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Can You Have Too Much Return Air? (Quick Answers)

Return air plays a great role in providing you great comfort and you can furnish and decorate each space by placing return air. 

In fact, the placement of vents in your home can make a huge difference but you’ll need to make wise decisions on how many numbers of return air you need and where to place them in your house.

Can you have too much return air?

It’s not ideal to have too much return air as it won’t affect the amount of heat entering the room substantially where there’ll be too much of cold air. In fact, one return is enough for an average room size, but if the room is big enough, you can have two to three return air for better comfort.

Though it actually depends on the size of the room, having too much return air will not be ideal. Normally, it’s not possible to supply too much return air as it’ll be a matter of huge waste and cost. Moreover, it’ll not work as effectively as you are thinking. 

It actually won’t affect the amount of heat entering the room substantially and the amount of cold air in return will be too much. 

As the blower and ductwork will move only so much air and the total air movement will be cut in half and you’ll feel too much cold air than the warm air. Because it will enhance the rate of airflow by cooling the space by supplying and removing warm air. 

So, it’s wise to calculate the number of return air considering the size of the room. 

As like too much return air is not good for the HVAC system, only one return for your whole house is also not acceptable. Central return-air is not sufficient for the whole house as there will be a lack of new air to pull in or air returns. 

Having more than one return air installed at the busy places of the house is necessary. One return air for each room is also acceptable as it works pretty well but if you’ve large room, adding two to three returns will work more effectively. 

It’ll reduce unnecessary stress on the system by increasing the flow of air supply quickly.

Can you have too many return air vents?

The number of return air vents required to maintain constant air pressure actually varies by room size. You can have 2 to 3 return air vents in a large room. Many air vents will reduce the workload by minimizing the stress on the system. 

It would be a good approach to enhance the rate of airflow because air vents function to cool the space by supplying and removing air, so having many entry points would be beneficial. However, a small-sized room doesn’t require too many air return vents. 

How big does cold air return need to be?

To ensure the air conditioner operates efficiently, the cold air return size is normally determined by the furnace’s CFM output and square footage. It should typically be sixteen by twenty inches in size. 

This sixteen-by-twenty-inch cold air return can supply 1500 CFM of air and requires high pressure to force the air. But it’s wise to determine the size of the air conditioner first. If the duct is rectangular, multiply the size of the conditioner in tons by 144 square inches. 

The square root of the answer will determine the size of the air return.

How many return air vents do I need?

The size of the space and the system’s architecture are the most important factors in calculating the number of return vents needed. There should be one good-sized return vent in each room to exchange the airflow by creating air pressure. 

However, if the room is large enough, installing two or three vent returns will improve the airflow rate. If the room is smaller than 100 to 150 square feet, just one return vent is required. The criteria are actually dependent on air velocity and the size of the filter grill.

How do I know if I have enough return air?

To examine the return air if it is sufficient or not follow these techniques:

Place a tissue near the inlet grille opening: 

To begin, place a piece of tissue at the inlet’s entry point first to see if there is enough air flowing into the grille. If there is, the tissue will be pulled against the opening.

Check the supply vent inhaling rate: 

For conditioning, the supply vent intakes the same amount of air from the room as the return vent exhales. If the supply vent is functioning properly, it will indicate that the return vent has sufficient air.

Check the temperature fluctuation: 

if there isn’t enough return vent air, the air conditioner will blow hot air instead of cold air, and the furnace’s return vent will blow cold air instead of hot air. It will also have distinct changing temperatures in each room. 

If there is no such condition, it is apparent that the return air system is working well and that there is enough air for exhaling into the system.

Check the air pressure: 

There should be an equal amount of airflow in each corner of the room. If the area closest to the system gets colder quickly, but the distal corners have different temperatures, it will be obvious that the return vent isn’t getting enough air. 

If nothing else comes up, it’ll be a matter of having adequate return air.

Should there be a return vent in every room?

It’s actually necessary to have more than one of these return vents installed at strategic places in the house because it would be impossible for the central return-air grille to pull in air when rooms are closed. And for proper comfort it’s ideal to have a return vent in every room

If every room has return vents there will be no problem of inconsistent room temperatures and room-to-room pressure imbalance.

Where should air returns be located?

There’s actually no specific rules where to locate the air returns but here are the places you can locate air returns considering you requirements of cooling or heating: 

Floor or basement: 

Air returns located in the basements is one of the ideal locations as the heat will travel the shortest distance and will be circulated back properly. It actually works very well if it’s for heating as it can draw cool air from the floor.


For the cooling system return air, the best place for return air is near the ceiling because air would be able to circulate throughout the whole room more freely. Moreover, while using less energy in this process, they also won’t easily get clogged by dust and debris.

Opposite the supply vents: 

It’s a good technique to place the air returns  on the opposite side of the room where the supply vents are located. As a result, the system will allow proper airflow to rotate through the room timely.

Bedroom adjacent to living room: 

If bedrooms and living rooms lack air circulation, it’s required to locate air returns to bedrooms that connect the hallway adjacent. As a result, it’ll resolve the room-to-room air pressure imbalance and give you proper comfort.

What happens if return air is undersized?

The return grilles won’t be able to recirculate back enough air return if the return air is undersized. So the size and the number of vents should be calculated by an experienced contractor otherwise, it may:

Increase energy bill: 

To provide comfort and recirculate the air, the system has to run longer than normal. It’ll increase the heating load of the furnace and the system has to push the air more speedily than normal. As a result, it will increase the energy bill than normal.

Cause disturbing noise: 

Undersized return air will face troubles while pushing air and the system will forcefully push the air more faster. As a result, the air flow will be loud and it’ll create a disturbing noise. You’ll notice whistling or popping types of strange noise. 

Affect health: 

If the return air is undersized, it’ll cause poor airflow as it takes time strain and effort to get all the air out and you will experience it like if you are breathing in through a straw while jogging. 

You’d be hyperventilated as your body won’t get enough air to circulate back to your body.

Inconsistent room temperatures: 

The undersized air flow system will not work for your entire house properly and you’ll experience hot and cold spots for the inconsistent room temperature. It may hamper your comfort.

Final thoughts

Though air returns work very effectively to provide comfort, installing too many air returns won’t work as it cools the space by supplying and removing air and you’ll experience too much cold air. So, it’s wise to select the number considering room space and heating and cooling requirements.