Your home’s HVAC system is truly an unsung hero: Working at all hours by drawing in air from inside your home, filtering it, and then heating or cooling it before sending it back out to keep you comfy.
But where exactly does your HVAC system pull its air from? And how does this seemingly small detail impact the overall climate and comfort of your living space?
In this article, I’m going to dive deep into the world of return air vents. These components might not always be in the spotlight, but they play a huge role in your HVAC system’s efficiency and your home’s air quality
I’ll explore where return air vents are located, their crucial role in your home, and answer some common questions – like whether it’s a good idea to block a return air vent and what really sets apart an air vent register from a grille.
Understanding the Role of Return Air Vents
Return air vents are integral to maintaining a comfortable and healthy environment in your home. In the section below, I’ll dive into the functions of return air vents and how they contribute to your home’s overall comfort.
The Basic Functions of Return Air Vents
- Circulate Air: The primary role of return air vents is to facilitate air circulation throughout your home. They draw in the indoor air and send it back to the HVAC system for heating or cooling, ensuring consistent temperature regulation.
- Maintain Air Pressure: Return air vents help maintain a balanced air pressure within your home by continuously cycling air. This balance is crucial to prevent issues like air drafts or stagnant air, which can occur when air pressure is uneven.
How Return Air Vents Affect Indoor Air Quality
Beyond temperature control, return air vents help improve air quality. If a return air vent is equipped with a filter, it effectively captures dust, pollen, pet dander, and other airborne particles. This is especially beneficial for individuals with allergies or respiratory issues.
Additionally, by facilitating air circulation, return air vents help reduce moisture levels in your home, decreasing the risk of mold and mildew growth.
How Return Air Vents Contribute to Energy Efficiency
- Optimize HVAC Performance: Properly functioning return air vents allow your HVAC system to operate more efficiently. When air is evenly distributed and cycled through your HVAC system, it reduces the workload on your HVAC unit, leading to energy savings and potentially lowering your utility bills.
- Prevent HVAC Overload: Blocked or poorly maintained return vents can lead to an overworked HVAC system, reducing its efficiency and lifespan.
How Return Air Vent Location Impacts Your Home
The location of air return vents in your home plays a pivotal role in the efficiency and effectiveness of your HVAC system. Understanding this placement can significantly improve your home’s climate control and overall comfort. Here’s what you need to know:
Variations in Older and Newer Homes
- Older Homes (Pre-1990s): Typically, older homes have a central air return vent system. This usually consists of one large vent located in a common area, such as a hallway or living room. The central placement was primarily driven by construction norms and cost considerations of the time, rather than energy efficiency.
- Newer Homes: Modern home designs have evolved to include multiple smaller air return vents. These are strategically placed in various rooms like bedrooms, living areas, and even kitchens. This distributed approach helps in better air circulation and temperature regulation throughout the home.
How Return Air Vent Location Impacts HVAC Efficiency
- Centralized vs. Distributed Vents: While a single, large central vent can effectively circulate air in smaller homes or those with open floor plans, it may not suffice for larger or multi-story homes. In contrast, multiple smaller vents in newer homes allow for more uniform air distribution and temperature control, possibly enhancing overall HVAC efficiency.
- Location Considerations: The specific location of air return vents can be influenced by the layout of the ductwork. For instance, vents might be placed in the ceiling if the ductwork runs through the attic, providing a direct path for air circulation. Similarly, in two-story homes, having return vents on both floors can ensure efficient air movement and temperature regulation.
How Return Air Vents Affect Home Comfort
- Room Usage and Vent Placement: The functionality of each room should influence the placement of return vents. For example, bedrooms and living spaces, where consistent temperatures are desired, benefit from having their own return vents.
- Avoiding Hot and Cold Spots: Properly placed return vents help in avoiding hot or cold spots within the home. This is crucial for maintaining a comfortable living environment, especially in areas with extreme weather conditions.
How to Identify Return Air Vents
So you’ve found an air vent in your home, but how do you confirm whether it’s a return vent or a supply vent?
Air return vents are designed to draw air into the HVAC system for heating or cooling. Unlike supply vents that blow conditioned air out, return vents pull air in. This key function sets them apart and is vital for maintaining the system’s efficiency.
Here are some ways to identify them:
- Appearance: Return vents are usually larger than supply vents and often lack adjustable louvers. They typically feature a grille design and are strategically placed either on the wall or ceiling, depending on your home’s layout and the HVAC system design.
- Location: Commonly, return vents are located in central areas like hallways or larger common rooms. However, in newer homes, you might find them in individual rooms for better air circulation.
Simple Tests for Confirmation
If you’re still unsure whether a vent is a return or supply, there are a couple of simple tests you can do:
- The Paper Test: Hold a piece of lightweight paper or tissue near the vent while the system is running. If the paper gets sucked towards the vent, it’s a return vent. If it blows away, it’s a supply vent.
- The Incense Stick Test: Light a small incense stick and hold it near the vent while the HVAC system is operating. If the smoke is drawn towards the vent, it indicates that the vent is pulling air in, confirming it as a return vent.
Air Vent Registers Versus Grilles: What’s the Difference?
When it comes to air vent registers and air vent grilles, you might have heard these two terms used interchangeably. While they are similar, they are actually two different things:
- Air Vent Registers: These are typically found on supply vents, where conditioned air is blown out into the room. Registers come with adjustable louvers (slats) that allow you to control the direction and flow of the air. They often have a lever or a knob to adjust the louvers to direct airflow.
- Air Vent Grilles: Grilles, on the other hand, are used on return air vents. Unlike registers, they do not have adjustable louvers. Grilles are designed with fixed slats and serve primarily to cover the duct opening, preventing large objects from entering the HVAC system while allowing air to be drawn back into the system efficiently.
Another type of air vent device is the air vent diffuser. Diffusers are similar to air vent registers, but they are non-adjustable.
While registers allow you to direct airflow in a certain direction, diffusers disperse air in all directions.
Debunking Myths: The Truth About Return Air Vents
Misconceptions about return air vents can lead to common mistakes in their usage and maintenance. In this section, I’ll clear up some common questions about return air vents.
Is It OK to Block a Return Air Vent?
A prevalent myth is that blocking return vents in unused rooms can save on energy costs. However, this is not the case. You should never block a return air vent.
Blocking a return air vent disrupts the air pressure and flow within the HVAC system, leading to inefficiencies and potentially higher energy costs.
Blocking return air vents in your HVAC system can lead to air leaks due to high pressure differences in the ductwork, potentially causing duct implosion.
This air blockage also risks the HVAC unit itself, as insufficient airflow can damage an air conditioner unit by causing pressure imbalances. Similarly, a furnace with inadequate airflow can experience issues like tripping on high limit or a cracked heat exchanger.
Is It OK to Close Off a Return Air Vent?
Some believe that closing off return vents in certain areas can enhance the system’s performance in heating or cooling other parts of the home. In reality, closing off a return vent can strain the HVAC system, leading to uneven temperature distribution and potential long-term damage.
Too much return air is never a bad thing. So there’s no reason to choke or dampen a return vent.
What’s Next?
Hey there! I hope this guide has shed some light on the ins and outs of return air vents and how crucial they are for your home’s comfort and your HVAC system’s efficiency.
If there’s anything that’s still a bit fuzzy or if you have a question about return air vents, don’t hesitate to drop a comment below!
Good day and thank you for the article. I have a question regarding changing the pressure in my return vent system. We have a 60 year old, 1 1/2 floor home with a poorly installed furnace in the basement. (I believe) our biggest problem is circulation of air. We have no return vent on the upper floor and half the vents on the main have very little flow. I suspect this is because our furnace in directly under two of them and those two are doing all the work. How can I change the pressure in my vents to increase suction at the far end of house (35′)? My return vents are “boxed in rafter” style, not pipe. Thank you greatly for any help, our small town professionals are terrible 🙁
Cheers
Jeremy
Hi Jeremy,
That sounds like a complicated issue. I recommend finding a company that specializes in air balancing to look at your system.
Hope this helps,
-Trey
Can I cover 4 inches on the side of my return air vent with a refrigerator?
Hi Jamie,
That’s not a good idea, it will restrict return airflow to your unit.
-Trey
My returns are in the 2nd floor ceiling. Seem fine but in winter I can feel cold air seeping in if I walk or stand under it. Means I’m wasting energy heating colder air from the attic that is making its way into the home.. is there a fix for this? Or is it just poorly designed
Thanks!!
Hi Scott,
I’m assuming the central air system connected to your return vent is off during the winter. If you’re feeling cold air seep into your home through the return vent, you could have a leaky duct somewhere in the attic.
Hope this helps,
-Trey
Hello,
How do I quiet a very noisy return vent? Thanks.
KS
Hi Kimberly,
Return vents make noise due to the velocity of the air passing through the vent. The “quick and dirty” fix would be to bend the fins on the return vent to allow more air to pass through the vent unrestricted. I’ve seen this trick work a few times, but not always.
Another way to fix a noisy return vent is to swap out the vent grille for one with less restriction. Try finding a grille with more open space for air to pass through.
Hope this helps,
-Trey
Hi Trey,
I replaced my old HVAC in my attic with a high efficiency system. At that time, I had one return air vent (20″ x 25″ x 1″ filter) in the hallway of my 1 story, 2078 sq. ft. house. The installer recommended that I install another return air vent. The second return vent was installed in a tiny 9′ x 7′ room. I notice that the filter that room stays clean for months while the one in the hallway must be replaced monthly. My kitchen, dining room and family room are in an open open area (approx. 800 sq. ft.). I think the second return vent should have been installed in that larger central area to improve the air quality and circulation efficiency. Am I wrong about this?
Thanking you in advance :-)!
SG
Hi Sandra,
Does the tiny room see much traffic? If the tiny room doesn’t get much use that could explain why the filter stays clean.
As for the placement of the second return vent, there might be a good reason why the installer put it in that location. I would contact the installer to clarify what their logic was to put it in the tiny room.
Hope this helps,
-Trey
Hello Trey,
I have one return vent placed high and located in the main living area of a 832 sq ft home with a partial basement + Crawlspace. Gas furnace is a downflow to basement. My issue is that when the furnace runs it’s pulling cold air out of any nook and cranny it can find in this old house, and I’m working on those. I weatherstripped the bedroom and bath doors to stop some of this and now those rooms are warmer, but can always feel a chill in the main area. Do I need another return vent? Cool air gets pulled up from the basement and past an old back door as well. I finally figured out what’s going on and it’s driving me nuts quite frankly. Is it bad to have sealed those rooms, pressure-wise? Return vent is 14×20. Thanks in advance!
Hi Dawn,
Yeah you might need more return air. I would get an HVAC company to measure system’s airflows.
Hope this helps,
-Trey
Hi Trey,
Great information in this article. I have had havc guys to my house to fix my issue. All of them give me a different answer and want a lot of $ to replace what seems to be working. All of my research says you have the most logical answer for my issue. I have about a 2,000 sq ft on my first floor. Furnace is in the attic with flexible ducts. I am told there are no leaks in the ducts. 9 or 10 registers, good size, 1 large 20″ x 30″ grill return in an open hallway in the middle of the downstairs, with the filter changed often enough and I am now using a #5 filter instead of #10. Air flow is great to the farthest register from the furnace. As I feel the air going in other rooms closer to the furnace the flow drops off and even drops off more as the heater is run for a longer amount of time. It takes way to long to heat up my downstairs. Is my issue needing to add another return and how do I make sure it is put in the correct place to have the most efficiency? I don’t trust the havc guys.
~Lynn
Hi Lynn,
I would call an air balancing specialist to give a second opinion.
Hope this helps,
-Trey
The only return air vent in my upstairs is near the ceiling. It was installed there to pull the hot air from the ceiling in the summer when the AC is running. I have been covering it during the winter to keep from pulling out any warm air. My problem is that my upstairs is cold and I can feel the coolness halfway up the stairs when going up. Am I wrong in covering the vent in the winter time? My HVAC equipment is all in the basement.
Hi Judith,
Don’t cover the return vent at any time. If you cover the return vent, it will cause huge problems in your system, regardless if its heating or cooling.
This article is so helpful. Thank you.
I have a big machine (the furnace?) next to an outside wall. It is designed to handle ducts in 6 areas but only 4 were ever installed. Long story. This was over 10 years ago.
Is there any financial value in replacing the machine for a smaller one?
I am still trying to understand why I have to have a/c on in three rooms and I have no idea which is the one room that was chosen as the one which must always be on when I use the system. Would appreciate some help.
Hi Heather,
It’s hard to tell without seeing your system, but most systems are designed to cool the entire home – so I’m guessing that’s why you need to have the AC cooling all your rooms.
Restricting the airflow to one or more rooms is bad for your unit and will cause problems in the long run.
If you want to replace your machine, I recommend getting a local HVAC contractor to take a look at your system and make recommendations.
-Trey
Hi!
My air return vents – 2 on the top floor (hallway, and ceiling in a bedroom), 1 on the main floor, 1 in the basement – omit a foul odor, sort of like rotting garbage. The odor is intermittent – smells for a day, goes away for a few days, comes back stronger for a few days. It also seems to be worse when we run plumbing and hot water (dishwasher and washing machine). For context, we recently took possession of the house, and this odor started about 2 months after that. We had our air ducts cleaned, and that helped for a few weeks, but the odor has come back. Any ideas on what could be causing the issue?
Hi Elena,
The first thing that pops into my head is a dead critter. Are you sure it’s coming from the return vents?
Thanks for replying. The smell is definitely the strongest near the air return vent in the upstairs hallway and the one on the main floor.
Trey, thanks for taking our questions. I have a wide vent (30″ or so)in my living/den area but it does not feed into a return air duct that I can tell. It stradles a wall stud. Each bedroom has a return air. also there is no return air duct in the upstairs bedroom. Should this vent feed into a duct for return?
Thanks
Ron
Hi Ron,
I would get a local professional to get their eyes on the system and check if the positions of those vents are okay.
-Trey
Hi! I just bought a house and when I removed the filter for the return to replace it, I noticed that there is no metal duct work, the opening is just the space between the studs and drywall? Is that OK, shouldn’t it be actual metal duct? Thanks….
Hi Matthew,
Yeah, that type of return is a cavity return and it’s used in some homes. If there is a filter rack at your air handler it might be wise to use a filter there instead. Dust can sometimes find its way to your unit from the cavity since it’s not the cleanest space and is prone to air leakage.
-Trey
My home is approximately 1500 square feet, built around 1978. . I have one return ac duct in an open area that I would like to close in to make into a separate room. Does the return duct need to be open to the entire house or can it be inside an enclosed room?
Hi Kathy,
The return vent can not be inside an enclosed room. If the return vent is inside an enclosed space it will fight to get airflow and cause issues with your system. If you want to make the area where the return vent is into an enclosed room, you will need to have the return vent relocated to an open area.
Hope this helps,
-Trey
This is a great article and the question/answers are super helpful. I did not see anything about particular types of return air vent covers (grilles?). I want to use the routered wood or MDF versions that you can paint in your wall colour, but our HVAC company doesn’t think the air flow is good enough. The manufacturers of these grilles don’t specify the airflow percentage. Are they really lesser than? I really don’t want metal grilles, but I don’t want to restrict air flow either.
Hi Wendy,
Yeah, I’ve been getting lots of questions regarding grilles recently so I’m working on adding a section that covers them.
I agree with your HVAC company – most of the wood and MDF grilles I’ve seen look like they restrict more airflow than the metal grilles due to the size of the slots. I don’t have any statistics to back that up, though.
Have you thought about painting a metal grille instead? I recommend checking out some fixed bar grilles since they provide good airflow and look okay in my opinion.
Hope this helps,
-Trey
I appreciate it. I’ll look into an alternative.
Thank you!
Hi Trey, we recently replaced a closet door where the AC intake is in our son’s condo (950 sf). The previous bifold door had slots where the new doors are sliders-to allow us better access to additional space next to the AC. They are not heavy slider doors. Bad idea? Thanks for your help!
Hi Marina,
You need to ensure that there is a path for airflow to the return vent. I’m not sure exactly what your new door looks like, but you might need to leave the slider open to allow for return airflow.
Hope this helps,
-Trey
Hi Trey,
After I finished my basement, the suction from the return in bedrooms on the 2nd floor away from the master bedrooms has become very poor. This problem becomes very noticeable in the summer months when these bedrooms fail to cool. Perhaps is it not so much of an issue in the winter since hot air naturally rises from the first floor. Note that the master bedroom is fine. I called a heating-cooling tech to inspect and he could not diagnose without opening up the ceiling in the basement, so we did not go that route. I also tried a cleaning service to clean the ducts but they could not find any block either, but not sure how thoroughly they checked as they were there to clean the duct. Any suggestions on how to diagnose/remedy the problem?
Hi George,
It sounds like your basement was added to your HVAC system. Assuming that your HVAC system is large enough to accomodate the new zone, you will need to get your airflows rebalanced.
Hope this helps,
-Trey
I have a main room with two return vents, one in the floor that does not seem to blow any air and one near the floor on the wall that does blow air. Is it necessary to have two? There is no place to put furniture. Can the one on the floor be covered?
Hi Dorothy,
I don’t recommend covering any vents unless you have an HVAC professional take a closer look at your system determine that its ok.
-Trey
I live in a condo built in the late1980s. There are two cold air returns in the condo. They are both next to the furnace closet. One is baseboard level and one is above at ceiling level. Should i do the seasonal close of one or the other as our tempature is not consistent
Hi Marilyn,
Are you sure that those are both returns? Either way, its probably not necessary to close one of them.
-Trey
Hi Trey: I live in a split level and the lower level is unfinished, but the air conditioning/heater unit has a return air duct installed that is blocked off but there is a note on it that says future bathroom of which I just built. That duct is very close to the bathroom wall and I’m not sure how to connect from that duct to the vent grill. Can I use flex hose to connect between the deck and the grill? Thank you.
Hi Dave,
Flex duct isn’t usually recommended for returns since dust tends to build up between the spirals inside the duct. If you use flex duct, put a filter at the return air intake in the bathroom. A better solution would be to get a rigid sheet metal duct installed.
Hope this helps,
-Trey
Hi Trey, I have a 1200 sq ft one level home built in 2021. The furnace is in the attic and the HVAC installer placed the return air vent directly below it. It is extremely loud when with the AC or the Heat is on. I’ve read several articles that dissuade this, but I’d appreciate your opinion. Also, the builder refused to put a duct opening in the Master Bathroom and fairly large Master Closet. Whenever the temperatures are extreme, I have to leave the door open to the closet. Is this common?
Hi Cindy,
Yeah – generally speaking, the closer that the return vent is to the unit, the more noise it will make.
Having no supply vent in closets and bathrooms is not uncommon – especially if they are not connected to any exterior walls.
Hope this helps.
-Trey
Thank you for replying. The Master Bath has one exterior wall and Master Closet has two exterior walls. Is it efficient to install the return air vent on the ceiling, immediately below the furnace?
Cindy
Hi Trey,
Earlier this week I had someone come and do a tuneup and check up on my air conditioning system. Everything was a OK but to my horror when I get home this evening my husband had placed an Amazon box that actually hadfurnace filters in it against the cold air return. it had been there for approximately four hours. There is no possibility of damage is there? Thank you.
Hi Jennifer,
If your AC hasn’t shown any problems from blocking the cold air return for a few hours, it’s probably going to be fine.
-Trey
Hello Trey-
I recently painted a basement ceiling (it is drywall/finished) and removed the return air grille in the process. To my surprise, it was not attached to a return air system, just open ceiling. Would this be appropriate for a basement setting? Also, now I need to reinstall the grille on the ceiling and did not take note as to which way the slotted vanes should point. Should they face the adjacent wall or the room?
Hi Jean,
It’s hard to tell without seeing your exact installation, but that type of return vent is not uncommon.
The grille should face whichever way will obstruct your view from seeing into the plenum. It doesn’t really direct air.
Hope this helps,
-Trey
Hello,
Question please: Our home which was built in 1965 has two areas about 12 inches tall under closets where I believe return air is collected. My question is are there ducts under the slab were the air is returned to the A/C unit in the garage?
The reason I ask is there is a wall behind the door of my bedroom and one of those areas. If I cut a hole right above where the base board is would that act as a return vent for my bedroom? My bedroom is on the west side of our house and can get really uncomfortable even though it is 70 degrees in the room which is within a degree or two of what the thermostat show in the hall right outside my door. I was thinking about cutting the hole about the side of the supply vent in the ceiling and using one of those adjustable supply vents so I could turn it off in the winter time if it got drafty or cold in the room in the winter time. Any information would be appreciated.
Sincerely,
Mark
Hi Mark,
That’s a very specific question, I recommend having a professional take a look at your system so they can make recommendations.
-Trey
Howdy Trey,
I have been noticing water collecting and draining into a pipe periodically in my return air compartment. We have been in the triple digits here in Texas and humidity is always an issue here in the Brazos Valley. Should I try and soak up some of that water? Also, I need to replace the liner material that is in the compartment, but I don’t know what to buy. It almost feels like a thick felt-type material, but I’m not sure.
Hi Toni,
It sounds like you have a minor clog in your condensate drain system. You shouldn’t need to soak up the water, the AC should drain water by itself through the drain pipe without your help. You should clear out your drain line. Here is an article that I wrote regarding clogs in AC condensate drain lines: https://hvactrainingshop.com/ac-condensate-drain-line-clogged/
The liner material in the cabinet is insulation. I’m not sure exactly what kind of insulation your unit currently has. But if you want to replace it yourself, one thing you can try is duct board insulation. However, I recommend hiring a professional to replace the insulation since it can be a tough job and you run the risk of making your unit’s condensation problems even worse if not done correctly.
-Trey
Thank you for your reply. I live in a multi unit condominium complex. I am not sure where to look for the external drain, but I will check out the drain in my unit. My cabinet is 10″x20″ in regard to the insulation. The insulation just seems to be glued to the shelf. It is old (probably the original 1978 install). I think it would be simply enough to replace, but if an HVAC expert needs to be called, I will do that.
Hey Trey
I had a central air unit put it but it does hold the temperature at the set temp (I.e. set for 73 but house temp will get to 80) so the unit runs constantly without shutting off (not good for my electric bill) after several service calls I’ve been told I need to have my return vent moved higher on the wall currently in a hallway with placement low to the ground. Is this an valid solution to my issue ?
Hi Cheryl,
That’s a complicated issue. I recommend getting a second opinion from a different company.
-Trey
Just want to tell you I appreciate you doing these articles. You have answered so many question for me. Getting the right terminology so I can explain to someone else what I mean and helping me understand how the units work.
New build, three floors, 1750sqft. Thermostat for central air set at 73F = 68F floor 1, 73F floor 2, 78F floor 3. All rooms that don’t have returns have transfer vents. Return flow sounds & feels greatest on floor 1, a bit less but still good on floor 2, and almost non-existent on floor 3. Is there any DIY way to boost return on floor 3 (assuming that this will make a difference in cooled air distribution)? Thanks!
Hi Joseph,
Do your returns have dampers? That would be the best way to balance out the return airflow between the 3 floors.
-Trey
Hi Trey. You’ve been so good at answering others, I thought I’d give this a try. I have a fly issue. I get flies in my home during the summer when the a/c unit runs. When it doesn’t run a lot, I may see one or two. But when it runs, here they come. I’m talking one after the other. Sometimes 3 or 4 at a time. I suspect there’s a correlation between the ductwork in the house and the a/c. My unit is an older one (12 years at least) and on ground level on the side of my house. I do have a finished basement where the entire hvac system lives, on the same side of the house. There are vents in the basement as well. And yes, flies are down there also. But I can’t visually see any gaps or holes on the outside unit or pipe leading into the home. Or could they be coming in through roof vents? I’m at a loss. I don’t know how hvac systems and ventilation systems are put together but I’ve been trying to troubleshoot on my own. I’d appreciate any ideas you may have. This has been going on since I moved here five years ago.
Hi Antoinette,
Do you know if you have an outside air intake vent? That would be the first thing I would check.
-Trey
Our home was built in 79, I’m not sure how we past inspection but come to find out the flippers removed the return ducts. Been rolling without them for 3 years, how important is it that I have those installed?
Very important that you have those installed. Consult with a local HVAC professional to have a look at your home.
Hi Trey ,
we have an early 70s style home w/ the return vents close to the floor . Wouldnt it help efficiency top have them close to the ceiling to pull out the rising hot air ?
Hi Bryan,
In an ideal world, putting the return vent near the ceiling would be ideal for cooling your home, since hot air rises.
But if you live in an area that is dominated by the heating season (for example, anywhere in the northern US), then the opposite is true – you’d want the return vent near the floor.
However, there are other things that outweigh the impact of the height that the return vent is placed.
For example, the size and shape of the home will dictate the location of the return vent – many homes are designed in such a way that dictates where the return vent is placed without any regard for the height of the vent.
One thing that’s arguably more important than the height that the return vent is placed is the location of the return vent in relation to the supply vent. Ideally, you want your supply and return vents placed as far away from each other as possible so that the air in your home is sufficiently mixed, and the air from your supply doesn’t just get sucked right back into the return.
There are many things that take precedence over the height of the return vent, these are just a few.
Hope this helps,
-Trey
Mr. Lewis, I live here on Tresure Coast in Florida. My 2200 sq. ft. home was built in 2005 and the HVAC and duct work (flex) were replaced in 2014 by previous owners. I purchased the home in 2015. The AC unit is outside, and the air handler is in the garage. The flex duct work is in the attic. All the ac vents are in the ceilings. The air return vent to the air handler is at floor level in the hallway next to the garage where air handler is located.
It was noted during the home inspection before I purchased the house that the air return vents in the ceiling in the master bedroom, (west side of house), the hallway (east side of house) and two bedrooms (east side of house) all had insulated foam board underneath the vent covers. The return air vents from these rooms are connected by duct work to a ceiling return air vent (also covered) above the floor level return air for the air handler.
When I asked the previous homeowner why they were covered he stated that during the year when it was over 95+ degrees in the attic you could feel the hot air coming out of the return air vents so he, not the HVAC installers, blocked them off.
Basically, the only air return to the air handler is the floor level 24″ x 24″ main air filter vent to the air handler.
Should I remove the foam panels from the air return vents in the other rooms. Seems like having them in place would affect the air balance of the system.
Thank you.
Hi Mike,
Generally, blocking return air vents is not a good idea. Sounds like the previous homeowner didn’t directly address why he could feel hot air coming out of the attic, he just provided a bandaid instead of a real solution.
Removing the foam panels is a good start, then you can see for yourself where the hot air is coming from and get an HVAC professional to address the real issue.
-Trey
I have a air return on my door entrance (on the bottom of the wall) and that is the only place can fit my shoe cabinet. I know you said should not block the vent. Is that okay to just leave a gap in between?
Thanks you
Hi Coral,
Is that the only return air vent in your home? If that’s the only one, then you should not block the vent at all.
-Trey
Good Morning!
I just had a new central air installed (a Goodman, 3 ton). It is the same size as the old unit. The unit blows air up into 3 rooms of the house, and it works fine. There are also a couple vents that blow down into 2 rooms and a hallway. There is very little air coming out of those vents. With the old unit, you had a nice “breeze” blowing out. The tubes for these vents run in the Return down to the basement. I’ve had the HVAC guys out 4 times to look at the air flow. They find nothing wrong. Last week’s 90 degree days saw my temp upstairs not drop below 79 degrees (set at 72, thermostat is upstairs) Again, old unit worked fine. My question, which may be hard to answer, is: could the tubes running in the return “NOT” be hooked back up where they need to be? Could that be my problem and how do I go about checking that out? Or is the air handler just not pushing the air out as well as the old system, you know, “not made the way they used to be”? And this is what I’m stuck with.
Thanks! Great article/ info by the way!!!
Hi George,
My first inclination is that your system needs to get its airflows measured and balanced. Then adjustments can be made to the blower in your new unit if needed.
Hope this helps,
-Trey
I have a Rev Cycle Air Conditioning ducted) installed in a 3 beddy. The return air grill is placed in the middle of the hallway where we have 3 bedroom doors, 1 laundry, 1 bath doors. When the RCAC runs, it sucks outside cold air through the bottom gaps of laundry n bathroom doors. It still feels the suction pulls on the bedroom doors as well. Should I open a bedroom door for better circulation ??
I can then put draught stopper across the laundry n bathroom door to minimise outside cold air. This way the system would generally have already warmed up air to work with.
Thoughts???
Hi Ganesh,
Yes, you should first try opening the bedroom doors to provide a pathway for your return air. It might also be worth getting your ductwork checked for leaks if the problem persists.
-Trey
Hi Trey,
We had a Mitsubishi heat pump installed in May, and it’s doing fine. I noticed in the sheet metal return duct, in the basement, that a previous home owner had cut open a 8 x 8 square to allow more return flow. I resealed that, and removed the grill from the only return, in our top floor. It’s open now, (no pets!) and I’m going to put a more open screen on it, but I noticed that there seems to be air coming up from the duct work. Doesn’t seem right to me! What do you think?
Hi Trey,
Disregard my previous message.
I did the toilet paper test, and the airflow was sucking air down into the duct. Weird, because when I put my hand in the duct, I seemed to feel the opposite.
Thanks anyway.
Marc
Hi Marc,
Glad you got it sorted out! Yes, its pretty deceiving when you try to feel which way the air is flowing. The toilet paper test always works.
-Trey