However, most HVAC contractors use a rule of thumb to determine the number of air vents needed. For example, for a standard residential HVAC unit, you'll generally need one supply vent and one return vent for every 100 to 150 square feet of living space.
One per room is ideal, but placing two or three in central locations can provide enough air circulation to maximize the energy efficiency of your HVAC and optimize indoor air quality, so your family stays healthy. If your home has multiple stories, you should have at least one return air vent per floor.
A general guideline is homeowners need one square foot of roof vent for every 300 square feet of ceiling space, if your home has a roof with a vapor barrier, or 1:300. If not, you should have one square foot of roof vent for every 150 square feet, or 1:150.
Cold air return vents should typically be placed lower on the walls or the floor since cold air naturally sinks. This placement helps capture the cooler air faster and more efficiently, allowing it to be recirculated through the HVAC system for heating or cooling.
Can You Have Too Much Return Air? Too much return air coming through your system isn't much of an issue because the fans and ductwork working to get that air back into the system only pull with so much force to make the HVAC system work correctly.
Symptoms include weak airflow and uneven cooling or heating throughout your home, with some rooms feeling much cooler or warmer than others. Homeowners should regularly check vents for consistent airflow. If you notice a significant drop in air pressure or uneven temperatures, it could indicate return air issues.
Instead, there should be at least one return vent in every room, with two or three being ideal. If your house has only one return vent, this is not a problem — make sure to keep the doors open in every room so the air can circulate properly. Make sure there are no furniture, draperies, rugs, etc. blocking return vents.
Up High: having an air return higher up on a wall will be better at sucking in hot air that rises. Making it more efficient at transferring this hot air back into your system to repeat the cooling cycle. Down Low: if you have your air return lower on your wall it will function better as a cold air return.
Hot air rises and cool air sinks. 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.
1. Openings shall not be located less than 10 feet (3048 mm) measured in any direction from an open combustion chamber or draft hood of another appliance located in the same room or space. 2. Return air shall not be taken from a hazardous or insanitary location or a refrigeration room as defined in this code.
The short answer is no, you can't install too many soffit vents. The air is cleaner and there is a nice breeze when the house is properly ventilated. This same practice applies to soffit vents, and it's much better to overventilate than to have air sit in the attic without movement.
Generally, the square footage of each room will determine the number of vents you need per room, because the influence of one vent will be altered when the room is larger than a certain square footage. That magic number is 100 square feet.
You can usually spot return vents on your walls, ceiling, or floors. Look for a white grille without shutters to spot an air return vent. These vents will typically integrate seamlessly into your home.
Having a number of return vents (preferably one in every room, but also 2 or three is far better than just one) creates regular air pressure.
It doesn't matter how few or how many vents your home has: if the AC can't do its job properly, your house won't be as cool, your electricity bill might be higher, and your AC unit will not be efficient. Keep rooms open to allow air to flow freely.
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.
If there's not enough return air, your living room can be 10℉+ warmer or cooler than, for example, the bedrooms. Not enough return air in summer can cause rooms close to the central unit to be cooler and those farther from it to be warmer. In winter, rooms farther from the furnace can be too cool.
Return registers can be large and centrally located in your home, or they can be in every room. HVAC professionals recommend that each room have a cold air return vent to help with flow and temperature control. These vents are typically found on an interior wall.
For example, for a standard residential HVAC unit, you'll generally need one supply vent and one return vent for every 100 to 150 square feet of living space.
If you prioritize heating, put the HVAC and vents in (or below) the floor. This principle works for return heating vents as well. Place returns for cooling in the ceiling where the warm air congregates and heating returns in or near the floor where the cold air congregates.
Turning your air vents so that the grate faces upward certainly won't hurt, but it likely won't be a magical cooling solution. From an aesthetic standpoint, facing the grates upward will make the fixture appear sleek and clean (since you won't be able to see into the wall).
Shutting the heating vents in your basement or another room you don't use very often is a great way to reduce energy expenses during the summer months. That being said, it isn't something you should do for more than two or three days at a time.
Closing the vents doesn't do it any favors. In fact, instead of helping the air conditioner cool less, closed registers force the same amount of air through other ducts. This builds pressure in the system and makes your HVAC system work harder to distribute the air where you need it.
In fact, when installing return ducts it is always advisable to avoid putting them in bathrooms or kitchens. This would just simply cause the heating and air system to circulate cooking odors and moisture throughout the system.
By installing more return vents throughout your home, they can trap the air and remove it, improving air circulation. A drawback with this method is that your ductwork needs enough space to support additional vents. Smaller homes that can't add more vents need to pursue other options.