ERV vs. HRV - Myths

[@nuegithao9103]

From good ol wisconsin and we thought the same. HRV up here and ERV down there, but the problem is what about the summer? we'd have to turn off the HRV (if customers remember to) otherwise it'd get too humid in the home. So we just go with the ERV instead and be able to leave it on year round while bringing in fresh air.

[@jasonkilley]

My thoughts too, with his point about humidity I was about to say over here in Minnesota the summers are extremely humid, and the winter's extremely dry. So it seems like an ERV for me

[@bobcat9314]

So is this the general consensus..common sense would tell me..spend once, cry once and dont worry about humidity..spring for the EVR? Thank you..im almost ready to purchase. Just doing more homework

[@jaywardlumber]

Matt, really appreciate your channel and all the info you provide. I'm a lumber dealer in Northern NY and we just started stocking the Panasonic line including the cold climate version of Intelli-Balance 100. ERVs can work in the great white North now to provide the humidity transfer benefit of the ERV. Keep up the great work!

[@jonathanlabrucherie9676]

Great explanation! One thing I would say is that Minnesota is definitely a place for an ERV because, while the midwest is known for its long, cold winters, its summers tend to be hot (80-100F) with high dew points (60-80F).

[@maxdoe8812]

Just a observation , its good practice to dump the incoming air in to a basement or unused space, this will prevent nasty droughts and noisy air flow in the living area. This can be noticeable in the heating season. I installed mine 14 years ago and it still runs perfect. I run it on a dual out door low and high temp, and out door high humidity sensor to optimize the loading.

[@superspeeder]

Matt, recovery ventilators add humidity in the humid south and that also means they remove humidity in the cold north since cold air holds little moisture. For a given amount of ventilation an ERV will dry a house out less, allowing it to run more without lowering humidity too far. Unless you have a super tight custom built house an ERV may be the way to go up here. Most ERVs have much lower operating temperatures than HRVs before freezing/defrost becomes an issue, which also leans toward using an ERV up north. Super tight houses that need to shed large amounts of humidity may need an HRV instead if an ERV doesn't get rid of enough moisture.

[@bobcat9314]

Your the man..I love your channel..thank you for your much needed contribution to the building industry..we need more people like you to keep us in the know of all the new products hitting the market.. This is an amazing product..every home should have one of these units

[@technorex344]

In the north an ERV is recommended instead, HRVs can make it too dry due to the humidity outside in the winter and people get uncomfortable and turn the units off, losing the benefits of ventilation. An ERV will help retain some of the moisture produced in the home by moving it to the incoming air stream, as more to less.

[@justchillinout2002]

The reality is this is completely regional. In Calgary, we are too dry and have to add moisture to our air. Go to Ottawa and you need to dry the air. There is no silver bullet. The reality is a professional HVAC designer should be consulted.

[@technorex344]

@Dan You're not wrong. An ERV will make it drier, I only meant it will help retain some of the moisture in comparison to an HRV which will not retain any of the moisture.

[@Jonny-wn1fl]

@@technorex344 hey guys I am an hvac contractor in Minnesota and I continue to go into houses that the HRV'S are running non stop during the summer and have to explain to the homeowners on how much load they are adding to the ac especially with how warm this year has been. On top of that one of the local inspectors decided to make contractors wire the HRV'S to run continuously 24/7 365 and so now I will be switching to ERVs for that reason it only makes sense if people need to run them during the summer as well.

[@jasonkilley]

@@Jonny-wn1fl Hi there, I'm thinking about putting an ERV in our cabin here in Minnesota. It's just baseboard heat and through wall AC, so we don't get any air movement or fresh air. So I figured it's a no-brainer in the summer because you get fresh air from outside and the ERV removes some of the humidity, but in a strange twist for me, In the winter I actually want the ERV to remove humidity because the cabin is sealed up enough that with even a few people in there for a day or two the cabin becomes very humid, and I actually want some of the dryer air to come inside. It gets so bad that the humidity condenses on the inside of the windows and causes mold. I already have a dehumidifier in the basement but I might have to get one on the second level if the ERV doesn't solve it.

[@Jonny-wn1fl]

@@jasonkilley Jason the ERV will actually remove moisture in in the winter just not as fast as an HRV. Minnesota winter air is typically super dry and that's why an hrv running in Minnesota almost always needs a humidifier which is why you see HRV'S paired with an aprilaire whole house humidifier.

[@jimdrewty]

In my experience in climate zone 5 with radiant heat systems we can see high humidity levels inside a tight house. Now this is only my experience I am by no means a expert but in those houses we build we do see a drop in indoor humidity by using the ERV. I think the reason is because of the cold dense air has less moisture per volume than the indoor air we are exhausting out. Anyway I can tell you that you can achieve proper RH levels by using your ERV in the dead of winter but as for spring and fall there is little to no change. Keep the videos coming your an inspiration to the young generation of contractors including myself 👍

[@ericjuli6576]

In the (hopefully) near future I plan on tackling the job of building our first house. Loving all of your videos. But, being in FL and considering an ICF with conditioned attic, this one is something I’ve been looking for! Thanks for all the great info

[@markwillride]

We installed that Panasonic ERV in the new house we just completed, thanks partially to your video on it when it came out. I expected the temperature of the air dumped into the house to be an average of the outside air and the indoor air. I was surprised to see the air coming in to be about 64 degrees with indoor temp at 68 and outdoor temp at 41. I really should check that again by another method because I don't understand how that could be. As far as the cost of the power it consumes, its going to be under $3 per month with electricity at 11 cents per Kwh. It's really quite at 50cfm, reasonable at 70cfm. But at the full 100 cfm, you can hear the output into the house from some distance. I used the purpose built grill and boot they sell for this ERV. A better method would be a standard HVAC boot and grill that had much more area. The Panasonic part has straight edges inside the grill that cause a lot of the noise. Rounding those over with a dremel but the noise to about half. The intake in the house is very quite though, even at 100 cfm. Thanks for sharing all of your knowledge, tips, and time with us. I with we had tested all of our new Anderson 100 windows for frame leaks before the siding and brick went on. Yep, one of the leaked. A dab of silicone solved the problem but that's a patch, not a fix.

[@Crusader1815]

quite adverb \ ˈkwīt \ Definition of quite 1 : wholly, completely not quite finished 2 : to an extreme : positively quite sure -often used as an intensifier with a quite a swell guyquite a beauty 3 : to a considerable extent : rather quite near quite a bit : a considerable amount quite a few : many XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX quiet noun qui·et | \ ˈkwī-ət \ Definition of quiet (Entry 1 of 4) : the quality or state of being quiet (see quiet entry 2) : tranquility on the quiet : in a secretive manner : in secret quiet adjective Definition of quiet (Entry 2 of 4) 1a : marked by little or no motion or activity : calm a quiet sea b : gentle, easygoing a quiet temperament c : not interfered with quiet reading d : enjoyed in peace and relaxation a quiet cup of tea 2a : free from noise or uproar : still b : unobtrusive, conservative quiet clothes 3 : secluded a quiet nook XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Thank you for trying to improve your literacy so you stop making the rest of us dumber by having to tolerate your presence.

[@LTVoyager]

It sounds like the unit is not properly balanced. If you have more air going out than is coming in, the incoming air will be warmed more. This makes though that you are causing more air infiltration in your home to make up the difference that isn’t coming in through the HRV. Most ERV/HRV installation manuals are quite specific about the air balancing.

[@zachary3777]

It's a cointerflow heat exchanger. The intake and exhaust flow across each other in opposite directions, so the heat exchange is more efficient than parallel flow or crossflow.

[@swtexan6502]

Thanks for the information, Matt. We installed an ERV that is manufactured by a small company in Ohio called UltimateAir. It is one of the most efficient ERV's on the market (98% Heat Recovery Efficiency). Since we are in Central Indiana (Cold and Humid), ours also has an integrated 1kw internal heater that pre- heats the incoming air and allows it to continue working in very cold climates. We love it.

[@technorex344]

They had some good ideas. Too bad CoViD knocked UltimareAir out.

[@swtexan6502]

@@technorex344 Website is still up and active- are they out of business?

[@technorex344]

@@swtexan6502 Haven't been able to get ahold of them in over a year, and I receive calls every few weeks from customers who also can't get anything. Used to be able to call Luke directly- his phone now only goes to voicemail.

[@swtexan6502]

@@technorex344 Well, that's not a good sign. Love their product.

[@technorex344]

@@swtexan6502 Decided to give it another shot and was able to get ahold of someone who used to work there! They said last they new (6+ months ago) UltimateAir had 1 person working there 1 day a week for filter orders (on Tuesdays)

[@virgil3241]

Straight forward and to the point. One of these have been on my list for a few years now, but an HRV. Northern at 0 degrees, we wish. Try -35

[@TheGuitarShawn]

@Joe You don't have to go very north at all to get below 0 (Fahrenheit) occasionally. It was a pretty warm winter this year; I remember it hitting -3, probably went below that too, just sayin'.

[@virgil3241]

ok, but -40 is -40. -17 is a warm day

[@jaywardlumber]

You can use the cold climate version of panasonic's ERV in any North American climate zone. Model is FV-10VEC1. The ERV allows the cold climate dwellers to retain some of the moisture of the home by transferring some of the humidity from the exiting air over to the previously bone dry air coming from the outside. The ERV doesn't add humidity like a humidifier but moderates the existing humidity in the air.

[@christophergruenwald5054]

The coldest days don’t count. It’s not uncommon for us to hit -20 several times in SD during the coldest months. But the daily average temp never gets near there. I’m running a fantech shr3005r HRV in my house. Dual core, extremely efficient, but during maybe 3 months of the year it’ll bring in a lot of humidity if I run it frequently. I looked into getting ERV cores to swap out in the summer, but that was a bust since for the 2 cores they wanted $2500 (double the cost of the unit in the first place) I might end up swapping my HRV out for a ERV in the end and moving the HRV out to the garage for dehumidification in winter after melting or washing vehicles, trailers and equipment. The HRV works great though in winter for removing humidity from the house, probably to good.

[@ArneJohanssonMpls]

This was perfect timing for this video. Matt, you should talk with Pat Huelman about these. He works with the University of Minnesota and the Department of Energy building and testing high performance homes. I think he would be a good resource for you to see what he thinks about ERV and HRVs up here in Minnesota. He has been installing them for years up here.

[@rochamusicx]

So if I live in Maryland I should use an ERV? We are right in between the weather pattern, Cold dry winter (not as cold as Minnesota of course but freezing temps too) and pretty humid summer''s.

[@jopetroni]

Matt, I've been binge-watching your videos all day. I'm an architect and this stuff in precious!

[@Bobbylegs37]

"If you're in Minnesota, you won't need an ERV." Bro, you have no idea what our summers are like 😭

[@davidbruce5377]

If you bring in warm humid outside air to the ERV - exchanging with air from the bathroom and kitchen, is that not counter to the units function, given the bathroom/ kitchen air has a level of moisture. Perhaps waste outgoing air should be picked from a dryer area of the home. The unit is depending on clean dryer air to treat the incoming humid air. JAT

[@N41haul]

If the indoor air is more humid than the outside air, then some of the indoor humidity will exhaust outside through the ERV. If the outside air is more humid than the inside air, then the ERV will cause the inside air to become more humid. However, you must understand that a stated RH is affected by temperature. For example: If the outside air is 56% RH @ 40°F, and if this same air was heated and moved indoors, the indoor relative humidity would indicate approximately 13% RH @ 80°F, in contrast to when the air was outside and indicated 56% RH @ 40°F. RH is deceiving, for it tells you the percentage of humidity that the air can hold at a specific temperature and pressure, it doesn't tell you actually how much moisture is in the air. Dew point tells at what temperature moisture will condense out of the air at specific atmospheric parameters. Absolute humidity tells you how much moisture weight is in a volume of air, and is expressed in grams per meter squared. Absolute humidity should be used in determining actual moisture content between two different temperatures of a moving air mass. Cold air cannot retain as much moisture vapor as warm air, so with a given weight of moisture in a given volume of air, at a specific atmospheric pressure... Relative Humidity will differ with temperature, and its percentage will increase when the air is cooled and moisture remains unchanged. If moisture in excess of the ambient amount is exhausted from your bathroom, and if the bathroom is heated more than the rest of the house, the RH of the bathroom will read less than the rest of the house, which is cooler in temperature. BTW: how many hours a day do you take a hot shower in the bathroom and boil water in the kitchen to make this a significant concern over a 24 hour period? With either an ERV or HRV the indoor air is constantly being replaced with fresh outside air and any excess humidity beyond ambient caused by a hot shower or boiling water will soon be exhausted outdoors.

[@dormarchan7230]

Can you hook up pipes that are coming from the bathrooms, kitchen, and laundry into a common junction and goes into the ERV exhaust outlet?

[@TechnicalLee]

Yes, however this won't replace a bathroom fan because it will not draw enough CFMs from the bathrooms if the exhaust is split up. You typically need 50-100 CFMs to prevent a bathroom from steaming up from a shower.

[@jeanlanz2344]

Thank you, Matt. You are a great teacher.

[@roBLINDhood]

Great video. One note, the hottest/most humid summer I’ve ever experienced was in Minnesota. ;)

[@BradleyPrescott]

Land of 1000 lakes. Super humid in summer.

[@Bob_Lob_Law]

@@BradleyPrescott 1000 lakes my friend? That is lame. I live in a province of 10000 lakes.

[@harrisleck3960]

@@Bob_Lob_Law Manitoba for sure!

[@Bob_Lob_Law]

@@harrisleck3960 👍

[@shadshriver1541]

Thanks for the clarification. Makes perfect sense.

[@buffydog21]

Yes, HRV are a 1/3 of the price. I live in the north. Where we have 6 months of cold and the 6 months are a mixture of climates.

[@robertocorradi6318]

Thank you Matt . . . Very helpfull and informative as always . Your a natural at presentation .

[@aadams0921]

Best explanation I’ve been looking for

[@sickre]

I wish these were common in Europe - mostly there is just zero ventilation. Apartment blocks have air exhaust through the bathroom fan and intake through window slits, if they're lucky.

[@jasonhunter6125]

I'm from Bergen, Norway. A cold place with lots of humidity. (80% relative humidity mean year). I'd go for an ERV, then.

[@EPICSOUNDTRAX]

The same thing is where I live in Quebec Canada.it is mostly 80% humidity and very very cold in the winter it can go to -40C

[@judaharise777]

Great video and explanations. Thank you. Anyone have knowledge about how these units work with homes built with SIPs? The house will be really tight and we're in Atlanta where it is super humid. I've been told that an HRV is what I should go with but I'm not certain I don't need a dehumidifier also. Appreciate tips!

[@michaelrowley6069]

I am enjoying this video. I seem to have an opposite issue than what you face in the south. The area in Utah is arid and cold. What heat exchanger/recovery unit would you recommend to humidify the house and recover the heat? Should I just install an automatic whole house humidifier?

[@sparksmcgee6641]

Doesnt add humidity

[@barbaramills288]

We have a very simple whole house humidifier hooked into our ancient furnace. Similar to a swamp cooler (simple motor with a rotating pad). Works great; whenever the furnace is blowing hot air it is humidifying that air.

[@michaelrowley6069]

@@barbaramills288 Thanks

[@davidcrawford1402]

What are the advantages with using an ERV with a whole home dehumidifier versus using just a whole home dehumidifier with fresh air intake? (Ultra Aire's website is pretty clear that their opinion is that an ERV/HRV is unneeded.) Only reduced energy loss?

[@TechnicalLee]

Yes, without an ERV all of the heat and humidity of the incoming air will need to be removed, vs. less with the ERV. Less energy. ERV also reduces the energy use and drying of air in the winter.

[@emmittjesse7443]

You prolly dont give a damn but does anybody know a trick to get back into an instagram account? I somehow lost my password. I love any help you can offer me

[@henrykendall6294]

@Emmitt Jesse Instablaster ;)

[@emmittjesse7443]

@Henry Kendall thanks so much for your reply. I got to the site on google and im waiting for the hacking stuff now. Looks like it's gonna take quite some time so I will get back to you later with my results.

[@emmittjesse7443]

@Henry Kendall it worked and I actually got access to my account again. I am so happy! Thanks so much, you really help me out !

[@LUEO103X]

Most if not all HRV's will draw moisture from the air, hence the condensate drain line.

[@scottclute9547]

Matt is very brilliant!!!

[@monroejosh]

In an installation with both an ERV and a whole-house dehumidifier, how would you prefer to duct those? Should the ERV fresh air be run though the dehumidifier? Many dehumidifiers have fresh air intakes, it seems that should pull from the ERV.

[@DHMADNS]

I would like to know the same.I am about to install this unit in Northern California on the coast and having humid winters and nights year round I want to add a dehumidifier as well.

[@katmcreynolds6096]

@@DHMADNS Did you find an answer to this?

[@katmcreynolds6096]

Did you find an answer to this?

[@gedionsamuel2256]

Anyone know the answer?

[@audex]

how about places who are more oceanic like oregon or seattle ?, in winter we have almost no snow (not like east coast) so it's humid and cold and in summer is around 35% relative humidity in the day and 80% in the night.

[@christophergruenwald5054]

What is the dew point? RH tells you nothing without temperature to determine DP. DP tells you the saturation point of the air and the saturation point changes with every degree of temperature.

[@audex]

dew point in summer around 48 º - 55 º and in winter about 30- 35 so the mornings are very foggy even in summer and after 11 AM or so it gets "normal"

[@rodwoolley1549]

Its worth keeping in mind that cold air can have a high relative-humidity but contain little water. This is perhaps easier for the ordinary person to understand than talk of dew points and temperature. Not only do ERV's and HRV's save on heating and ventillation costs, but they reduce pollution from out-gassing of cleaners carpets and paints etc in household air (and body odours!) and reduce particulate matter ie dust as well. In modern well-sealed houses, it can also be hard to keep CO2 levels down, and the ERV/HRV works very well in this regard.The ERV does not reduce household humidity but it helps prevent the air exchanger which is needed for ventilation from bringing in too much water when it is warm and humid outdoors. IN all but temperate climates, modern houses need air exchangers.

[@notkyleschultz]

Hey Matt, huge fan of your work & I love this channel; I've been here since September of 17'. I just wanted to say that the way you showcase products, present complicated issues while elegantly sharing your knowledge km how to solve problems, as well as explaining complex design techniques in easily digestible & consumable language is fantastic. You are not only doing KZbin diffent than other builders but you're doing it better. Anyways I'm curious about these type of products & have a question for you. Filters aside & given how affordable adding an erv/hrv to a built can be: is there any reason that you would be unable to run two units inline for a single home? Obviously these units aren't 100% efficient & no matter how many you add to a system you'll never reach 100% efficiency. However is there any advantage or disadvantage that you can think of if you ran 2 in tandem? Like perhaps for a passive house build or situation where the goal is to be as efficient as possible? If you had to speculate, do you think there would be significant difference in the intake air temperature after going through both heat exchangers? Or is there an efficiency limit you'd run into once the air gets below a certain temperature differential? I'd be interested to see some data of a system w/piggybacked hrv's. Hopefully I was clear enough for you to understand because I'd love some feedback from you. Cheers

[@wiengo509]

You generally used broad categories for which unit to choose. Minnesota and the surrounding states have very stuff and humid summers but also cold winters which are emphasized by the humidity. It seems to me that the ERV would be the way to go, according to your description. The upper midwest has 4 distinct seasons. Any further direction or thoughts regarding that? Thanks for the great, helpful video.

[@notkyleschultz]

I live in MN & I understand what you mean. An important thing to note about erv's is that they are passively exchanging humity. Which means you can not meter or control the rate or direction that the humity is gonna flow. The humidity will always transfer from the higher humidity side to the lower humidity side until it reaches an equilibrium; ie exchange moisture for as long as there is a differential in humidity. That makes it desirable in parts of the country w/high humidity. Since the air in your house is gonna be dryer than the intake air from outside, an erv will exchange some of that moisture from the the intake side to the exhaust side (high to low.) since this system functions passively, this wouldn't be desirable someone like me who lives in MN. Because of how dry the winters are & the nature of which an erv transfers moisture in the system. I would constantly be dumping moisture from the inside of my house (higher rh) to outside (lower rh.) Running the heat exchanger during winter would force me to actively condition the inlet air to raise the rh in my house. I would be fighting against myself & the system non stop by artificially increasing the rh in my house; because the higher the moisture differential is, the erv works more efficiently. You know the whole 1 step forward 2 steps back thing. You could run an erv in cold climates but that means any system that you use to regulate the rh in your house is gonna have an unnecessarily heavier load during those winter months. Having a stytem with a hrv & actively controlling the humidity independently would not only be more effective but be more cost effective to run. Realistically in colder climates, any moisture exchange that an erv offers during the summer will quickly be outweighed during the winter months.

[@mrjephrey4276]

Where would you mount an hrv in a new construction. Also where would you go thru the wall will it?

[@Big_Mike_1116]

while and ERV or HRV is designed for whole house ventilation, what would you recommend to use in place of or in conjunction with a bathroom fan or a stove exhaust? could the stove exhaust be coupled with an ERV? would it be better to have an air purifying dehumidifier built in to a bathroom as opposed to an exhaust fan?

[@christophergruenwald5054]

You can’t install in place of range hood. The grease will wreck the cores. But in my house I installed this instead of fart fans with timers in every bathroom. Any time you hit the timer it bumps the unit to high for a set time. Any time the unit runs it pulls air from every bathroom in my house (4). That’s 4 fart fans I didn’t have to buy or install. That aren’t loosing energy, running loudly or penetration to the exterior of the house.

[@jmo6722]

Love the cost of the filters too

[@fadinoir4057]

HRV pulls a greater delta causing condensation across the core in cold climates. HRVs have condensation drains ERVs do not typically.

[@rockslide4802]

Matt: You still have yet to define what an HRV or an ERV is. Don't assume people know or have watched a previous video that explains that. Not everyone is a builder. Some of us are just homeowners. That's why I am here watching this video. What is it, what does it do, how does it work with my existing or new HVAC system? What does it cost? Features yes, but what are the benefits?

[@stari6840]

Is recuperation system that work like Windows just much better(without lost heat and plus they are compatiple with climatisation) and they are mainly for passiv house (house with minimal 90% efficient)

[@johnnyrambone]

Question for you knowledgeable folks... I am in the desert, very dry, four distinct seasons with hot Summers and cold Winters. I am thinking HRV, but I I would gladly pay extra for ERV (if cost is the only reason not too), if it keeps more humidity in my house for health etc, than an HRV would. Thoughts? I just keep hearing my climate can go either way.

[@joshualucero8256]

I live in a warm area. Not quite desert, but it can reach 118F in Summer. Humidity will drop to low teens. I have two ERVs - it's a large house and I was looking for 250cfm. With one small AirCare (wick-based) humidifier, I can maintain 40-45% humidity inside. In the extremes of Summer, it can reach 38% at a minimum. I refill with 5-6 gallons every three or four days. This humidifier is made for a medium room, but the ventilator helps distribute it evenly throughout the house. If I had an HRV instead, I believe one humidifier would not be enough. I tried the humidifier in different spots and settled on an area near an ERV exhaust intake (where the stale inside air goes to the core, on it's way outside.) The humidifier is set 5% higher than my target humidity. The ERVs run for 20 minutes each hour, on low speed. Used in this way, it's been very consistent and comfortable. I almost never open windows now, and there is much less dust. As a side note, baking bread is also more consistent with stable humidity. Whatever you get, make sure you have good access to the unit for cleaning and replacing the filters.

[@johnnyrambone]

@@joshualucero8256 thanks for sharing your thoughts

[@jeffchoi]

I remember a few videos about how if a house isn't airtight, negative pressure from the HVAC system would result in outside air being pulled into the house to compensate. Would ERV/HRV help with negative pressure?

[@jaywardlumber]

Jeff the ERV can be balanced so that the house is neutral so there's neither positive or negative pressure.

[@jeffchoi]

Thanks Jay, now I wish I knew about these during my house construction.

[@jaywardlumber]

Jeff I'm with you! I renovated my own home in 2017 and installed another brand HRV before I became a stocking dealer for Panasonic. Had I known them what I know now I would have installed the Intelli-Balance 100 ERV in a heart beat!

[@portwolf2293]

Matt Risinger so, what's a solution with same benefits for range ventilation hoods over 300 cfm and bath ventilation in an air tight house?

[@MrBrianDuga]

Great post. Love this stuff!

[@managemold]

Minnesota needs air exchange all year round. Also dehumidification 7 months of the year.

[@cirlleemolandjr3342]

I have a ultra-aire 150h and have no clue if its working as its supposed to.

[@greggsaunders3246]

I am really interested in this idea but have an old (1890's house) that is really leaky. How do these units perform in these types of structures? Any links to literature or other info would be greatly appreciated.

[@teemoney8087]

What if you're somewhere colder, and you want MORE humidity inside to prevent the dry air from making you sick? Does an ERV add humidity?

[@Lewis.Alcindor]

During the cold & dry winter months, an ERV helps preserve the existing indoor humidity by exchanging the exhaust air's water vapor to the fresh filtered air coming in. However, it's not a 100% transfer, so you will always lose some of the humidity in the air exchange process. To keep the indoor air more moist, you have to lower air exchange volume and run the ERV at a lower CFM, at a rate somewhere above the minimum recommended but well below the maximum rate.

[@teemoney8087]

Thanks. My basement is way too dry. Keep getting sick.

[@AudioHouseOnline]

I'd like to see a video on how you use the ERV and a dehumidifier in the same house.

[@flybyairplane3528]

AudioHouseOnline typically these are in 2 different locations. Say Florida nowadays, the air handler is on a stand in the garage , and there will be no condensate leaks from ceilings, so relatively easy to use a DEHUMIDIFIER HERE. The other unit HRV is elsewhere. from Maplewood nj

[@briannelson2856]

I was thinking the same thing, are they installed as stand alone units (independent of each other) or are they ducted together ? if they are ducted together I would like to see an install video

[@frankly2677]

If you have exhaust fan vents and a fresh air damper, would it not make since that you have a balanced house? If your hvac is putting positive pressure on the house, your house is air tight except your vents fans. The flapper on the vents is one way exhausting out. The positive pressure is going to force air out of those vents even tho the fan is not on. So the benefits of me installing an ERV is moot is it not?

[@rickrudd]

What about central virginia where it snows in the winter and is 100 in the summer?

[@777cascade]

Great video as always

[@wildman8601]

Do these do anything w removing moisture n humidity out of basements ??

[@thousandleaves]

Only if your exterior air is less humid than your basement air, and you will want an HRV instead of an ERV to prevent moisture exchange. It will pull the air from inside, ostensibly your basement if you duct your exhaust there, and replace it with air from outside. You might see better performance from a dehumidifier.

[@wildman8601]

@@thousandleaves yea def going w a dehumidifier just seen commercial style and sized ones need to handle this moisture down n get it out too much sneezing and sniffling going on every day

[@jakebower2952]

I program HVAC (mostly commercial) and I have heard the myth many times that ERVs will dehumidify a building. I have a question though, how does an ERV even dehumidify the incoming air? Because the air would still need to be brought down to its Dew Point especially if the air never mixes right? Obviously there are some cases this will work but say you are exhausting 72 Deg F air out of your house through the ERV (it is likely a higher temp than that even) then the only way I see that air dehumidifying outside air is if the outside air is 75 w/ 94%RH, or 76 w/ 89%RH, or 78 w/ 84%RH, or 80 w/ 79%RH, or 82 w/ 74% RH, 85 w/ 70%RH, or 87 w/ 66%RH. Basically what I am getting at it is has to be a very humid or very hot and uncomfortably humid day. And thats to get the moisture content of the air down to the equivalent of the exhausted air in this scenario. Am I missing something?

[@darrickhock]

Doesn’t the ultra air pull in fresh air as well ? Do you need both?

[@DyseRLJ]

In dry hot climate of Phoenix AZ, would an HRV help keep the heat from coming in while still bringing in fresh air? In such a situation where I am trying to keep the house cold, which unit is best?

[@LightStrikerQc]

I live in a 6th floor condo. I want to add an air exchanger. How do I pass ductwork in an existing 12" high ceiling? Is there anyway not to destroy the drywall?

[@whit6119]

So if you have a home in the south. High humidity outside, dehumidifier inside and erv do you just never open windows?

[@christophergruenwald5054]

whit unless you want to bring all that humidity into the house.

[@ilyakononchuk9598]

Matt, what is your experience of using and recommending a Ductless ERV? I have a small 600 sq ft cabin in the Southwest that is extremely air tight. It is heated via wood stove and radiant floors and its cooled by a mini split. It has a kitchen hood and bathroom vents. I imagine i would need an ERV if i dont feel like cracking open a window. Ducted is not an option. Appreciate feedback.

[@phillipnunya6793]

Does anyone know of a good mini version of this ERV that would work fine for a forty foot shipping container?

[@N41haul]

It's not going to drop the humidity out of your grow barn

[@DmitryDrozdovPenza]

Panasonic makes a single room version too which costs just over 400 bucks

[@phillipnunya6793]

@@DmitryDrozdovPenza Thanks.

[@magnussenpaetur]

How about climates in the north that are cold and have high humidity? For instance, where I live, in Faroe Islands, today it's 45 degrees Fahrenheit and 95% humidity. Would an ERV be better here?

[@williammackey7243]

You make the best videos, can you do a video with an application of an ERV (or HRV) with a MVHR system with semi-rigid all room evac?

[@weirdsciencetv4999]

I made a custom enthalpy wheel and found it outperformed the typical ventilator. Why did i get better results? Obviously a wheel is more mechanically complicated than a plate exchanger, but still.

[@roberto.gallegos]

I’m in Colorado. In the winter it is super dry. Would this help this issue in the winter and make it more humid

[@Whammyboarder]

Question...So I work for a builder that is building a super insulated house. There's a 16 inch envelope around the entire house from the exterior 2x6 to the interior 2x4 studs. This 16 inch envelope is completely insulated and like i said, this is around the entire house. So the house has an HRV system but no heating or cooling system. There is no HVAC system in the house! None at all! I am skeptical that the house doesn't need some sort of HVAC system to either cool or heat the home, given that the house we are building is in the northeast...Boston, Mass to be more specific. Can someone please confirm that the house does indeed need some sort of HVAC system such as mini splits to cool or heat it depending on the time of year?! Mind you my boss is set on just having this HRV system and doesn't even plan on installing any sort of HVAC system at all! Isn't that just madness? The walls are getting closed up too right now with blueboard which is driving me crazy! Sure the house might be super insulated and airtight but regardless, won't you need some sort of source of heating in the winter and cooling in the summer? The HRV simply recirculates air from my understanding around the home; it does not heat or cool it?! Is that correct? Does he indeed need some sort of HVAC system from my understanding? Can someone please let me know?! From the research I have done, the HRV is a great system but does not function as an HVAC system which is much needed in the northeast. Can someone please confirm this or elaborate to me on how the HRV works if i am mistaken? Please and thank you!

[@Whammyboarder]

Can somebody please reply?! SOMEBODY?! ANYBODY?!

[@jeremysgarageandfunstuff6424]

The house could be a passive solar design meaning the sun will heat it in the winter and keep it cool in the summer.

[@nickvasilev]

Hi nice videos thanks, if it is not to much to ask, would you recommend ERV unit for continental Europe where temperatures vary from minus 20 centigrades (-4 Fahrenheit) to plus 45 C(100F)?

[@depaolojm]

Matt - do ERVs orr HRVs also transfer odors from the outgoing airstream to the incoming one?

[@jaywardlumber]

Jason DePaolo in my experience with an HRV in my home there isn't any odor transfer. The volume of air being moved at one time via the HRV/ERV is pretty low compared to the volume of air in the rest of the house. As a ventilation professional once described it: do you pee in the corner to raise the temperature of your pool? My guess is the same analogy could apply to odors as well.

[@stephenkovach2628]

Jay Ward p

[@ابوعمرالشدوي-ر3ظ]

Hi, I want ask if this ERV system work in dusty whiether and hot ...some time got 45 or above f tempreter....please... And there other system for dusty wether???? Thanks

[@mwrcrft]

Hey Matt great video but is there a verifiable test to check the air quality in your home before and after the installation of a erv system. I can not find hard data just recommendations from different experts who cannot agree on a what measurements or tests quantifies the need.

[@gracilism]

Google "Indoor Air Quality Monitors".

[@mwrcrft]

Thanks but I am looking for the science behind the thinking that air exchange is necessary. It seems scientist are a lot like carpenters as when you ask 100 of them how to do something you get 100 different answers and they all think they are right.

[@666dynomax]

Great video.Just installed a venmar evo500 hrv in a cottage. Would you recommend running this unit while not at the cottage during winter? I keep it to 55 deg f while away

[@Chrissi.Pinder]

Is there any performance hit to using an ERV for an HRV application? I am in Virginia, so it is not like Florida or the deep south, but a significant portion of the year is extremely humid.

[@TechnicalLee]

Not really, they are similar efficiency. Only case would be if you needed extra dehumidification in the winter to keep the condensation off the windows, HRV gives more dehumidification than ERV in the winter.

[@lornelepage8437]

Hey Matt, great knowledgeable video....the only comment that I have is that it will work the way you said as long as the unit is installed properly....not a diy’er project for some....leave it to the professionals folks...just my thoughts.

[@chrispratt3265]

Hello Matt. Great video. We completed a house in 2016 based in NH, and our plumber recommended and installed a RenewAire EV300 ERV unit. When the weather drops to -16 which happens about a week out of every winter, we get condensation, and sometimes small amounts of ice build up on the windows. Other than those very cold days, we don't see anything. My plumber advised running the unit more during these cold spells, but I am wondering if, in fact, I should have installed an HRV and or not be running the ERV more during cold stretches as I think I could be adding moisture to the house? RenewAire says I should be running the ERV 60% of an hour during winter but the air coming into the house is cold, and therefore I need to run the heat more. Any insight would be great. ​Thanks

[@cestmoijeet9288]

We are in Winnipeg, Canada and we have issue with humidity in our house lots of fog built up, window freezing, and poor heat installation which make few room very cold. Do we need HRV or ERV??

[@TrimJazz]

great video matt. i am a big advocate for make up air.

[@blakescovers5131]

3:30 shoulder seasons

[@martyy4073]

i live in norway, what do i get erv or hrv ,it can get down to -25 in winter and 25 in summer.

[@beckysmith7517]

Hey I have a question? I have a 200 square foot tiny house with closed foam insulation and because I also use it as a greenhouse in the winter time and of course because of transpiration of the plants and evaporation of the soil after a watering… on top of two adult people breathing, I am getting a lot of humidity in the winter time. I also live in the SW Virginia area so we have pretty humid summers here too. Which system would work best for this application and HRV or ERV? I know both clean the air Im just more concerned with excessive humidity. I see a lot of people in tiny houses using HRV but what do you think I should do. Also I am looking for a very small unit… any ideas there because its again only 200 sq ft?

[@williaty]

Matt, I have a photographic darkroom in my basement in Ohio and need to add ventilation. I'd like to use an HRV to keep the temperature in the room more constant as I ventilate and have it cost me less to condition the air. Are you aware of any small, cheap HRVs I could use for this?

[@walnutcontractors5661]

lunos is small (depends if you have any above grade portion to your basement wall)

[@hawk8743]

Have you used Hebel power panels?

[@julieta203]

Great presentation!

[@tyrellmasterson2717]

What do you use for Very Hot and Dry?

[@thromboid]

I would think ERV, since you want to keep moisture in the dwelling for comfort, especially if you're actively cooling and humidifying the interior.

[@thromboid]

But do measure the actual humidity levels and calculate and compare indoor and outdoor dew points. A/C may not lower the RH appreciably but the dew point will go down.

[@mefarri]

Ok, I've been waiting to ask you this question on the subject. If you plan on wanting filtered, balanced fresh air coming into the house, and also plan on a standalone dehumidifier, wouldn't one of Ultra-air's units with the fresh air inlet be the ticket? Seems like it accomplishes both simultaneously. Or is this plus a dehumidifier better for some reason?

[@MustPassTruck]

If there a version with a hepa filter?

[@jamesmchugo9422]

I’m in southern Minnesota. Your saying I should have an HRV, but Minnesota can get tropical humidity levels, 50% to 90% humidity in the summer normal here. And humidity in the winter can be a problem too. We had a system similar to what you show here where I work, and frankly, it made the work environment swampy. Currently, I use a whole house dehumidifier year around, so... what do you suggest?

[@rayiqiraq]

Does ERV suitable for hot and dry weathers in the summer like Iraq weather were the temperature get to 50 centigrade and up higher ? Thank you for informative video

[@jonesgeorge1990]

HRV or ERV better for Edmonton/Alberta weather? Please help

[@davemorlan7202]

I live on the Oregon coast. My home is 2600 sqft. We have a lot of rain and cooler ocean air. During July through September is an average of 60-75 degrees. The rest of the time is cold and wet. What system would you recommend for that situation? Do they both filter or “clean the air”?

[@sitoramoramikhudoeva4295]

Thanks. Does HRV helps with radon level?

[@timkiserwoodworking]

Do you know if they have a charcoal filter to filter out outside smoke?

[@63ch31]

You could always add a seperate filter unit to the inlet ducting. I think most of these only come with a paper filter.

[@ThornBoyz2207]

I have a 2 flat in Wisconsin with boiler heat zoned separate for each apartment. My main concern is the downstairs apartment. 1,100 sqr ft. I'm doing work down there in preparation to rent out again and will run duct work needed. I need fresh are in the winter but also need to dehumidify in the summer as well as fresh air. So your saying that neither an HRV or ERV will accomplish this? I have a stand alone dehumidifier currently and it is stupid expensive to run. What is my best option here? Also whatever I do downstairs will be completely separate from the upstairs do to sound proofing.

[@gundie22]

Which one would you recommend for Portland OR?

[@shawnsteinman2001]

Do you ever chnage the filter on these machines?

[@morganbryan5890]

Matt (or other pros) what would you recommend for our case? We have a new home, very tight that has relative humidity ~40% and climbs to ~50% after bathing. We were looking to add an ERV plumbed right into our furnace intake...but now am wondering if an HRV makes sense. Our humidity is high enough to cause us to have significant condensation on our windows...goal is to reduce that issue via lowering the humidity. Would love your feedback. Location: Chicago

[@shawnsteinman2001]

Do you ever need to change the filter on these machines?

[@RachelFu-ism]

Why do you need to filter the air that’s going out of the house anyway? The bathroom and kitchen only smells bad; air from there isn’t exactly harmful.

[@worganyos]

If you use gas appliances in the kitchen, then kitchen air IS actually bad for you. But no, you wouldn't typically filter exhaust air.

[@ToddJCrane]

What about dry climates like AZ?

[@MrKanario2]

Which unit would you recommend for Phoenix AZ?

[@ColeSpolaric]

Shouldn't the fresh air be brought into the return air vent? This way it gets filtered and dehumidified before being put into the house. Whole house filtration will be better then what these units can provide.

[@zefrum3]

not without a lot of additional parts like actuated dampers to prevent the ac from blowing return air out through the hrv/erv; and the thermostat to control it

[@ColeSpolaric]

zefrum3 you're still taking air from bathroom fans and hood vents and other exhaust. Just bringing the fresh air into the return side. So I think only a damper would be needed which wouldn't be bad

[@zefrum3]

i originally thought your first comment was asking with regard to an hrv or erv. So if you are trying to bring air in from the outside and condition it along with conditioned air, you will have a lot of problems: condensation, dirty-er filters and heat or cold gain when neither is wanted. As Mat explained, ERVs and HRVs are a way to vent fresh air into the conditioned space without also bringing in as much humidity, pollutants and heat/cold. The main goal is to bring in oxygen without everything else.

[@johnclark7406]

The "supply-only" approach is one way code compliance can be met. It doesn't include a ERV/HRV and the stale air is forced out through cracks in the building envelope. It's a less than ideal approach and not necessarily cheaper to run vs ERV/HRV.

[@zackarybrown2827]

Matt I’ve been thinking about have a whole house humidifier installed for the winter months here in Ohio was wondering what if any whole house system you recommend

[@johnclark7406]

Fix your leaky house first. Cold air is dry and it lowers the humidity of your interior when it gets sucked into your house. Start with sealing windows/doors and top floor ceiling plane.