What is the purpose of a cold air return?
The importance of “cold air” returns. These are the vents that are usually on the wall and they do not have a control mechanism to open or shut their flow. Their purpose is to allow air to return to the furnace to be heated or cooled. It is an air inlet. If your home has returns in most rooms this is the best setup,...
Where is the cold air return in a house?
That means the space between two wall studs. If you have this type of air return system in your home then you can have a vent at the ceiling and at the floor. In the picture you can see the cold air return close to the ceiling.
Should you block cold air returns in the summer?
Block the upper vents (you don’t want to draw warmer air). Open the lower vents (you want to draw colder air). Block the lower vents (you don’t want to draw colder air). Open the upper vents (you don’t want to draw warmer air). It makes quite a lot of sense to block cold air returns in the summer.
Should there be two sets of cold air return registers?
But in the winter, would that not also return the hot air needed to heat the room. Should there be two sets, one for summer near the ceiling, and one in winter, near the floor to get rid of the cold air? Tim Schoell, Omaha, NE DEAR TIM: Ideally you want to have cold air return registers in every room.
Can you close off a cold air return?
Your return vents are usually larger than your supply vents. They don't have louvers like registers do, which means you can't open and close them.
Do you close cold air returns in the winter?
Adjust Return Registers for Winter It's important to remember that hot air rises and cold air falls. In the winter you want the cold air to be drawn through the return registers leaving the hot air behind. By opening the lower registers and closing the top ones you keep hot air in and draw the cold air out.
Should return air vents be closed?
Because hot air rises and cold air falls, you need to adjust your return vents with the seasons. In the summer, your lower vents should be closed and your upper vents should be open. In the winter, your upper vents should be closed and your lower vents should be open.
Should cold air returns be sealed?
Return systems should be “hard” ducted and sealed with mastic in order to be airtight. Building cavities should never be used as return ducts. Stud bays or cavities should not be used for returns.
Should you close vents in unused rooms in winter?
When vents are closed, that pressure builds up, potentially causing damage to the HVAC system. Increased air pressure can create cracks and holes in the ductwork. It can also cause your furnace's heat exchanger to crack. Leave all air vents open to prevent extensive damage to your home's heating system this winter.
Should I close off unused rooms in winter?
Many homeowners think it's a good idea to close air vents in unused or infrequently-used rooms during the winter months in order to save money on heating. Should you do the same? The short answer is no. As a matter of fact, doing this can lead to the need for a home furnace repair.
What happens when you cover a return vent?
Blocking air return vents causes your system to work harder, as there is less air flow to move the air back to the furnace. This continued strain on the HVAC system can lead to a decrease in performance and more HVAC repairs down the road.
What is the purpose of cold air return vents?
The Purpose of Your Cold Air Returns The return registers draw stale air into the ductwork, where it's pulled through the filter to capture dust and debris and then delivered back to the HVAC equipment for reconditioning.
Is it OK to cover a return air vent?
While you should have a filter on your air return vent to prevent too much dust or moisture from entering your air system and recirculating back to you, you should never actually cover a return air vent. Keep furniture and even curtains at least 10” away from the vent opening in order to allow for proper air flow.
How do you seal air return?
2:095:04How to Air Seal Return Air Duct - DIY Duct Sealing - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou could also do the same thing with caulk. But I just like spray foam better it tends to fill theMoreYou could also do the same thing with caulk. But I just like spray foam better it tends to fill the gaps a little better so now we're going to put the mastic. On.
How do I know if my cold air return is working?
Try this simple test when your HVAC system is running: get a piece of tissue paper and dangle it about six inches from one of the return vents. You should be able to see it being gently pulled towards the vent. Next, place it up against return vent and see if the air suction holds it in place.
Why is my return vent not pulling air?
If you feel no air is blowing from vents in your house, vent blockage is most likely to be the issue. You might be blocking your air vents unknowingly; a piece of furniture might be in front and blocking the airflow, or you might have closed some vents on a chilly day and forgotten to open them again.
Should dampers be open or closed in winter?
In most homes, dampers going to the upstairs are open in the summer and closed in the winter. By closing the dampers to the upstairs in the winter, it allows for the heat to rise naturally after first being introduced into the lower levels of the home.
Should you close upstairs vents in the winter?
If you have a top/bottom return vent setup, close the top vents in the winter months. Closing the top vents will make your system draw in air from the bottom vents that are at the low point in the room where cold air settles.
Should return vents be open or closed in summer?
Open High Returns in the Summer Therefore, opening the right return vents in the summer and winter significantly improves the distribution of air by your forced-air system. You'll also enjoy more even heating and cooling throughout your home. In the summer, open your high returns and close the low ones.
What happens when you cover a return vent?
Blocking air return vents causes your system to work harder, as there is less air flow to move the air back to the furnace. This continued strain on the HVAC system can lead to a decrease in performance and more HVAC repairs down the road.
How many cold air returns do I need?
Ideally you want a cold air return register in every major room in your home. This would not include bathrooms and closets, but bedrooms, living ro...
Where are cold air returns located?
Cold air returns are located on interior walls in a home, typically close to the floor or low on the wall. You want to make sure that cold air retu...
Where is the cold air returning to on a furnace?
The cold air from the returning vents is cycled back into the furnace where it is heated and cycled back into the house. Do you have questions abou...
How Many Cold Return Air Vents Do I Need?
A house may have anywhere from 1 to 10 cold air vents. Here are two ways how you can calculate how many return air vents you need:
Why do furnaces need cold air return vents?
That’s because we have to at least match the quantity of hot air furnace produces. To keep ‘breathing’, furnace cold air return vents have to supply enough air to the furnace. If we miscalculate how many return vents to install, the furnace will get insufficient airflow and it will start ‘suffocating’; operating at lower than 100% capacity.
How much pressure does a cold air return vent have?
Even floor cold return air vents (the place where pressure is the highest due to cold air going down), we don’t get that kind of pressure. At most, you will get anywhere from 10% to 30% of that; that’s 150 CFM to 450 CFM per standard vent. The assumed average is about 300 CFM. There is a large range of CFM’s a standard-sized cold air return can let through, however.
Why are furnace vents installed low on the wall?
Air return vents are necessary for the ‘inhale’ process. They are located on the walls or floors; they are installed low on the wall because cold air has a higher density and it accumulates near the floor.
Where is the coldest air in a house?
The basement is usually where the coldest air in our house is located. Basement air has two distinct features:
Should you adjust the return vents?
Some homeowners are already aware that you should adjust return vents with the season. The air return grille should adjust to different room temperatures.
Should you close cold air vents in the summer?
It makes quite a lot of sense to block cold air returns in the summer. If you use cold air vents only for the furnace (not for air conditioning), you should close all cold air vents. They serve no function in the summer.
How does cold air return work?
The function of the return side is fairly simple: cold, stale air is drawn into the ductwork through the return registers, it’s pulled through the air filter, then it’s delivered to the HVAC equipment where it’s reconditioned.
What is the effect of less conditioned air on the system?
Less conditioned air output, which creates temperature and humidity control problems and a decline in your comfort level.
How to ensure there is always enough airflow in HVAC?
You can help ensure that there’s always sufficient airflow through your HVAC system by keeping your cold air return registers unobstructed by household items like long drapes, area rugs, furniture and children’s toys. You can also: Vacuum or dust your supply and return registers frequently to keep them free of debris.
What are the two main sides of HVAC?
Your HVAC system’s air distribution network consists of two distinct sides: supply and return. Both sides must be fully functional for reliable HVAC performance, which makes it critical to keep your cold air returns unobstructed so air can flow unrestricted through the system.
Why do you vacuum your supply and return registers?
Vacuum or dust your supply and return registers frequently to keep them free of debris.
Can an HVAC system have multiple return registers?
If your HVAC system is new, your home may have several return registers . If your system is older, you probably have supply vents in every room but just one return register per floor. In this case, a single obstructed return grille can severely restrict airflow through the HVAC system and lead to serious issues like:
What is a return air grill?
These are the vents that are usually on the wall and they do not have a control mechanism to open or shut their flow. Their purpose is to allow air to return to the furnace to be heated or cooled. It is an air inlet.
Is a return grill an air inlet?
It is an air inlet. If your home has returns in most rooms this is the best setup, allowing for the best circulation and air flow. But sometimes we see that people cover/close them up because they don’t realize their importance. Some homes have one or two large return grills centrally located.
Where is the cold air return in a house?
In most homes the builders will use the wall cavity as a cold air return. That means the space between two wall studs. If you have this type of air return system in your home then you can have a vent at the ceiling and at the floor. In the picture you can see the cold air return close to the ceiling.
Where should I look for cold air returns?
The first place you should look is your heating and air conditioning. The area that I am going to talk about are the cold air returns. When you buy a home today or any home built with heating and air conditioning, the cold air returns are usually installed close to the ceiling. Normally just about every room will have them.
How does a fan keep the house cool?
When the air turns on the fan sucks air into the return air vent, thus pulling the warm air from the ceiling and cooling it down, which keeps the house cool. Now in the winter time this system is not very efficient. Remember the hot air rises and the cool air stays low.
What happens when the heat turns on?
Remember the hot air rises and the cool air stays low. When the heat turns on it is pulling the warm air from the ceiling, reheating air that is already warm. Ever notice in the winter if you sit on the floor maybe watching TV, its a little chilly close to the floor.
Can you see a bathroom ceiling fan in the winter?
You may not see them in a bathroom if it is small, however larger bathrooms may have them. Having them close to the ceiling is great for the summer time when you run your air conditioning, but not good in the winter when you have the heat on. Let me explain. Heat rises, and cold air stays close to the floor.
Where should the cold air return vents be located?
These should be located at the top of the wall on an interior wall. The supply registers should always be on an exterior wall preferably under a window or near a door. You don't need two sets of cold air return vents. The reason is simple. The supply vents should be in the floor and the cold air return grilles are high on wall.
Where to install cold air return register?
You can install a cold air return register above the door from each room that connects to the hallway. The air flows through these openings from each room. The air flows across the ceiling in the hallway towards a larger cold air return that does extend to the basement furnace.
What would happen if you could see air coming out of the floor registers?
If you could see the air come out of the floor registers, you'd see it be pulled across and up through the room. Because your body is in this path way, you get the benefit of either hot air or cold air being drawn across your skin providing you comfort.
Is the basement hot or cold?
In the winter the reverse is true. The basement is hot, main floor comfortable, and the upstairs is cold. Every supply vent is open on the upstairs, and closed in the basement.
Do high ceilings need air mixing?
That is the general rule... But air mixing may be needed, high ceilings could require both returns... A professional needs to evaluate what you have and examine how it can be modified.
Do vents stay open all the time?
Most systems are designed so ALL vents remain open all the time...
Where to put return air?
It's best to put them on an interior wall across the room from the supply duct. © 2018 Tim Carter
Where should HVAC return air ducts be?
"An HVAC return air duct should be in every room except a bathroom and kitchen. They should be on interior walls across the room from the supply ducts that should be washing exterior walls with conditioned air."
Why does my furnace need return air?
The reason for return air is simple. Your furnace is simply a recirculating pump. Instead of pumping water, it is pumping air. We need to get the air back to the pump. Furthermore, without a return air duct in each major room, the supply duct air has to "push" all of the air in the room out of the way as it makes its way towards you.
What is the air duct in your house?
The air ducts in your house should be designed exactly like the blood vessels in your body. Think about it. The veins and arteries supplying blood to the different parts of your body, even out to your fingers and toes, are the same size as the veins and arteries returning that blood back to your heart.
What happens if you live in a house that is too hot?
If you live in a home that has rooms that are either too hot in hot weather or are cold in cold weather you could have a return-air duct issue.
What is the purpose of a return air grill?
The intent is to wash the exterior walls with heated or cooled air. You are trying to combat the heat or cold at its source. The single giant return air grill in the floor balances the load at the furnace motor but does nothing to promote cross-ventilation in each room.
How to get the most bang for your return air buck?
If you want to really have a way to get the most bang for your return air buck, think of installing grill covers on the wall that have operating louvers. This will allow you to choke down rooms possibly on the first floor that are drawing too much air.
