Is cold air return in basement needed?
If your basement is unfinished, there is really no need to be concerned about a cold air return vent. There is usually enough leakage that some air is still drawn from the basement into the system and replaced by heated air from a hot air duct. In fact, many people prefer this approach.
Can I put a filter on my cold air return?
to many filters on a system is not a good thing. The system is designed too run with the filter on the return or inlet side of the air handler or furnace. If you add filters on the return air grilles also, that will restrict the airflow even more which could cause problems with the unit freezing up etc.
Can you block a cold air return?
You should not block the cold air return even if you have more than one cold air return because you will cause inadequite airflow and uneven heating/cooling particularly in the room that the cold air return is being blocked. If you block enough of the airflow, you can damage your furnace and the air conditioner.
Should cold air return vents be closed in winter?
Since that warmer air is at the top of your room, you will want to make sure the highest air return is open and the lowest is closed. Conversely, in the Winter heating season, you will want to pull the coldest air back to the furnace to be warmed and create circulation. In these months, you’ll want the lower air return open and the upper air return closed. Properly Regulating Your Cold Air Return Vents
Is a cold air return necessary?
Cold air return vents aren't the most elegant feature in your home, but they exist for reason. These vents, commonly found in hallways or on ceilings, are absolutely essential to an air conditioner's well-being. Cold air returns take in warm air from your home's indoor spaces for use in your air conditioning system.
What happens if there is no cold air return?
If there is not enough air coming from the return vents (problems with exhaling), you will have problems with the air supply as well (problems with inhaling). You will practically see this insufficient 'breathing' as: Air conditioner blowing warm air (in the summer). Furnace blowing cool air (in the winter).
Is it OK to block a cold air return?
Long story short: It's never a good idea to cover up cold air returns. Don't succumb to the temptation, and always check that air is circulating freely when you move furniture. If your HVAC system isn't performing the way you would like, it might have other efficiency issues.
Does every room need a cold air return?
While it is a myth that air return grilles are required in each and every room in the house, it is definitely necessary to have more than one of these grilles installed at strategic places in the house. The most important place to have these would be the bedroom.
Should you cover cold air returns in winter?
In the same way that hot air rises, cold air stays lower. So when you're trying to heat your home, your lower return vents should be open to collect the cold air and your upper return vents should be closed to keep the heat from escaping.
How many cold air returns should a house have?
Ideally, every room except the kitchen and bath should have its own return air grille. At the very least, each level of the house should have one. Even so, many homes were built with just one or even no return ducts in an attempt to cut costs.
Why do houses have cold air returns?
For your furnace to run efficiently and your home to heat evenly, this airflow must be in balance. In other words, the amount of air that your furnace “breathes in” must equal the amount of air it “breathes out.” Cold air returns are what allow your furnace to “inhale” your home's air.
Where should the cold air return be 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 return vents are not blocked or covered by furniture so that your home can get proper air circulation.
Can you put a couch in front of a cold air return?
Home Inspection Insider explains that an air return vent needs 6-12 inches of space in front of it, and recommends that you do not put large, bulky furniture like couches and bookshelves in front of an air return vent.
Can a house have too many return air vents?
Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.
Will a cold air return make a room warmer?
When warm air is delivered to a room, the existing cold air in that room is pushed into the cold air returns. Once inside your cold air returns, that air travels through your ductwork back to your furnace where it is filtered, heated and sent back to warm your home.
Does a high efficiency furnace need a cold air return?
Since high efficiency furnaces draw air directly from outside, the furnace itself does not require a fresh air intake in order to replace inside air that otherwise would have been drawn from the room the furnace is located in.
What happens if you block your return air 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.
Does a high efficiency furnace need a cold air return?
Since high efficiency furnaces draw air directly from outside, the furnace itself does not require a fresh air intake in order to replace inside air that otherwise would have been drawn from the room the furnace is located in.
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.
Should you have a cold air return in basement?
Every house should have proper air return throughout the house including the basement. Believe it or not, every room, including the basement should be the same temperature. Ensuring good placement of cold air returns is critical to ensure proper distribution of air flow.
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...
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 return vents are not blocked or covered by furniture so that your home can get proper air circulation.
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 rooms, etc. Older homes might only have just one or two on each floor.
Why block air return vents?
Be sure to keep the area around your cold air return vents clear and clean so that air can recirculate properly. Blocking these vents can hinder your furnace or air conditioner from properly heating or cooling your home resulting in an air conditioner repair being needed. If some of your rooms feel “stuffy” you may need to add another return air ...
Where does cold air go in 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.
What are the returns at the top of a room?
The returns at the top of your rooms are hot air returns , since warm air rises. Amazing stuff, I know.
Do ductless furnaces return cold air?
Well, they do pretty much exactly what they say; they return cold air back to your furnace to be heated and then distributed throughout your home.
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 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:
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.
How much airflow can a 16x20 vent provide?
A typical air return vent size (16×20) can provide airflow with a maximum of up to 1,500 CFM. To achieve that 1,500 CFM, we need a big pressure pushing air through the ducts and through the cold air return grille.
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.
What is the Best Way to Maximize the Performance of Cold Air Returns?
When it comes to the cold air returns, you want them to work optimally so that your home’s airflow is balanced. So, it only makes sense that you would do whatever necessary to ensure that the cold air returns are doing their job.
How Do You Adjust Returns for Summer?
Similarly, you want the hot air to get drawn out in the summer while the cold air remains. Since cold air is heavier and drops to the floor, it only makes sense to close the registers that are closer to the floor.
Why are older homes not cold?
You may notice some rooms are stuffier, there is uneven heating, unbalanced pressure, and even higher energy bills .
Can cold air return be blocked?
This might seem a bit obvious, but cold air returns can get blocked in a number of ways. For proper airflow around your house, make sure that there is nothing blocking or obstructing your cold air returns.
Does Every Room Need a Cold Air Return?
Remember, there can be a problem with airflow throughout the home if there are not enough cold air returns. Unless you are paying attention to the airflow in your home, it can be difficult to know if there are enough cold air registers.
Why is it important to have return air in every room?
Therefore, having a return air in every room is very important to keep the air pressure balanced. One in, one out. Equal pressure means you can stay comfortably in your room.
What is the Purpose of Air Conditioner Return Air?
Return air is a must to draw the air in a room back to the air conditioner so that the air conditioner knows what is the current room temperature and adjust its supply air temperature accordingly . At the same time, maintaining balanced air pressure in the room.
Why do air conditioners have return vents?
It turns out that every room should have a return vent so that the air conditioner is able to sense the mixed return air temperature and adjust the supply air temperature accordingly to prevent overcooling or undercooling at certain rooms.
How does an air conditioner adjust temperature?
Since air conditioners adjust supply air temperature based on the return air temperature, each room contributed their room temperature via the return air. Then, the mixed return air temperature tells the air conditioner what is the average room temperature now. Hence, the air conditioner is able to adjust a more suitable supply air temperature for all rooms.
How much CFM per return air grille?
Say if we distribute the return air to each room, we are looking at an airflow of about 400-500 CFM per grille. Referring back to the noise data from the grille supplier, I’m looking at a noise criterion of <NC15. At below NC15, it is almost inaudible from a distance, assuming your return air grille is installed in the ceiling which most people do.
What temperature should a first floor air conditioner be?
Let’s look at one example, again, the first-floor air conditioner (indicated as D in diagram 1) is set at 25°C. If the living room temperature is currently at 27°C, the kitchen is at 25°C and bedroom 4 is at 24°C, the mixed return air temperature can be somewhere around 25°C. Although the air conditioner will still provide cooling, this time it is at a percentage of its full capacity. Thus, bedroom 4 will still feel slightly colder but it is much better than the previous example.
How long has Yu been in the air conditioning industry?
Yu was working in the air conditioning industry for the past 7 years, covering from design to installation and maintenance. Yu wish to share all the things he learned with the people around the world.
Why is air returning important?
First, they keep us comfortable. The air falls or is pulled back into the system to be recycled. In an optimum situation, it is then blown into a room at one area , circulating through the room, going back again at roughly the same rate to be reprocessed. This action helps maintain a constant temperature.
Where are air returns located?
In most homes, air returns are located on or near the floor. Depending on the type in your particular home, you may not be able to tell an air return from a heat or cooling vent. That’s fine as long as they aren’t blocked and you’re having no problems.
How does a fan circulate air?
The first is a gravity system where cooler air near the floor falls into the air return and ducting. The second is a forced-air type. A system fan creates a suction that helps pull air into the returns.
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.
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
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.
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."
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.
