the eve vents, and it then gets pulled thru the attic, along with the hot air already in the attic, so this video can claim what they want, I know that mine works for sure.

[@mrjowjoe]

I loved getting double glazed windows, mainly for the sound insulation! Made road and train line sound almost silent in the house!

[@jblyon2]

I stayed in a Manhattan hotel once with single pane windows. Good lord was it loud. Might as well have left them open!

[@gorak9000]

Heh, double glazed windows, how quaint. In the parries in Canada, the better homes have triple pane windows! Need it to keep the cold out in the winter, and the heat in the summer! My parents replaced the double pane windows with triple pane shortly after they bought the house. I always wondered why being in almost any other house always felt colder and draftier.

[@Perly53]

@@jblyon2 Same thing for me in a San Francisco hotel.

[@openyoureyes3113]

You should try some triple Glazed windows 🤷‍♂️

[@johnrobinson4445]

"separate dehumidifier" Best. Advice. Ever. Our bodies are great at cooling us naturally, if the humidity is low enough. Buying a small dehumidifier is the best 150 bucks I ever spent. Yes, it has a *slight* warming effect (maybe a degree after several hours) but that is only felt in the immediate vicinity of the dehumidifier and is easily knocked down by 5 minutes of air-conditioner. It's wonderful to wake up to a dry living space on a humid summer day.

[@SeanBaker]

I've considered going to a big box stores and getting one for my bedroom. It can be SO uncomfortable during the summer nights and mornings.

[@maciejrudolf]

I'm pretty sure what Matt had in mind is a central dehumidifier (based on his previous videos) which will run you a lot more than $150 and not worth it in my opinion. Your A/C should dehumidify just fine. But your suggestion is much more viable.

[@elihappinesspie]

150% agree! I just got a little freestanding dehumidifier - nothing fancy like what Matt has shown in previous vids - and that thing has made a WORLD of difference! In my next build, I will definitely install a full-blown dehumidifier system - non-negotiable. I will never be without one again.

[@kevinbarry71]

Generally I agree about the attic fan; however, I installed a gable end fan in an uninsulated garage. Made an enormous difference in the summer. Before it was incredibly hot. Afterwards it was the same as outside temperature. Of course it was easy for the fan to pull air in from the bottom. Which is what I wanted

[@carlospelay9642]

I've been thinking of installing one too. Dumb question do you have to leave the garage door open slightly or install vents anywhere to bring in air from the outside?

[@namAehT]

If your conditioned space is sealed from your attic (and the only place it can pull fresh air is from the soffits) it'll work as intended. If the whole area is unconditioned then it'll work as well. The only time you'll run into a problem is if you don't have soffit vents or if you don't have any sealing between your conditioned space and your attic. It's just a more aggressive version of the ridge ventilation most roofs already have.

[@Kistilan]

Yeah, I did the same in my attic (insulation on bottom, nothing on roof) and it improved the air quality and temperature substantially.

[@gisk7846]

You are right. powered ventilation systems are helpful to speed up the time of cooling in the night. Think of fans to control heat in desktop computer cases.

[@bobp1016]

We have one too and it made a difference in our cooling bill. It makes the biggest difference at night. Gets rid of the hot air and plus in the cooler air. Our house has vents in the attic so it does not pull any air from the house.

[@eliznaomistuart]

Thank you for this video! I found all of the positive comments about attic fans so helpful and they convinced me to install one!

[@stephenkeebler732]

My parents 60 year old house in Central California used to have ceilings that were hot to the touch in Spring and Summer, a few of the rooms were like sweat boxes by the end of the day. I installed a thermostatically controlled Solar Roof Vent, a nice one, with a real fan in it. I also adjusted the angle of the Solar Panel to get more Sun during the hot part of the year so it would pull more air in Summer, much less in Winter. It dropped their Aircon usage significantly, ceilings were barely warm in Summer, warmer in Winter. A win/win in comfort, paid itself back easily the first year...

[@danielfinnsson1985]

Love the channel and watch a lot of your stuff. In this instance as far as the thermostat and the attic fan I would disagree. I am an HVAC tech. A lot of two story houses have attic furnace/AC units here in Idaho. Solar attic fans at least in this climate is worth the investment. When I get into the attics in a hot day 80 plus they can be 160 degrees or more in the attics. If there is a solar fan those attics are closer to 90 to 100 degrees. When the attic is that hot if there is any duckwork in the attic that heat will transfer into the ductwork. That will lower the temperature comming out of the supply vents by at least 10 degrees and thats insulated ductwork. The solar fan helps reduce the amount of time the AC has to run to keep set temperature. On the issue with the fan being on after AC use the amount of water that is returned as humidity is a small amount. I always tell clients with two story homes to either run the fan on continuously or on circulation node if they have a smart thermostat. It has a more even temperature throughout the house amd less time will be needed for the AC to run. An ECM blower motor is best for that because it will have reduced fan speed for continuous use but normal speed for when AC/furnace is running. Again love the channel but disagree on those two points. Though I will concede that your points are valid in some climates and some houses depending on the attic set up. Some attics actually have air intakes and some dont.

[@davidweggel9573]

Wow a lot of disagreeing

[@PianoUniverse]

@@davidweggel9573 And rightly so.

[@hawksrock3024]

@@PianoUniverse Exactly 💯

[@mtsaz100]

agree 100%. I am in Az and its 110 outside, attics are 140 if properly ventilated. If not- they are pushing 200. He needs to stay in his lane---and stick with building and not try to be an expert in everything.

[@klundin]

Sorry this one is a miss for me. Presuming that the attic vent negatively pressures the house would have to assume that there is zero soffit or other means of attic fresh air intake. I also believe the illustration is showing a total sealed standard every day attic vs a vented attic whether power vented or not will be cooler. Well vented attics are cooler than poorly vented in hot climates which I believe can be called a fact?

[@tmiranda1379]

Karl Lundin you are correct. In a hot and dry climate the more attic venting the better. Otherwise your attic will be 160F in the summer and your 40 year comp roof will only last 20 years.

[@jasonvillamil2046]

Agreed. I did my own installation of a wired attic fan a few years ago, and measured a before and after attic temp drop from 160 to around 120 during the heat of southern summer. The attic was designed with ridge vents and soffit vents, and the fan addition dramatically helped the HVAC system keep the house cooler. Was one of the best $120 I ever spent.

[@zefrum3]

Karl you are incorrect, no presumption is being made. All fans have a negative pressure and positive pressure fronts, doesn’t matter if the fan is installed on a sealed container with only opening is at the fan; it will depressurize the container.

[@zefrum3]

Jason Villamil well thats weird, my house came with one and doesnt help the house or even just the attic cool off.

[@danwilson6885]

Added a Solar attic fan...20 year old house...ran air during the day, not at night. But upstairs still warmer and uncomfortable. With the solar fan, it kept the upstairs cooler. Instead of 2 floor fans and 1 ceiling fan at night in the bedroom, now we just need the ceiling fan. Best $300 investment I ever made.

[@jasonlessard2373]

I changed my Windows from single pain aluminum to double pain vinyl. I live in NW Washington state. The house is 50 years old, the Windows were drafty and the thermal transfer of the aluminum frames was incredible. Touching them on a freezing day or hot sunny day sold me on new Windows.

[@GeoRedtick]

Before I replaced my double pain aluminum windows there would be days in the winter where ice would build up on the inside of the window frame.

[@machawley]

Matt, I love your experience and thoughtful advice on home remodels. My comment is on a slightly different fan. I live in Denver, CO which has very high heat gain during the summer months and typically dry cool nights. Several years ago I installed a whole house fan that takes air from my 2nd story and blows it into the attic. The air exits through roof Turtle vents and a longish strip vent. If I have a nightly low temp below 70f, I can open doors and windows and start blowing as soon as the ambient temp falls below 80f. By morning, my whole house is in the 68-72f range. Over the last 4 summers, I've used my A/C approximately 40 minutes per summer. My electric bills average around $60. My neighbor with a home footprint the same as mine that was built at the same time by the same contractor averages about $500/month. So in my case, the whole house fan paid for itself in 3 months and has been saving my a lot of money ever since.

[@Mike_Ruggeri]

As a roofer... who also installed a solar attic fan on my own home... they most definitely work and are most definitely not a scam.

[@ksoman953]

Good stuff. The one item I'd defer with is replacement windows. Back in 2004, I bought a real old house and was paying $600/mo or more a month during winter in heating. Replaced the windows, and my heating costs dropped to about $300/mo. Take 4 months of cooling, average about $1,000 of saving + $1,000 in comfort a year, I paid my new windows in about 6 years. Stayed in the house longer than 10 years, money paid back. If for no other reason, the comfort alone really made the difference considering the old windows were basically sieves.

[@Susan70003]

And then the seal breaks and the windows fog up and water etched the glass. New window time. I am keeping single pane and getting storm windows.

[@enottelling2359]

Replaced the windows in both of my renovations and it was an immediate difference. the old windows on one were so leaky you could put a paper in front of them and they would blow with the wind. Plus it would be so cold upstairs. We replaced the windows and now the upstairs holds the temperature so well furnace doesn't turn on for hours. Plus its nice to actually be able to see outside.

[@nateb7354]

I really appreciate this video. The difference between Texas and New York really is aggressive. I personally am saving over $150 per month seven months of the year during the winter time because of my new windows. It will take me about seven years for the windows to pay for themselves. If you factor the increase in value of the home it takes about 2 1/2 years for the windows to pay for themselves.

[@IceAgeSquirrel2008]

As a test, I put a box fan in my attic. On the lowest setting, I aimed the fan toward the gable vent. All I wanted to do was create movement of the air not a suction or vacuum. I monitored the temperature constantly via an inexpensive indoor WIFI camera and a thermometer. On a warm day I was able to reduce the temperature considerably in the attic. I did not want to manipulate the pressure in the attic, I only wanted to gently move the air around. I just wanted to create a small current of air and encourage it to move. It worked for me. I also connected the fan to a WEMO receptacle so I could schedule it to turn on and off whenever I wanted it to. The WIFI camera is infrared so I could monitor the thermometer in the dark attic.

[@owenf4535]

You know you can get a cheap wifi or Bluetooth thermometer so that you can do this without a camera. Keeps detailed historical readings for you as well.

[@IceAgeSquirrel2008]

@@owenf4535 I was sure that I had checked this out and that I was disappointed. Your reply made me look again and you are right, there are some inexpensive Wi-Fi items out there. Thanks!

[@CaptainCrunch823]

Matt - thanks for the comment about the “Airwave” setting on Nest thermostats. We love our Nest thermostats but were having humidity issues downstairs but not upstairs. Never would have figured out that we had Airwave turned on downstairs but not upstairs without your video. Thank you!

[@Furiends]

Regarding Matts last point don't get the wrong idea. You should still purchase double or triple pane on new construction since you'll pay for the install labor either way.

[@lynxdiamond4888]

He's talking about remodel rip offs though

[@DanielRichards644]

pretty sure you can't buy new single pane anymore.

[@ericgustin3386]

@@lynxdiamond4888 how is upgrading your windows from single pane to double pane insulate a ripoff? this guy is absolutely wrong about every "scam" he made his video on.

[@AnthonyBrusca]

@@ericgustin3386 You obviously didn't watch. He said on a remodel, the payoff is a lifetime if your goal is energy savings.

[@MarlowWhere]

@@ericgustin3386 have you ever priced out new windows for a whole house? You'd have to be in your house minimum 20-30 years to justify the expense. They also at best improve the value of your house to the tune of maybe 70% of the cost. So if you are putting in new windows to sell in a couple years, you are again losing money. Your money would be much better spent adding insulation to an attic, upgrading an old hvac system, new water heater...

[@tmiranda1379]

Bummer, incorrect and completely inaccurate information regarding attic fans. At least in a dry and hot climate. The more attic ventilation the better. It will extent the life of your roof and WILL decrease your attic temperature. In this case, do NOT take Matt’s advice regarding attic fans.

[@sprockkets]

Incorrect. It's bad in any climate.

[@wsattler]

His point is powered attic fans are a rip off. Didn't talk about regular attic vents which obviously are important.

[@sprockkets]

@@shootthechit I'm sorry, did the algorithm wade you and other losers to a video from over a year ago? Tough sht.

[@sprockkets]

@@shootthechit see if IGAF

[@davidmorrow4195]

I used to live in a house that had a powered fan at the end, with far more inlets than outlets I wasn't pulling air out of the house and you could definitely tell the attic was cooler when it was running. Can't see how keeping the heat in the attic would help the situation. When the sun went down the attic went quickly to the outside 80 degrees from the 140 it was when the sun was up.

[@ryanroberts1104]

@@MAGAMAN I totally agree. There is a small argument to be had if you have A/C. If you don't have A/C, you NEED an attic fan!

[@JohnMeissen]

I think there's a difference between a "powered vent fan" and a gable vent fan. The powered vent that Matt showed replaces a typical roof vent, which is near the top of the roof. What happens is that as it pulls air out, the replacement air is coming in through the closest roof vents. So you end up with a circulation near the peak that just goes from one vent to the other, and really doesn't cool the attic space. A gable vent fan, on the other hand, pulls air across the attic. It may still pull in through the roof vents, but it's still evacuating more of the space, not just the small area near the peak. I have a gable vent fan in my 40's house,) which could definitely use more insulation...), and I can tell the difference in the living space.

[@davidmorrow4195]

@@JohnMeissen Many houses don't have roof vents and he didn't say powered vent fans were rip off "if x" only rip off If you have plenty of roof and sofit vents then you don't need any additional venting.

[@ryanroberts1104]

@@davidmorrow4195 The only houses that don't have roof vents were either built improperly, or it is a sealed conditioned space. To say "many houses don't have roof vents" is absurdly stupid.

[@davidmorrow4195]

@@ryanroberts1104 I lived in a house that had only had gable vents. When house was built in the 1920's this is what they did. My current house and all of the houses in my neighborhood (1910's) were built without roof vents, also what they did then. Many of them were retrofitted later but the 3rd floor is a living space with a small/medium sized area in the peak that isn't vented. You're ignorance of how houses were built in the past is absurdly stupid.

[@HomePerformance]

Matt, keep it up. A lot of your viewers don’t have any background info, even they probably listen to you a lot. When you’re pissing people off, you might be onto something. Also, I bet $100 at least hapf of your trolls on this are freaked out because they just installed an attic fan for a client, or for their family. You’re right on science-wise.

[@commonsense5105]

Home Performance, gonna' have to disagree with you. What many are saying is actually accurate. Assuming you have a reasonably sealed home envelope and marginal to adequate ceiling insulation value, combined with a decent attic ventilation, increasing attic ventilation can help reduce the air conditioning load and roof longevity. The heat gain through the ceiling is made up of 3 components, convection, conduction, and radiation. All three of these components have values for heat transmission that are based on whats referred to as delta T or the differential in temperature across the ceiling. This means if you attempting to keep the indoor temperature at a constant, whatever the thermostat is set to, reducing the temperature on the other side of the insulated ceiling, the attic, will reduce the heat transfer. Increasing the natural ventilation in the attic by increasing the intake, (soffit), vent and increasing the exhaust ventilation, (peak, gable, stack, etc.), will help the attic temperature approach ambient temperature. Usually ambient temperature is quite a bit cooler than most attic spaces during summer peak. Powered ventilation does the same thing as adding natural ventilation without the need to cut a bunch of additional holes in the soffits and roof. Of course if the additional ventilation is not sized appropriately, it may not perform as anticipated or cost more to operate that offset benefit.

[@captainobvious9188]

I live in the southwest corner of Utah. My roof already had soffit and large gable vents but the inside of the roof sheathing and trusses would get to about 190 degrees during the summer, and the air in the attic to 160. Installing a 1200CFM attic fan brought both temps down about 40 degrees, allowed my top floor to get cool, and my power bill to drop about $100 a month. I do live in the desert where it peaks at 115.

[@brianm545]

Reduced noise from a new window is always nice. We live on a busy street and its definitely noticeable

[@krazzygranny7032]

you also have to look at more then just the energy savings with replacement windows, especially when you get the Low E coating along with say Argon gas this not only has the benefit of energy savings but also provides UV protection that protects furnishings and floor coverings from early fading and damage and the comfort of life value, as long as they are also installed correctly

[@ShortyzProductionz]

I might slightly disagree with attic fans. In my garage attic during the summer it will get extremely hot and if I need to get something out of it I don’t want to go up there with it being super hot. I put a box fan at the opening blowing cooler air in and pushing hot air out. Within an hour the temperature in there is comfortable to go up there. Now how would this be different than an attic fan permanently installed?

[@irrision]

It isn't any different. Matt needs to actually test this stuff himself before spouting off about it. The utility companies wouldn't be providing energy rebates for window replacements, smart thermostats and attic fans if there wasn't science that showed it reduced their energy load.

[@ELIRAXPRT]

i'm willing to bet the box fan pushes a lot more cfm than these solar fans. A quick search on Menards website shows 800 to 1100 cfm. A box fan i saw on Amazon was 2400 CFM. I've used box fans to cool my house and it seems to help. I'm too lazy to read the article Matt mentions but I'm finding it hard to believe its really that big of a problem with negative air if there is adequate soffit or gable vents. Where I live in the north its not really common to have ducts in the attics.

[@goodtimestxphotobooth985]

Because now it’s no longer an attic fan. You just said you put a box fan AT THE OPENING blowing cooler air in. That’s not an attic fan- that’s a box fan, at the attic opening, pulling in air. Attic fans are at the roof deck. Attic fans can’t outpace the amount of heat being constantly produced by the sun.

[@rolturn]

I am pretty sure he said powered attic fans not attic fans in general, but I could be mistaken.

[@bufootballa]

I'll chime in on this as well. I have to disagree about the attic fans as I actually had 5 or 6 of them installed several years back (we have one of those large 2 story roofs that a portion of it actually covers the entire rear of the downstairs level as well, so we 2 placed in the areas above those lower level rooms and the rest in the upper sections of the attic... It's a big attic, trust me) . We built our house in 2010 and in the summer time, our AC just couldn't keep up with the heat in the Austin, TX area and I realized that the if I ever opened the attic access, it was like opening the hatch to a literal blast furnace and the sweat would start running before I could make it up the ladder. After getting the aforementioned solar attic fans installed, this made a HUGE difference and the same ac system no longer had difficulty keeping the house comfortable. Also, on another of his points that I'll disagree with, I switched to the exact Google Nest Thermostats with the Airwave feature that he mentioned, but I don't think he understands how they actually work bc they do have humidity sensors and that helps determine when the Airwave will run. That being said, I firmly believe a lot of these thermostats are not made equally as I switched from Vivint Smart home thermostats (one upstairs and one downstairs) and ever since going to the Nest thermostats, we don't have to set the temperature nearly as low as we did before (my wife is the meat locker temperature type and would set that Vivint one at 66 or 67 at night and with the Nest during the same 90-100 degree temp days, she only needs to set it at 69 or 70). Usually just setting the upstairs one to 70 or 71 will keep the up and downstairs extremely cool and comfortable. This is all running from a single large ac system for a ~2900sq ft home.

[@Normalhumman]

The other thing he misses about attic fans is that most attics have another side vent that is passive. Most modern houses have soffit vents and that’s where air gets pulled from. So when the fan creates a negative gradient the air enters from these side vents (basically it will always remain atmospheric)

[@mannys9130]

Bingo.

[@averyalexander2303]

Not true. If the pressure in the attic remained atmospheric, then there would be no air entering through the soffit vents. To create airflow, you need to create a pressure differential. As he said, the same pressure differential that draws air in through the soffit vents can also draw conditioned air out of the house through holes in the wall top plates, holes around light fixtures, etc. Also, one of the main rules for attic ventilation is that you NEVER want more than one type of vent on the roof. Most houses already have ridge vents, turbines, etc, which don't play nicely with power vents.

[@luke-i1w]

@@averyalexander2303 The pressure differential is what drives this air movement as you say, but big 2 foot by 2 foot vent holes on either side of your attic is gonna let a lot more air into the attic from outside than all of the combined nail size and smaller holes in the ceiling. Air is gonna take the easiest path with the least resistance. That's fluid dynamics 101. Sure, some will come from the house, but 95% of it at least is coming in through those vents.

[@JasonsGuideToThings]

@@luke-i1wzero should come from the house. Anything more than zero coming from the house is too much

[@luke-i1w]

@@JasonsGuideToThings I agree, but I also understand that people building houses are not perfect. The barrier between the attic and the house interior is going to have some holes in it. I never say anything is 0% or 100% because in the field, that is an impossible standard to reach.

[@catjensen847]

Window replacement for me, saved me about $150 to $200 a month. I am in Dallas Tx area. I didn't change anything else.

[@chrisripplinger]

Wow, a lot of attic-fan hate from Risinger but I'm not seeing any case studies, just theories. Let's do an attic fan test! Check the attic temp. and the ceiling temp in the home, see if it makes a difference and by how much. Also would be nice to test radiant barrier stapled inside an attic.

[@stipcrane]

I am also skeptical of his theoretical pontifications. If you have 300-400 s.i. net-free area in the eave vents, how could that little fan possibly create enough negative pressure to suck gobs of air out of light boxes and walls? Matt is not the only one who pooh-poohs the attic fan-Joseph Lstiburek trashes them also. I think they are harmless at worst and mildly helpful at best. I have never seen a controlled test, yet these fans have some very dogmatic adversaries.

[@alanr745]

Tests to prove otherwise would be nice. Best I can tell, his argument comes from math, which no one seems to want to disprove.

[@Nettechnologist]

I have a radiant barrier and an solar attic fan and when my attic fan died, i definitely could feel the difference in the house, until we replaced it.

[@mediamattersismycockholste562]

I happen to have a tester in the form of a 12x20 short gambrel shed (see big comment above) with an off grid powered (fabbed) 900cfm 12 volt fan in a mushroom style passive roof vent. On a 95 degree day the back of the plywood right under the shingles is 125 degrees (no insulation yet), and that fan running at full speed does not change that one whit. And that's with 3 windows open.

[@jwalkinshaw]

I have a thermostat in my attic. It makes a 10-15 degree difference in the summer with 1 powered attic fan running

[@TheSeanUhTron]

Another benefit to getting new windows is noise reduction. I noticed a significant difference when I replaced my single pane windows with double pane. But yeah, I would never replace good, unbroken and functional windows just to try and save money on heating/cooling. I mostly replaced mine because they were the original 1949 windows and were falling apart.

[@ronaldmcdaniel2378]

He makes some good points about the attic ventilation. Overall, though, the concept of an attic fan does work. The solar gain through your roof heats the attic 30-40°F hotter than the ambient air. That load transfers through your ceiling to the living area. An attic fan draws the cooler (by comparison) outside air into the attic forcing the hotter attic air up through the ridge vent. Here's the formula for calculating the required CFM (Cubic Feet per Minute) of cooler air: CFM = BTU/hr ÷ (Delta T * 1.08) Where... ●Delta T (°F): Attic Temp - Ambient Temp... the maximum allowable difference between the attic temp. and ambient temp. You'll want this at around 10°F. So on a 90°F day that attic will reach a max of 100°F. ●BTU (British Thermal Units) / hr: The heat gain through your roof system from the solar radiation per unit time. Dependent on your climate zone, roof type, color, orientation (South is worst, North is best for minimizing heat gain; opposite is true if you want to use solar panels), time of day, etc. ●Air Constant of 1.08. You can look up the derivation if you want, but this is a constant for calculating CFM when air is involved. This would be a different constant if you were calculating CFM of water, e.g.

[@mrpumba2147]

I can tell ya that I lowered the temp in my previous home nearly 5 degrees by installing a powered fan. They do work and happy to say I'm putting another one in my new home.

[@majorburke9735]

I just changed from single pane to dual pane windows. I opted to buy the ANLIN brand. Check it out, it’s much better than the other brands, however, they are probably twice the price. The amount of air that passed through the cracks was ridiculous, but I live in a mild temperature area of the country and I wasn’t having any water leaks. Let me also say, I would not have done it if my neighbor hadn’t decided to install a fire pit with tiki torches. All his smoke went right into my house! That being said, I am so glad I replaced my windows and sliding door. The small amount I’m saving on air conditioning and heating is irrelevant. The windows are so nice (and no smoke). Just one final note: Buying new appliances or windows or anything else to save energy does not pay for the new appliances. Just buy new stuff when you want to buy new stuff. Just remember, the old stuff is better quality. And you may be better-off fixing your old stuff.

[@teenapittman4241]

The old stuff is absolutely better quality. I have a thrift store and see a lot of old stuff and new stuff pass thru. Especially stuff salvaged from older homes; as in, light fixtures, ceiling fans, sinks, freezers, fridges, even fireplace mantels. Older, small and large appliances are far better. I have an older washing machine, dryer and refrigerator in my home. The front loading washer just wouldn't get my clothes clean, the counter depth,(it means too small) digital fridge kept locking me out and needing repairs. The older stuff breaks too, but I can repair it myself in a timely manner instead of weeks or even months waiting for a warranty repair man.

[@ariel_monzon]

My smart thermostat is awesome. The geolocation feature kicks it on when I am on my way home and leaves it at 76-80 when I’m not. Also, seeing the reports for the unit showed me I was cooling at the wrong times.

[@pierremorris5337]

Attic fans are not a ripoff. Proven to work effectively

[@OmarEwert]

No

[@izfidaAJ]

#Yuhhp

[@donmohave]

I know of Whole House fans for your attic to be good. Is there a scenario where an attic fan will work good?

[@charlesferguson2641]

Attic fans also increase pollution in the house.

[@decaprio7421]

Coolsdown my attic by 8 to 10 °F and fresh air blows continuously throughout my house👍

[@rossrogers84]

Heat transfer through a plane is ( I believe) linearly directly related to the heat difference, so cooling your attic air seems to make sense to me. Lowering the attic air temperature from 130F to 110F could lower the thermal migration from the attic to the top floor ( cooled to a round 70F) by 33%, if my very poor memory of thermodynamics serves me right.

[@DanielNebergall]

no fancy science to back it up but i was thinking the same, 20 degrees would be a fair hope and worth the 75 bucks and the install i did myself......hopefully

[@johnhaller5851]

The issue is that you would be better off spending the money on insulation or air sealing. The operational cost of the fan in a well insulated house is higher than the energy saving on air conditioning. If course, this is a bit of a tautology, as if there is a higher savings, it means the house is not well insulated building.

[@rossrogers84]

​@@johnhaller5851 You're right. You gotta do the math and factor all the variables. Assuming you're air tight on that ceiling plane already and you take out the cost of electricity by buying a solar attic fan ($200 cost + install labor? == $300?) then you can get an exactly comparable benefit by just adding 50% more R's to your attic. ( If I'm using the right formulas..) So if 50% more R's is more than $300, you should do that. If 50% more R's in your attic is less than $300, then you should do the solar attic fan. [Assuming assuming assuming...]

[@randallthomas5207]

Matt, I know that my Father installed a powered attic fan to the house my parents had, in Boulder City Nevada, and in the 1970s when he did it the attic fan coupled with enlarged gable vents, pulled the attic temperature down by 30-F. Since in those days code only required R19 attic insulation, it actually saved him power on his electric bill because it decreased the heat transfer from the attic into the house. And, it seemed to have an effect on the life of the asphalt shingle roof. The original roofs on the whole subdivision were installed over a 9-month period, with my parents house being one of the first ones built. His roof lasted five years longer than any of the others in the subdivision. And, as a water conservation feature, capture the condensate from the air conditioner, and feed it into a capture reservoir as part of the landscape watering system.

[@Lakelandcowboy69]

When my new ac was installed in the summer in Florida, my ac technician said he could not believe how cool my attic was during the afternoon due to 2 small attic vent fans that were scheduled to come on once the attic temperature reached 90 degrees. This also helps prolong the life of the roof . I totally believe in attic fans and whole house fans. They are NOT a scam. Im going to put a solar powered attic roof fan on my rentals now! The ac sure does not kick on as often and doesn't overwork itself. This is just common sense.

[@tommywwalden1599]

@Lakelandcowboy69: I 💯 agree with you comment! I installed powered attic vents on my roof 20 yrs ago. And the benefits have all been positive!

[@firstlast1732]

I put a fan in my attic and it lowered the temperature only slightly but where the real benefit came from was keeping the air moving I never got any mold or mildew in my attic always was very clean for the 20 years my fan ran during the day never even hard much dust either. I had ridge vents in my roof so there was no negative air pressure that affected the vents

[@ashishpatel350]

those attic fans are good at pushing out heat in the attic....not saying youre wrong but sit in an attic without the fan on and turn it on it is noticeable.

[@IanSlatas]

He's wrong. Convection is an incredibly effective method to move heat. Pulling outside air through a hot attic and over the hot surfaces warmed by radiation cools the surfaces. This is extremely easy to demonstrate and I'm honestly shocked that anyone would argue otherwise. The negative pressure point is valid only if there's not enough makeup air opening for the cfm rating of your fan or if it's extremely far away.

[@chaseoes]

They do cool down the attic, but the problem with them is that most houses aren't airtight and it's pulling most of the cool air from the house rather than the soffits. So it might cool down the attic, but that doesn't mean that it's helping your energy costs when you're losing cool air from inside the house due to them.

[@ashishpatel350]

@@IanSlatas most attics have vents in them. I forget what they are called... The ones under the overhangs. But it's far better than not having them.

[@augustreil]

@@chaseoes, If your ceiling has more air flow than full length soffit vents, you'd have serious trouble trying to heat that house.

[@IanSlatas]

@@ashishpatel350 The vents under the eaves are called soffit vents. They can be utilized in combination with a ridge vent for passive ventilation. Attics that need to move a larger volumetric rate of air than soffit vents can supply can be coupled with gable vents or other intakes. Very effective stuff.

[@Schrimpieman]

Attic fan for Hot-Humid climates: As long as your living space is air-sealed from the attic, then having a fan with adequate CFM pulling hot air out is beneficial. After all, what's the purpose of roof turbines or ridge vents? Air currents seek the path of least resistance and as long as there are enough soffit vents, any negative pressures induced by forced air (fan) in attic space, cooler air will enter thru soffits. Having said that, the correct balance of CFM vs attic volume needs to be established. A fan too small won't accomplish anything, and a fan too big consumes more electricity (energy) than is recouped by heat transfer from attic to living space. It's all a balancing act. Have it engineered correctly with air-sealing and proper insulation, your attic will thank you (by having forced ventilation aka "Attic Fan).

[@phillijp]

Cooling your attic isn't for the benefit of a cooler living space. Attic insulation satisfies that important job. Cooling your attic protects your roof sheathing and shingles from burning up all summer long. The cooler they are the longer they last. So while I agree the attic ventilation is important for the sake of your roof I'm not sure that the cost and electricity of a fan is money well spent in most residential construction.

[@sprockkets]

@@phillijp Think here bro: Do you really think your attic temps actually influence the temps of your roof tiles when they are in the sun? They don't. That's the whole point of the analogy of you being in the sun on the beach with a fan on you - it doesn't do anything at all.

[@Blue04Z71]

Attic fans work. Installing ac units in attic spaces or working in an attic without a fan is terrible. With a fan it’s bearable. Maybe in Texas they don’t work but here in PA they do.

[@leonpse]

I think it depends where you live for attic fans. In dry mild area, the sun does not immediately heat up the air in the attic. It takes a 2-3 hours, but that heat can stay in the attic all night. The outside temperature could be 55-65 degrees, but inside is 75-80 degrees until 3-4 am on the top floor. So the AC needs to run almost all night, but an attic fan can blow out the hot air after 5:00 pm when the sun is not as strong.

[@mgfray7657]

I think the key thing with smart thermostats is that they make your house more comfortable (in general). In my case when I went from 'dumb' to smart thermostats the comfort level was vastly better (far less swing in a radiant heating system from high to low temp). I did notice a SMALL amount of energy savings. The remote control and comfort was more then worth it for me.

[@leanybrian]

Also, if you have vacation homes you can save a ton of money in avoiding frozen pipes in the winter and cooling in the summer when you’re not there. I let my house sit pretty close to 80 unless I’m going to be there. Then I can cool it down starting in the morning before I get home. Also, I have a dual zone AC that was never balanced. Now I have assignable temperature sensors in every room and the thermostat does a good job at consolidating them into a comfortable average

[@JohnNeville617]

They are also great for turning down/up the temperature when you haven't moved for hours while you binge watch TV and schedule thinks you are asleep.

[@bhami]

Seven years ago when we re-roofed, we put in a solar-powered fan on the attic roof of our unheated garage. The roofer was emphatic that it needed to suck air in from outside, not exhaust. It's probably not a huge deal, but I like the idea of that storage attic being, say, 110 F instead of 130 F.

[@williamnaman3570]

Did you actually measure the before and after temperature? You should really get the cool air from inside your garage space because it will make that living space cooler.

[@leestevens446]

@@MAGAMAN Once again, Matt is talking primarily about his climate. Job I remodeled 45 years ago in Upstate NY was similar to what you are describing, and it was well worth the effort. The attic hatch was over the garage, there was an intake grill at opposite end of the ranch house gable roof from the exhaust fan, the the wet heat was run in the basement, and there was no AC and no can lights (this was back in the day, one canopy fixture per room). The Universal Answer is, as always "IT DEPENDS".

[@MrNside]

@@leestevens446 Yeah, I've installed power gable vents (one side power, the other side just a vent) during several siding jobs on 80+YO homes, and they work incredibly well in my experience. Put them on a thermostat and set it to 105 or so, and the AC runs much less. For around $400-600 including labor (during a siding job) it can pay for itself rather quickly. It's also really helpful in 2-story older homes with retro-fitted central air, where the upstairs always tends to be much warmer.

[@kylemiller769]

@@MAGAMAN nb;

[@flyzipper]

Replacement windows... reasons to pursue, other than cost savings: improve passive ventilation (+comfort and -mechanical ventilation costs), increase natural light (-electricity bills), improve views (+enjoyment), increased security.

[@jaspersonnyoner]

Noise transmission is reduced also

[@olympicfireball]

Surprised he didn't bring up double to triple pane.

[@raysonviswas]

@@jaspersonnyoner yeah i used to live right next to the train tracks and you can barely hear the trains at full speed, I live in the UK where new windows tend to be double pane.

[@dreuthanasia1]

@@olympicfireball sadly North America is way behind on moving to triple pane. hopefully we see many people switching over soon, but with big houses with many windows it isn't a cheap operation

[@jaspersonnyoner]

@@raysonviswas In urban environments I would opt for triple glazed for noise benefits alone, closing a window can be like closing a bank vault door

[@SoaringVideos]

Here again I have to disagree on the smart thermostat. For him to say to never leave your fan on all the time is not a good idea. As an HVAC technician I have found that with the high-efficiency ECM motors or variable speed motors running at a low speed all the time there is very little draw on the electricity. This also allows cooler air from the basement to make its way up to the upper levels and some of the two-story upper levels that are hotter because heat is rising is now bringing that hot air down and mixing it with the home when the AC is off. I leave my fan on all the time to help balance the levels of my home making it more comfortable. Filltering the air all the time and humidifying in the winter time when needed as I live in Colorado. Also smart thermostats allow us to be able to use Geo fencing when you’re not around the temperatures can change to put less demand on your cooling and heating system and overtime that can also save you money. Now I know letting your house get to 80° and then trying to drop it to 70° in the summertime is not an efficient way to do things but you can change it 3° or 4° and overtime that could make a difference. Also digital thermostats have cycle per hour limits that minimize the amount of on and off a system will encounter. This of course puts less wear and tear on your heating and cooling system. I would completely disagree that smart thermostats are not a good idea. There are even more reasons to own a smart thermostat that I didn’t mention here. I’m just not seeing the science behind what he saying. I guess I’m realizing I need to question his channel. Here in Colorado I’ve seen a huge difference in homes with single pane windows that have changed to double pane windows. I’m not claiming the savings numbers, but it is significant and when you factor in the comfort, and air infiltration and more why would anyone not upgrade their single pane windows to double pane? I get he’s arguing the savings with numbers but I really think this whole video was a bad idea and should’ve never been posted. My opinion of course 😀

[@MikeM-bn2ij]

I think what Matt is trying to say about attic fans is they are a bandaid not necessarily a fix. My attic would reach 150 in the summer and take forever to cool down. I thought about getting a fan but after digging into it I decided to try to make changes. First was insulation,which didn't lower the temperature in the attic but helped in the house. I needed a new roof so had a ridge vent installed at the time and it seemed to help but temperatures still got to the 130s.i then cut holes in the soffits as there were only a few so I could balance the intake and exhaust but it still got in the 120s. Before I resolved to get a fan I tried one last thing and that was an external baffle ridge vent. So now, with the soffits vented properly, the attic insulated properly and the internal and external baffled ridge vent the temperature stays within 20 degrees of the outside temperature. I've found all the same benefits and more. My attic doesn't even get to 120 unless it's over 100 plus degrees. If I'd have gotten the fan in the beginning,sure my house would be cooler with the fan but the attic would still exceed whatever temperature I set the thermostat up their to before it would cool down. Another way to explain my situation is in the begining my attic temp would climb quickly and stay hot until late into the night. Now it's the same temp as outside only climbing a few degrees higher, typically within 10 degrees all day and dropping to match the outside in early evening. Hottest temp I've recorded is 20 over hence why I said that earlier. Sorry so long winded. Hopefully this helps others. Sure 2nd third floor issues makes it difficult to do what I did, easier to just install an attic fan but again the underlying problem isn't solved. So just depends on what you want

[@eodhowland]

I had the windows replaced in my 1770 sq ft ranch home in Baton Rouge Louisiana. I saw an immediate $40 per month savings on my electric bill. I also noticed that my HVAC was able to cycle instead of running constantly. I agree with the comfort statement. I have a large 6 ft by 6 ft window in the dining area that was unbearable in the afternoon due to full sun. After installing the new low e windows, I no longer felt the heat radiating through the window. After watching your videos, I know there is more that I could do to continue to make my home more efficient, but new windows was a great first step for my home.

[@eodhowland]

@bobwatters I actually don't enjoy living in a cave, e.g. what it would take to make the curtains useful. I like to enjoy the fruits of my outdoor labor from the comfort of my home. Replacing the windows cost me about $5K. I'll see a good portion of that back once I sell my home due to the update in appearance to the home. And at $40 a month, I see almost $500 a year in lower electric bills, I am not having to have my HVAC worked on almost monthly and I was able to extend the life of my HVAC system. So, I am damned sure that I will come out just fine on this purchase.

[@ericgustin3386]

@bobwatters how bout stopping the cold in the winter? they make curtains for that? lol. northern climates and resale value. those are the 2 reasons to upgrade your windows from single to double pane insulated. Good luck selling a home with single pane windows. and in a northern climete like maine or mass? forget it. single pane is a joke. you get a MONSTER high heating bill in the winter, and to top it off , your house is never really warm. where do you spend most of your time? in the living room usually on the couch. whats behind the couch? two big fucking windows, thats what. and single pane in the winter up here will literally be blowing ice cold air on you.

[@bobp1016]

We put in new windows and it also made a big difference. Our old windows would almost burn you. The new windows are cool to the touch and our kitchen that’s gets the morning and afternoon sun is now nice and cool. Before the new windows it was always hot.

[@berniehaberberger7821]

@bobwatters, not curtains... removable solar screens on the exterior of the windows would've solved this guy's problem for a fraction of the cost of new windows. The solution is to stop the sunlight from ever hitting the window in the first place. A curtain will do little good. At the point which the radiant heat from the sun hits a curtain, it's too late...the heat has already entered the home. It heats the curtain which radiates the heat into the room.

[@berniehaberberger7821]

@@eodhowland, I don't know, so I'm only asking..is your hometown hot enough every month of the year for you to see that $40/mo savings?

[@dlwatib]

Sorry Matt, attic fans are the bees knees, you just have to be smart about installing them. Of course you don't want to draw conditioned air from the house up into the attic, nor do you want to depressurize the attic. The alternative? Attic vents in addition to the fan so the fan draws outside air in and circulates it. You're right that the sun is cooking the air inside the attic. That's why you need to remove it and get it away from contact with your living space. Even on a 100 degree day the air outside is going to be cooler than the air in the attic. If the outside air is 100 degrees, the air in the attic might be 120 or 130 degrees or even more, so the attic fan can get rid of as much as 30 degrees worth of heat in the attic. If you're worried about pulling conditioned air in from your living space, either add extra attic ventilation or mount the fan so that it pulls air into the attic rather than pushing it out... and of course plug up any air leaks in your ceiling and overhead ductwork. As for smart thermostats, not every place is as humid as the south. Here in the west every bit of summer humidity is welcome. Before air conditioners were available we used swamp coolers which are very effective in cooling the air, but add humidity. Blowing air over the condensate will evaporate it, which will cool the air, and the small amount of extra humidity won't be enough to make you uncomfortable. You'll get maximal energy efficiency out of your air conditioner.

[@robertj1777]

I replaced old single pane windows in a home in the high desert with low e windows. When I started the job the house was hot by 9am and needed ac. When I finished the house stayed cool and didn't need ac until around 3pm. It's the only time I've done this but the results seemed pretty significant.

[@Cspacecat]

About 10 years ago I got an estimate for a new roof. It was going to cost me about $4,000. Instead, I used White Roofguard 700 for trailers on my worn-out shingle roof. I used a roller and pole to push the sealer under the shingles, laying them back down. My attic used to be 130F to 140F in the summer. Now it is 5 degrees above ambient temperature midday. Using this sealer about once every three years gives you a forever roof. That white roof is cheaper than the fan and is 1/3 of your air conditioner bill. Figure $75 for 5 gallons every three years. Several years ago, I tore out the sheetrock off all external walls. I repacked them with 3.5" fiberglass. I glued 1-inch aluminum-backed Celotex insulation over the studs and then applied 5/8 sheetrock over that. I then mudded and painted. That makes an insane amount of difference. I have about 18 inches of cellulose insulation in the attic. That didn't matter because summertime heat will radiate all the way through the insulation. I removed all but one egress window on the east side of the house and all but 1 egress window on the west side of the house. My house is painted high gloss white. I set my programmable thermostat to turn on at 10:00 pm and pull the house down to 70F. At 4:30AM the thermostat is set to pull the house down to 68F until 10:00AM when it turns off all day. That keeps the air conditioner from running during the heat of the day. My 3,400 SQ.FT. house costs me about $110 to $120 per month during the summer on the electric bill. Last month's electric bill was $93 because of the cold front and I stayed home and watched KZbin all day. Last month's gas bill was $59 and of that $30 was the service charge.

[@xiangli2452]

Does not make sense at all on attic fans - I can attest that adding active fans do a lot of cooling to the attic. The bonus is that it can extend your roof life by reducing the heat stress to the shingles.

[@sethpriser4811]

Matt, love your channel and agree with almost everything, but I can't on this one in regards to attic fans. If your attic is vented properly at the eves there is no way an attic fan can create a negative pressure in the attic. The primary install for us in the Chicago area is on a 2 story house with a single furnace. The upstairs is 10 degrees warmer than the downstairs even if you restrict the downstairs vents and leave the upstairs open wide. The A/C will struggle to ever bring the 2nd floor in to submission. An attic fan solves this problem easily. Another point you missed is that of humidity. Most current models come with humidistats built in to them as well. With mold being such an issue, this feature is worth it alone if your attic is staying moist even though you've vented all your exhaust fans to the exterior etc. You really need to re-think this one.

[@sprockkets]

Nope, he's right. If you have issues with hot air attics, you don't solve it with an attic fan. That's outdated 25 year old thinking. You have ridge vents that don't need active cooling and you insulate properly.

[@jpcreativeimagery]

Of course it's struggling, closing off the zone is your first issue. Any knowledgeable AC guy will tell you not to do this as your creating a build up of static pressure that will put unnecessary strain on the system. Many people think that is okay and saves energy but it doesn't, forced air is forced air all the time, you can't stop it or reduce the load by closing a few vents, this will only cause shorten the life span of the system over time. This only would work if the zones were both on their own systems.

[@LordDeadSpider]

JM M Attic fan solved my heat issue. Easy to install and did not cost much either. It is not outdated if it works as intended.

[@ejohnson3837]

especialy after the sun goes down.

[@eggnogaddict6287]

Wrong. A ridge vent takes care of this. By using a powered vent you’re actually pulling cold conditioned air from your living space into the attic regardless of soffit setup. You’re combining passive intake with powered exhaust-a complete imbalanced system.

[@chefsantos2847]

Wrong wrong wrong . I purchased my house on 2016 and we were paying around $350 to $450 per month on electricity . Replace the ac unit without the smart thermostat and the bill did not change after two months I got a new smart thermostat , a month later replaced the windows to a double glass . My bill now is $225 in summer time and $125 in cooler months. My next door neighbor had the food fan and he replaced the roof last year , he was paying $175 last summer and this summer his bill on $250. Hey men I respect you for the great job you are doing here but this is completely wrong. Your points are from contractors perspective.

[@kennethmc2601]

Yea man, he never even got into the pure convenience factor of a smart thermostat, which was enough for me to buy one.

[@jeffrobison2013]

we are in Sw Missouri, dad had a 1930s farm house that had large single pane windows. on a windy day you could see the curtains move from air leaking in. he had siding and new windows installed and it was like a new house. cost to heat and cool went down dramatically

[@bearded4glory809]

The thing people don't realize is that the old windows could have been refurbished for less than the cost of new windows. Do you think that in 1930 there was air blowing through a closed window? No...They need to be maintained.

[@genli5603]

@@bearded4glory809 Crappy old aluminum windows aren't worth it to refurbish, if it's even possible.

[@andrewdavis9021]

@@genli5603 1930's farm house with (original) aluminium windows... I think you will find they will be timber windows.

[@timahern8670]

you might see that the savings came from the cavity around the window behind the trim. most old windows even from 80's are not well insulated when they were originally installed. Pull trim board and you will see air gap. That mostly where air leak and heat/cooling losses happen.

[@pandeomonia]

Fine, but Matt is specifically talking about the thermal difference and energy difference between one pane of glass and a multipane glass window, assuming all else equal. The issue with your dad's windows were they were fitted poorly, were uninsulated, etc.

[@krpinckney]

Appreciate your input on Solar Vents. I'm here in Texas and was thinking about getting some 3 years back. Chose not to because of this video. Now I got wind damage due to a storm and need a new roof. Decided not to get solar vents once again... Because of your video. Thanks so much.

[@OnHoldAt50]

We had 40 year old single pane windows, and after much research, chose a medium-high-end double pane double hung (for cleaning) Argon filled vinyl frame windows all the way around. The vinyl was a special composite, but it was the glass itself that was appealing to us. One side is thicker than the other so that they resonate at different frequencies. Any neighborhood radios blasting at my house are now completely gone. There's more noise permeating the walls themselves. Like moving into a new house. Texas energy savings is still profound. ** True if you're upgrading double pane to double pane- meh increases in efficiency expected.

[@MediumRareSteve]

this video isn't aging well 😂

[@billgujie]

maybe the attic fan doesn't work in TX, but it definitely worked for us in N.California, with noticeable room temperature improvement.

[@tmiranda1379]

Same here

[@DanielinLaTuna]

It’s nice for when I gotta get into the attic in the summer time. It ain’t cool up there, but at least it isn’t 150. 95, maybe

[@ptom711]

Did a study years ago for a couple utility companies and the state on attic venting. It made no difference on house temperatures. None. Zero. Zilch. As long as there is a thermal barrier, I.e. insulation. Attic temps in N. California reach 180 in attics with asphalt shingled roofs. No heat transfer through R-38 insulation to the living space. They also didn’t cool the attic down very much, if at all. It is thermally impossible to cool your house down by cooling your attic down if there is a thermal barrier between them. If there is no insulation a better option is to insulate it, not power vent it.

[@psdeas7530]

Are some commenters referring to whole house fans vs attic vents? Whole house fans are crazy effective. www.fixr.com/comparisons/attic-vs-whole-house-fan#cQ

[@billgujie]

@@ptom711 the difference will be a formula of ambient temperature, heat transfer from attic to living spaces, how much volumn of air can attic fans move per unit of time, etc.. I believe the result of your study, but I also like to believe maybe that study does not cover some of the commenters (like myself) particular parameters. But it would be nice if they can publish the paper. (Or maybe I just live in a badly maintained home 😂)

[@Scuba_Bro]

I have a wired attic fan that has actually helped cool it down. I have numbers to back it up too. It helps with the AC in the summer.

[@lzh3131]

I came across this video and really found the information invaluable, I do live in South Texas and humidity is an issue. Thank you very much for this information, you saved me money.😊

[@savabadanau1825]

This guy never failed the science class! Guess how?. HE NEVER ATTENDED IT!!!

[@chall1mk]

My dad, who was an electrician, put in his own attic fan with a thermostat set to 80°. It saved the house from really cooking in the summer. House built in 1963.

[@cornillious1]

Same. Huge difference in my house that was built in 1900.

[@PwNaSaUrUsxLEET]

Yeah, he's wrong on this one. An attic fan alone won't usually solve the problem, but it is part of a multi-step solution. I've had them make a big difference in numerous houses, including my own.

[@LibertyOrDeath7230]

Can also be very useful at venting humid air that has leaked into the attic from the living space.

[@wudchk]

They're good if you seal off the rest of your house

[@MrNside]

Well, in his defense, he only does jobs that are new construction or complete renovations, and he insulates the roof, the rafters, and would probably build a giant umbrella that would block the sun from reaching his customer's property entirely if he finds a rich enough client. "Why spend $500 installing a fan when you can spend $15,000 installing a new roof with 6 inches of foam insulation?" ... A true salesman.

[@brockspencer5949]

A lot of inaccurate or at best misleading information in this video. Comment section is filled with correct information and testimonials. Just as weather barriers have to be installed properly to work so do all 3 of these "rip offs." A powered exhaust fan will not work without proper soffit venting, smart thermostat won't work unless programmed correctly and of course windows need to be installed correctly. I would say this one missed the mark by a pretty wide margin. Your building science teaches me something almost every time, when you start talking about mechanical systems and how they work i.e. your take on tankless water heaters and all of this video it seems to be out of your field of expertise so maybe shy away from it and use the resources around you who have a better understanding.

[@LagMasterSam]

Yeah. If you're getting detrimental negative pressure from merely running an attic fan, where's your venting? I don't understand how someone's attic could be so lacking in ventilation that running an attic fan would result in so much negative pressure that air from inside the house gets sucked into the attic.

[@ouagadougou62]

I completely agree with you, a 60 degree heat reduction is a ridiculous claim. that said, I installed an attic fan in the two houses that I renovated, the difference was instant. I would estimate the temperature drop between 5 and 10 degrees Celcius. We don't have air conditioning in the house and it gets to 35-38 degrees for weeks. We live in Japan. I also painted the roofs silver from dark brown. that also makes a huge difference. Most houses here too are painted dark brown or black, I don't understand that. I installed the fan on the west side to draw cool air from the east. The fan cost less than $100, the paint, I had to repaint the roofs anyway so no extra cost involved. It turned out to be one of the best expenditures that I did.

[@Matthew-gl2kf]

That's primarily because he's talking about homes with AC that are supposed to have an air tight envelope which is compromised by the attic having a negative pressure, pulling in the expensive conditioned air out of your home into your attic. If you don't have AC, this doesn't apply and it would actually be a GOOD thing to pull hot house air up through the attic pulling in cooler fresh outside air into the protrusions of the house.

[@johnbecich9540]

Paint, even silver paint, is a mediocre radiant barrier, at best. Look it up; I'm not making this up. Repeat: you are claiming to have cooled your attic by applying a silver coat of paint to reflect sunlight from the rooftop. That's called a "radiant barrier." A better way is to install aluminum foil, shiny side DOWN, inside the attic, sub-rafter. Also, it helps to have eave vents (intakes) and ridge vents (outflow). Your paint simply cannot compare; and it will accumulate dust and lose its effectiveness.

[@leestevens446]

​@@johnbecich9540 The essence of a radiant barrier is reflectance rather than adsorption. If the lighter paint color absorbs less and reflects more, it is acting as a radiant barrier. It has the added advantage of reflecting that radiant energy into free space, and NOT back into the underside of the roof sheathing, so the effective utility of the roof paint is greater in that application than an equal reflectance within the structure. People make this mistake in assessing Low-E glass all the time. If the Low-E layer is anywhere EXCEPT the outer face of the outer pane, then a portion of the reflectance is converted to heat when it hits the pane on the outgoing pathway, and then conduction and convection come into play, dumping more heat energy into the structure than the reflectance numbers of the coating would imply. FWIW, BSC has documented roof fails due to converting flat commercial roofs from black EPDM to newer white elastomeric. The white is not a mirror, but it has been (devastatingly) effective in some hot climate zones.

[@philkline4673]

I don't hate you brother. But I install these for a living. They absolutely work! I have gone in and taken temperatures in the attic before and after and it definitely lowers the temperature in the attic. Combine that with radiant barrier and it is close to the ambient temperature outside. Which in turn shortens the amount of time that the AC has to run for which saves money on the electric bill. You're not wrong with the thermostat or the windows but the solar attic fan is a great product that works well.

[@Rapture9999]

With all due respect your understanding of the science is half correct. Radiant energy heats up the shingles, and that heat then transfers into the attic via radiation and convection. However, even if the air outside is very hot on a summer day, with an attic fan you’re forcing air flow through the attic that is colder than the roof. This reduces heat transfer from roof into the attic and results in a lower attic temp. This as a result reduces the heat transfer into the home because the attic is colder than it would be without the fan. Source- I aced thermodynamics in college and I have a bachelors in metallurgical engineering. I know heat transfer pretty well.

[@jessilane2240]

Your analogies don't make a lot of sense. Houses ventilate their attics for a reason. The heat from the shingles heats up the air in the attic. Ventilation helps singles from getting too hot, which will result in a reduced life span (you can see heat blisters on homes with poor roof ventilation). Attic fans are good to use as supplements to traditional ventilation when there are limitations to traditional vents (think a small ranch with a ridge vent on a hip roof). While they can create a negative pressure in the attic, proper sealing and insulation can reduce the effects. Your attic insulation will be more effective at reducing loss when you decrease the temperature difference between the house and the attic. I haven't even addressed the issues of thermal shock on the shingles and moisture build up in the attic (hot humid attic vs cold drywall).

[@williamnaman3570]

@@PersonalStash420 He builds new homes with conditioned attics. He believes in passive measures to ventilate conventional attics. His point is the relative efficiency of a 12" fan cooling a giant heat sink with sun adding heat during the process. When I asked him for advice on a 60s attic, he recommended as much additional passive ventilation as possible.

[@williamnaman3570]

@@MAGAMAN when you replace your roof it is easy to add ridge vents. Matt recommended I do that. As far as cheaper, my solar vent ranges from $300-$1000 before installation. I think my ridge vents added less than $2000 to my roof replacement on a 1800 sq ranch from the 60s.

[@95thousandroses]

@@PersonalStash420 There is absolutely such a thing. If you put an powered attic fan in an attic with no or little soffit venting then you create a vacuum in your attic which will then pull air from any tiny crack/gap from inside the conditioned home. A terrible situation. And these fans aren't cheap to run for 8hrs a day @ 300watts either.

[@IanSlatas]

@@PersonalStash420 I agree with your ventilation claims, even though I don't have soffits on my 1830's home, just a very short eave that's pretty much solid wood. I guess this isn't a common scenario where you are but around me it is with 19th century homes. The ventilation is done with a fan in each gable, one pusher and one puller. Works a treat.

[@zefrum3]

Firstly, in order to get proper attic ventilation, the house needs Soffit vents. Ive seen a lot of house in Houston TX that only appear to have soffit vents and surprisingly a lot that dont even appear to have vented soffit. So long as yhe house has a ridge vent, the roof will cool passively and well. Secondly, if you interrupt the flow of soffit air someway up the rafter bay, you are creating a shortcut for the cooling air to exit. eg Path of Least Resistance. Thirdly if u power that vent, it pulls air from where ever it is available, which is a radius of least resistance. Which means it will pull from the ridge which will be hot air from above the shingles and it will be cool air from the air leaks in the attic floor. Thermodynamics isnt an easy subject especially on a complex system like a house.

[@birajbhandari3518]

I would do a CFD Study on Attic before I make that claim !

[@captainmigs1655]

What’s cfd

[@Guillotines_For_Globalists]

@@captainmigs1655 Possibly "Computational Fluid Dynamics."

[@adamUDavies]

I too could tell the difference in the summer when my attic fan would run. It helped my house 🤷🏻‍♂️

[@jaye9300]

Did you hear Matt mention it pulling cool air from your openings in the sheetrock? He didn’t say it wouldn’t work, he explained why it’s a bad idea. If you don’t believe him, go in an old house with a whole house attic fan. (The ones for cooling living space). Slightly crack open a window and turn on the attic fan. It’s shocking at the large amount of draft it will pull.

[@BrBill]

@@jaye9300 But Matt's talking about those roof fans, not attic fans.

[@michaelbagwell3485]

@@jaye9300 I think you are confusing the whole house attic fan mounted in the ceiling below the attic with what Matt is opining on the powered roof ventilator fan which is very beneficial in some roof attics with poor conventional soffit or eave ventilation.

[@yehudagoldberg6400]

So I went to the article you linked regarding attic fans. The big flaw is that it assumes everything else is perfect. Perfect envelope, perfect insulation. But most of our houses are far from perfect! We are just trying to get comfortable. So even is there is absolutely no energy savings, even if it costs an extra $25 a month, the bottom line is that in most cases, an attic fan will make an imperfect home more comfortable. I got quoted 10k to redo the insulation in my attic. Instead I just installed an attic fan for a fraction of the price.

[@cyrilasfrenchyaz]

Airwave is recommended in AZ. If the thermostat doesn't offer it, energy auditors recommend to enable the fan switch delay on the air handler/furnace. According to them, it may save up to 10% on the electric bill.

[@gustavlicht9620]

AZ is pretty dry compared to Texas though. As with everything - horses for courses.