Installing Jumper Ducts to Make Bedrooms More Comfortable

www.drenergysaver.com | 1-866-607-0191
Climate control and comfort in a home depends on much more than the size, power and efficiency of the heating and cooling system. It depends on proper insulation, air sealing and, above all, it depends on the air duct's distribution and adequate balance between return and supply ducts.
Larry Janesky, founder of Dr. Energy Saver, was recently in Central Florida helping a homeowner with a high cooling bills, and uneven temperatures around the house.
The bedrooms in his house had only supply ducts. The only return ducts were located in the common areas. Using state-of-the-art equipment, Larry demonstrates how the lack of return ducts in this home's bedrooms was increasing the positive pressure in the rooms above acceptable levels, consistently pushing air out of the house, and causing unconditioned, hot and humid air from the outside to be sucked into the common areas of the house. The differences in pressure made the air conditioner work harder, without ever making the whole house comfortable.
When homeowners experience similar problems, they tend to mistakenly believe that they need a bigger, and more powerful heating and cooling system. This is why it is a good idea to call in an energy conservation specialist, before you commit to buying an HVAC upgrade.
In this case, for example, just by adding a return duct to each bedroom, Dr. Energy Saver experts brought the pressure levels in the rooms down to normal. The temperatures are now even around the house, comfort has improved and the old air conditioner now works more efficiently.
If you want to save money, energy and make your home more comfortable, call a Dr. Energy Saver dealer in your area!

[@teakettle7021]

Been watching HVAC videos all day and that bit about the imbalanced air pressure is genius. Thats the most valuable tip I've heard yet.

[@carmelom269]

It would been beneficial to the viewer (me) had your video included footage of your technician actually cutting and installing the return “Jumper” vents and ductwork in the ceilings

[@patrickkelleher2309]

Lots of people will hold your hand. Unfortunately most will charge for satisfaction

[@machinemanbaltimore]

I'm glad to see the home owner cleaned up the place before the video!

[@phildavis5377]

Great explanation Larry. I've been in the sheet metal industry for more than 30 years and after seeing my share of shady contractors I always appreciate it when someone such as yourself shows the right way to do something. I agree 100% in regards to adding individual returns to each room and dampering both return and supply air runs. Great video!

[@jeffcarter8160]

Wow! You just solved my daughters room issues. Thanks!

[@briangc1972]

As an HVAC professional who is a Building Performance Analyst, I can tell you that jumper ducts are a very expensive solution to a simple problem. The overlooked, and very obvious problem is that the jumper ducts are always routed through the attic. Every attic is a solar heat collector, a solar oven. The heat in the attic will heat the jumper ducts (regardless of R rating) and will passively heat the home. I have carefully measured the heat gain during the summer and found that a 4˚F gain is a minimum and often I measure an 8˚F gain. All day long, the heat enters the home via convection air circulation when the A/C is off and by forced air when the A/C is on. As the A/C air enters the room, the equal amount of air is forced through the jumper ducts and is passively hearted by the attic. That hotter than room temperature air is now spreading through the main hallway and gives a false hot reading to the thermostat and that hot air is drawn into the return duct. The result is the return air is now a few degrees warmer from the jumper ducts, which means the supply air is also a few degrees warmer. Our forefathers knew this 200 years ago. Many homes built 150 years ago had transfer air openings above the doorway of each room. That feature in a home was discontinued when central forced air heat and cooling became more common in new home construction.

[@MAGAMAN]

Newer homes have vents through the walls above the doors, which allows more airflow, but they also increase noise transmission.

[@akaLuptonPittman]

Thanks for this reply Brian… genuine service and common sense intelligence seem to still exist. That being said sir, I have an old two story wood frame (balloon I believe) house that was built back in 1921 and could really use some advice regarding a possible mild extension of the supplied central AC to the relatively small second floor. Condenser/handler combined outside unit that feeds and returns directly into the under crawl space. Rooms needed cooling are directly above, sharing an outside wall. My question is if branching off the proximal aspect of the large supply ducting as it immediately departs the unit outside would allow the “physics” of air movement to and fro, to be relatively plausible? I should add that the returns are pretty substantial and only a short distance down an open stairwell. My idea is to construct an exterior cover of some sorts to conceal the ducting as it travels upwards. This inside corner of the house is shielded from direct sunlight and requires only a 10’ max run. From there I’m considering the wall breach to be at floor level… either a direct horizontal feed or put extra work into breaching the floor void space and have supply vents that match downstairs. Any advice would be much appreciated. Thank you

[@964mula]

When we close our bedrooms and restroom , there is a big gap under the door . Would that serve the same purpose ? Now I’m thinking I need to keep doors open . I always kept them closed thinking it would keep the cool in .

[@briangc1972]

@@964mula Closing the doors blocks air flow. Open doors or install relief vents in the wall above the doors (like they did 100 years ago) The gap under the door lets ou the coolest air in the room and traps the hottest air in the room. Relief vents let the hot air out.

[@jph77]

But return air is still pulled from under the door when it's closed. Usually a couple inches or more on new homes.

[@bobstacy4]

Wow. Great video. Now I understand what some of my problems are around here. Now to try and fix them

[@lanesairconditioning]

This is the best explanation I've seen of this problem. Great job! . To the last poster about room stratification. The draw from the return will draw from the immediate area around the grille. The supply will push the air (throw) to the other side of the room. The result will be a good mix in the room. It actually breaks the stratification.

[@fredg5079]

lanesairconditioning .

[@lanesairconditioning]

@Bob Smithereens generally, any given room, from the ceiling to the floor will have "stratification of temperature," when the system is idle or off. When a system is designed well, with proper grille placement, the stratification is broken and the air in the room will get mixed well allowing for a higher degree of comfort. Some grilles may not offer a good mixing of interior air because of poor velocity.

[@boneyfreak9197]

Good job. This is such a common situation. Every home I've ever tested has this situation. New, old, add-ons and unfortunately also homes with newly installed/replaced systems. 99% of Homeowners will drive 2-5 extra miles to save 4 cents on gas but don't understand they're paying 25% more a year in heating and cooling their homes, living with nasty air drafts, hot/cold spots and auto opening and suck slamming doors because of this and other issues with their HVAC system. Then you have the goobs that cut an inch off the bottom of the doors or install a bypass right above the doors or even through the door itself and this eliminates any audible privacy in that room. Depending upon the room load(s)you can often properly air balance existing or install dampers and balance the system. I've actually run into situations of gross over supply with 2/3 supply registers in a room area then often I replaced a supply grill with a 1 or 2 way register to get mixing and made the furthest supply run a return duct.

[@jimbola77]

thank you for sharing excellent presentation!!!!!

[@phxrus]

Nice info, kept it simple so even a homeowner could understand ...

[@yozy4996]

Excellent tutorial..Thanks for posting.

[@Coder-zx4nb]

Fantastic video. I was about to add an air duct to a finished room in my basement and didn't account for return air ducting. Thank god I found this video before I started drywalling my ceiling!

[@ds6491]

I lived in newly built apartments in Florida. They had vents above doors in each room. It worked great equalizing pressure between rooms.

[@britthinkle5715]

Agree...seems to be also a much cheaper solution too

[@ronwalsh]

Had these installed in my Florida home, and it made a world of difference.

[@ArticWolf24]

Thank you for this video. It really did teach me a lot, now its time to redesign my furnace ducting. This video was very informative.

[@dukeofdarkside82]

That was super informative! I'm glad I took the time to watch. I feel that I learned a thing or 2. Thanks for the info!

[@jonasreno3573]

thank you so much... this was so informative.... great job

[@SherrillWoodsJr]

All I can do is share my experience. We upgraded our system and added a game room. We had plenty of return (conditioned air) but the room was 2-3 degrees warmer. We added a "jumper duct" and the room runs about 1 degree cooler than the main room in house. Small cost for amazing result. We did the same in the two bedrooms on West side of house with similar results. Main concern of our AC guy was keeping the supply and return air volume balanced to the HVAC system.

[@ynot6781]

Your ac guy didn't do a load value on your home , typically they don't have the knowledge . Proper load valuation needs some data . Values of the windows , insulation , basically the entire homes r value and cfm per room adjusting every supply as per requirement with the proper sized return . Optimum is high low returns in all rooms which makes it far more comfortable as well as more economical High returns in vaulted ceilings as well

[@Brad.W]

@@ynot6781 Yeah but something like that is out of the question for those of us in manufactured or mobile homes that have zero attic space to run ceiling ducts and vents.

[@elainenilsson5472]

this was really good to listen to. Thank you.

[@five-forty3431]

Excellent explanation, thank you!

[@renatabritoo2]

Nice explanation! Thanks

[@SlingShotNinja]

Yes !!!! Thank you so much

[@01RedSled]

Great info and video. Thank you!

[@connorp8408]

Very informative and well made video

[@aelectriciansebastian4236]

Very professional video. Thank you, this has helped me understand the supply and return theory.

[@DancingSpiderman]

Aelectrician Sebastian Yeah, i also learned valuable info from Larry in this video.

[@craigkennedy9968]

If you bought into this video, you are gonna have aome problems ! This video does nothing to explain duct sizing, duct systems, or airflow principles. It does however show how shady contractors can use a manometer to scam people into unnecessary work they don't need.

[@Guillotines_For_Globalists]

I have seen some homes, especially in Florida, with vent grates added to the door towards the bottom. Serves as a pass through for when the door is shut. Not ideal but a simple solution. Or as someone else said, cut an inch off of the bottom of the door. Probably a more private solution, but either method will serve the same purpose.

[@franny5295]

@Tom Garbo I was actually not taught that but I probably should have. I'll teach my boy. You might have saved a life...

[@kevingordon669]

So that's why that home I was looking at had vents in some of the doors.Thank you

[@j-mobi9209]

Vents of doors are not good for acoustical control and privacy.

[@billymoore9164]

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[@billymoore9164]

@@j-mobi9209 bobbovvvjvujvovjovjjvjvjvjvvjvjvvvvvvvovovovvvvvvvovjvv

[@goosecouple]

Very good

[@Windragon76]

Thank you for the video.

[@richdamico7524]

finally someone talking about the MOST important thing is an AC system, balance and returns , NOT just feed vents, been saying this for 30 years to my friends and family who can get cooling upstairs in older homes. Why don't most HVAC people understand this? Don't they teach basic principles of heat and cold in HVAC school?? AC's are designed to take heat out of the air in homes they do not simply add cool air to homes,

[@porkchop10]

This is great, if you live in the south and have ductwork in the attic. I love in the Midwest, and have never been in a house that didn't run ductwork between the floor joists and basement. Good luck tapping into that without extensive labor

[@cden8718]

Thank you

[@mr.doityourselfandsave4369]

Thanks for the video very professional

[@gmd1417]

Where did you route the jumper ducts to? I wish you had shown that or at least mentioned how you routed the return air from the jumper ducts to the main return that you show at the 1:40 mark of this video...

[@aenimosity7]

Great video, thanks!!

[@jrchicago9216]

Good boy. Nice job.

[@incognitotorpedo42]

To avoid running a jumper duct through a hot attic, I installed a grating near the bedroom floor on the wall between the bedroom and hall. On the hall side, I installed a grating at the top of the wall. The space inside the wall between the studs acts as a plenum. This was code legal for return air when I did it. For this to work, you have to ascertain that there's no blocking in the wall. I also leave bedroom doors open during the day.

[@sukafreecity]

Very,very informative!!!..

[@rockslide4802]

Excellent video. Very informative and helpful. Thank you!

[@SovietUnion848]

Great information!!

[@compulsor5853]

GREAT solution- THANK YOU! For the last 20 years I have asked every HVAC contractor that's been here for service etc. how to improve the air flow of both heat+cooling into the 2 west-facing bedrooms- always told there's NOTHING that can be done; it just seemed wrong. My guess is they either didn't know how, more likely- they just didn't want to put in the time and effort to fix it retroactively,

[@scottwebster7613]

Odds are, they either didn't know, or they didn't see enough money in it to do the job. There is always a solution to heating and cooling issues. You just need to figure out what limits you can set moneywise. Many times, they will shy away from something if they can't do it quickly with easy access. If your duct is hard to access, many small companies don't deal with framing or sheetrock repair. If it is accessible from the basement or attic, someone should have been willing to work with you on the issue. If nothing else, I'm surprised someone didn't try to sell you a one room unit for each room. This would have made someone money and they would have been in and out with minimal fuss or mess. I will attach a link to show what I mean. www.homedepot.com/services/mitsubishi-ductless-mini-split-system/ I hope you find a decent HVAC company that will give you a proper solution.

[@rj.parker]

Return ducts won't help if the rooms are hot or cold with the doors open. Only with the doors closed and then will only give you the same as if the doors were open. Return ducts in zoned systems are useful or extremely large houses OR when the bedroom door is closed and THAT causes temp imbalances.

[@SafeHomes]

Great explaination of this type of system. Thanks

[@aj27781]

excellent video and seems like a very common problems (noise return duct I guess is an indication). Esp. this takes more of an effect when door is closed! (folks in that room have to know what this is about - or would have NO idea on noisy return duct)

[@oldandy1645]

Seems to make sense but still looks like the cool air would blow right back into the extra duct. Our pre-fab came with these new ducts and, based on what is claimed to be good, good for us!

[@videoshomepage]

You can measure the pressure instantly? Great video.

[@danielstewart2251]

Hey Doc, and thanks for the video. I'm in south Florida. The only home I saw w return ducts in rooms was in SC. Now I understand the return ducts in the attic; but how did you attach the 3 new return ducts to the return plenum under the unit in the video? Did you go down the inside of a wall and go through the side of the plenum under the unit where it draws the air from?

[@Demy26]

Great information

[@ericg.magnaye6899]

Great information 👍

[@peterruffo8793]

Easily done on a Ranch house. Problem being when you install in an older home (Cape Cod) you cant always do that type of return. So you can only get returns in certain locations.

[@frankrodriguez7468]

great info....

[@lucasmustang66]

Good video

[@ArtDocHound]

Thanks.

[@voltarsystems]

This is considered old school now. But this really does work.

[@RightToSelfDefense]

I'm not a Heat and Air guy, so I never noticed that a couple bedrooms in my house have no return but the duct but the upstairs room does. I do have ceiling fans in my house and they do help.

[@DancingSpiderman]

I love the detailed explanations that he gives! I'm gonna watch his other videos! Great info, sir.

[@andream3088]

RIGHT! Such a great video. Just wish he would have given an a ballpark on the cost or what to look for during home buying

[@74dartman13]

It always amazes me how poorly heating and a/c sytems are designed. I had a duct cleaning business for many years and I've seen it all...crazy! I have an old house with 2 upstairs bedrooms. Each has a supply vent, but there's only one small return on the floor in one of the bedrooms. Talk about hot in the summer! Gonna install a return higher on the wall of each bedroom. Hope it helps!

[@publicmail2]

So many people don't understand this, so good explanation. I call it a double whammy, air goes out air must come in. It costs big money. I wonder how much inches of WC or pascal you'd have by just putting in a large pass thru vent on doors?

[@1020fender]

Baja 1000 winner Larry Janesky.

[@yacineelyas8756]

The easiest and cheapest way to do the job is to install transfer air grille on the 2 bedroom's doors. Return air escaping from there will be directed to the filter in main return duck.

[@craigkennedy9968]

No, the cheapest and easiest is to cut the bottom of the door to allow for air to pass under it !

[@marctannenbaum672]

The ducts were jumper ducts, and not ducted to the return plenum on the unit. to help balance the pressure differential between the rooms, an opening was cut into the ceiling of the bedrooms and into the central area of the home. Ducts were attached to each of the boots and grills installed. This allows air flow between the rooms to balance out.

[@ynot6781]

In the business they are not called " jumper ducts ". Technically that are referenced as transfer air ducts . Which in this application the home owner could've simply cut 14 by 8 holes above the bedroom doors , installed grills on each side and accomplished the same outcome . But far cheeper for the homeowner

[@docmitchell1]

The gap under the bedroom door is sufficient relative to the floor covering. If the supply to the room is larger than the gap then it may not be enough. If there is carpet (shag), then the gap is too small. Even if the gap is big enough at the time of construction, be aware that somebody might add a thick floor covering years down the road.

[@TXLoneStar_]

Tamarack sells some return register vents that mount on the bottom of the door. Tamtech sells them..google it. Nothing mounted in the attic. What it does is allow more air to flow under the door using it's vents. My Aunt bought 3 of them for her 2 story house. Even the rooms that face west are cooler now than they were before. I'm looking forward to buying them myself.

[@williamdavidwallace3904]

Of course having sufficient return is critical but in houses with finished basements where the intakes are run thru or under the floor it is quite expensive to run new returns. Our current 2 storey house only had 1 return. We managed to add 2 more but doing so in the 2 bedrooms is not cheap at all but could be done I suppose by using the utility shaft that runs to the 3rd floor Running the return duct in the basement would be quite tricky with much removal/replacement of drywall ceiling.

[@booifojoe]

I installed screen doors on all my bedrooms. Worked like a charm.

[@woohunter1]

Automatic Slim perfect!!!

[@jsharkey1786]

Lol

[@freedomisfromtruth]

Keeps the bugs out from which direction?

[@charlesbryant3515]

LOL

[@3beltwesty]

1:04 Almond Carrier refrigerator? Lol . At first sight i said thats my 1970s Almond Sears refrigerator with a Carrier refrigerator magnet!

[@PressurePerfect]

Great info! I live on the bottom floor of a three story condo complex. I don't have an attic to run return ducts to the air handler. The only return duct for my whole condo is at the air handler itself and my bedroom is as far as you can get from the handler. Now I know why it's always more comfortable when I keep my door open at night but sometimes I can't because of privacy reasons. Any suggestions?

[@3beltwesty]

In California my apartment had a return vent right above the door to the 2 bedrooms

[@mmalik23]

I have a main return under the A/C handler. This is where I change my filter. I recently found another return in the hallway of my house & it had a filter as well. I've lived in this house for 10 years from new construction. I was shocked to see that this return box was completely clean with no dust & the filter looked new as well. Is this because this is a jumper box where the bedroom's are connected to?

[@j.morales3166]

I just had a new system installed in my home that wasn't designed for AC so it uses the existing floor vents. 2 story home, the bottom floor is great, the upstairs has 2 rooms that are much warmer. I called the company and said I think I need some returns added to the 2 warmer rooms. They said it wouldn't work but they would love to sell me a mini-split system for another $7k. I'm not a happy camper right now.

[@georgebaird2366]

You have to connect return ducts in attic like the supply which means you have to go in attic to change filter instead of main filter return grill and ducts in attic are almost doubled better under cut doors 3/4 inch or return transfer grills

[@MrMed-hl2fq]

thanks - never knew that before. I have 2 returns in a 6 room house.. guess i'm out of balance too...

[@ynot6781]

Basic rule of thumb , you want to return as much as you supply For 10 supplies , you want 10 returns .

[@jeffreydektor2429]

After reading the comments, I think many are a little off base. This video, in my opinion, was a demonstration of how the return air pathways improved à pressurization problem and was not a “how to DIY”. The explanations made perfect sense.

[@BTC909]

It would seem you need to keep your return ducts as far away from your conditioned air ducts as possible. Also if you have an older home and generally the conditioned air duct isn't installed in the center of a window or between a set of windows you would be advised to move the conditioned air duct if possible. Yes you run into the issue with filling a hole and whatever texture is on the ceiling. You can also use an adjustable return air vent (with the room door closed) and measure the temperature of the room and restrict the return air flow to achieve the best lower air temp.

[@kevinleecaster2698]

Restricting airflow not 'good ' approach

[@justintime8176]

Im installing a concealed duct mini split system in my attic. Its labeled as a low static unit. Is there a sizing formula for supplies to returns per room?

[@dagestanifive]

I hope those new returns are filter grilles... all the dust from the other rooms will bypass the filter at the main return and make your evap coil filthy since they are probably all on flex lines that tie directly into a return plenum so you'll get "balanced" air return but get to breath in all your dirt and dust over and over again. i have been an HVAC contractor for many years

[@supaman881]

The video is labeled installing jumper ducts but no one watched him "Install" jumper ducts. The only thing they saw was a register vent cut into the ceiling. For the ones that don't know, He simply cut roughly a 10x10 register inside the bedroom and a 10x10 register in the hallway and conected the two with duct work to allow the Main return in the house to pull air out of those rooms while the doors were closed. The same thing can be achieved by cutting about 1 1/2 inches off the bottom of the door, Cutting a fancy register in the bottom of the door or above the door. To test this, turn on your Airhandler and crack your bedroom door, hold your hand up to the crack and feel the pressure of the air being drawn. The above methods does the same with the door closed. I hope my comment helped someone understand this poorely made video that left some people scratching their head.

[@Migkiller1971]

I have a two story home in Parker, Colorado. The main living area (lower) and the Master Bedroom is wonderful but the other three bedrooms are warm in the summer (Tstat at 74) and cold in the winter. my kids keep the door closed. The 3 bedrooms are above the three car garage which is hot in the summer and cool in the winter. I thought maybe that was the problem. Interesting

[@machinemanbaltimore]

Nice video! Now I know!

[@garyfe5065]

You explained everything I’m been googling that last two summers. Ty sir

[@dogsareawomansbestfriend]

I wish you could figure out my house to make it comfortable in the winter!

[@trinkladd]

Question. Would the return suck the cool air flowing from the vent? Curious trying to design ductwork for my house.

[@rodgraff1782]

The proper term is transfer grilles. What comes in must be able to get out, otherwise there is no movement. Be it transfer grilles or under cut odors. Doesn’t matter. Supplies should be directed toward the areas of greatest heat loss, such as windows. Returns should be positioned to return the air after the supply air properly mixes with the air in the conditioned space.

[@jonathanschulz5841]

What do you think the open face surface area of those return duct registers were? I would be curious to see if you could get the same results by undercutting the doors an extra inch.

[@kens97sto171]

Trim the bottom of the doors off about 2 inches. Especially with the air source at the ceiling. Mobile homes do it this way to eliminate need of a return system. Also mini split systems if your replacing a system is a good solution. Heating and cooling the air directly in the room rather than moving cooled or heated air around through ductwork.

[@valerief1231]

I like the mini-split system idea, I think o need to research that. Our home is super weird with the HVAC system. It's horrible, and we need to do something besides cut holes in the ceiling. Thanks for the idea!

[@jermcee]

Most of the air actually returns underneath the door. You can feel it if you stand outside your door without shoes.

[@OMGAnotherday]

✌️Yeah positive pressure escapes wherever it can!

[@keithhoward8651]

I kind of new at hvac but I was wondering what kind of meter you were using in this video

[@paulsantangelo3813]

Hi there: Thank you for this, but you really didnt go i to how you added the return ducts. You cant just dump all 3 returns in the main return box did you? I would think by the title that you dumped the 3 returns onto a separate box and then connected that box to the main return, is that correct? Thank you

[@notsure3331]

awesome video thank you for making that video but I have a question do you operate in Minnesota and if so what does it cost to have somebody like you service a house and see what's going on I have one intake duct for my furnace and it's in the first floor I have two Floors Plus basement my house sucks in the winter it's cold drafty and I do plastic the windows and my home is still really drafty in random spots it's an old house cannot figure out how to run ductwork upstairs for intake in other words I don't know how to do it what would something like that cost just curious

[@TransplantHelper]

Will it help to put vents in the doors to allow return air to pass when they are closed. I’m sure it’s not the best solution but will it help? Awesome information, great video

[@ynot6781]

Yes , but then your jacking your doors with a big grill , just cut off the bottom of the doors so there is a 3/4 inch gap between the floor and door . Or just cut through the drywall above the doorways and install return grills on each side , 10 by 6 grills are fine .

[@tracienewham1987]

Can i ask you a question i live in a home that has floor vents central heat and air paid out the ying yang for it it is always hot like 89 in summer and constantly getting air fixed but i do have vents in every room at top of house but we closed them off because when open it is so hot because of ten roof and attic was wondering if we should open them or what is the purpose of them when there has never been anything but floor air there was a fireplace when i was first buying but i had it removed so i just figured it was for them

[@ynot6781]

Ok , let's start off with the inferior duct system in the home . The supplies are mounted incorrectly in the middle of the room . Supply air is to be on the load walls , the outside unconditioned walls . The return air should yes be in each room however they should be high low installed in the walls and tied directly into the proper sized return air duct . In the summer you would open the upper returns to pull the hot air off the ceiling and the cool air up off the floor into the living space . In the winter the reverse , close the top return grill which allows you to now pull the cold air off the floor and the hot air you just spent money heating off the ceiling and into the living space . The return in the bedroom is to close to the supply , optimum would be the supply at window and return by the door . Which he could've done , he could've used the existing supply hole for the return and cut a proper supply in the ceiling close to the outside wall . Yep it's more money but more efficient . Since this is a cheep fix video , the home owner can go by some 14 by 8 grills at home depot , and cut transfer grills above their doorway trim . Simply cut a hole through the drywall and mount a grill on both sides , now the air can be transferred into the hallway where the central return is . If you have four bedrooms it's going to take 8 grills , some screws....supplied with grill , a philips screwdriver , drywall saw , about 80 bucks and two hours of your time and basically accomplish the exact same thing . Cheeper yet is undercut the doors

[@CoroaEntertainment]

With homes without properly placed return vents, simply removing/cutting off about 1/2" to 1" from the bottom of the door for each "problem" room (so there's more space between the bottom of the door and wood floor/carpet) should be enough. Example, for a 32" wide door you would have an extra 16 to 32 square inches of space/ventilation to work with. It's also a lot quicker (and cheaper) than cutting a hole in the ceiling of each room to install a jumper duct. The main problem with ceiling jumper ducts, is when it's cold outside. A ceiling jumper duct would allow the heat from the furnace (that is used to keep that particular room warm) to simply exit out of the room and eventually out through the roof vents (when the furnace is running), and cold from the attic to easily enter into each room (when the furnace is off). Not a good thing if your city/state gets cold during the winter season. It would also increase the yearly costs of heating your home. In Canada and Europe, home builders are staring to put return vents at both the top and bottom (on the wall) of rooms/living spaces. Doing so allows for better and more efficient return air flow adjustments during the summer and winter months. Example, during winter/cold months, the top vent would be closed (bottom vent open) to help keep warm air in the room (remember, warm air rises).... and during summer months, the top vent would be opened (bottom vent closed) to help keep the room cooler in the summer. If the home you live in has a wall mounted vent (top or bottom), you might be able to add the opposite vent as well (as long as the wall cavity doesn't have a horizontal block of wood in that space), thus allowing you to adjust return airflow to help make your home more efficient during the summer and winter seasons.

[@valerief1231]

So I am curious, what is the difference of the forced air being pushed out thru the window seals etc. and the conditioned air going into the attic. I get what you mean about the pressure, and flow improving, where I got lost is how does feeding the air into a hot attic reduce energy costs? And with the jump ducts, are they insulated to keep the hot attic air out of the bedrooms?

[@chiujuno]

Great videos Larry. Questions 1. What size duct you used for those bedrooms return and how do you calculate it. 2. What device that you used to test the pressure. Thanks

[@OlGoodJoe]

It really depends on how much return (lower pa) you are aiming for. Adding the same size duct in sq inches as the supply air duct will normally do the job. What you are trying to do is 'break' the pressure so some or most of the air can return back to the common space.

[@joep43]

Bless

[@emjavaldez26]

Can u show us how u connect these ducts in the attic .

[@laroka69]

This has got to be one of the best, if not the best, informative video on AC issue.

[@inquisitvem6723]

Can you do a video on how to insulate the attic? i heard there is a machine to rent that you spray insulation.

[@Methodical2]

I learned from our built home that next time I will be smarter when it comes to the HVAC system. We were going to jumper the return in the upstairs bedroom, but found out the top return sat under a ceiling joist.

[@patrickkelleher2309]

Careful, It can be surprising how much a negative draw can alter the entire system

[@Methodical2]

@@patrickkelleher2309 If I ever build a house again, I plan to sit down with the HVAC folks myself and go over the type of system I want and my goals.