In most cases, they are positioned away from windows and exterior doors to avoid drawing in outdoor air directly. In multi-story homes, you'll find cold air returns both upstairs and downstairs to maintain balanced air pressure and efficient circulation throughout the house.
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.
Ceiling vents do a better job cooling and floor vents do a better job heating. If your priority is cooling, put your HVAC in the attic and ducting and heating vents in the ceiling. If you prioritize heating, put the HVAC and vents in (or below) the floor. This principle works for return heating vents as well.
Down Low: if you have your air return lower on your wall it will function better as a cold air return. This will allow your air return to draw in cold air as it sinks to the bottom of the room. Making it more efficient at recirculating this cold air through your furnace to repeat the heating cycle.
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.
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.
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.
A lack of return air can cause your HVAC system to overheat, leading to frequent shutdowns or overheating warnings. This overworking can also result in the air conditioner blowing warm air, especially in high temperatures.
In winter, enable the bottom cold air to return and in the summer, enable the upper return. It's that simple.
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.
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.
Cons Of Ceiling Vents
Remember, heat rises, so if it starts at the ceiling, it has nowhere to go but up. Exposes HVAC system to unconditioned spaces – Attics tend to be dusty and prone to extreme temperatures, adding wear and tear to the equipment and increasing heat transfer loss.
A second return duct can lower static pressure if the airflow bottleneck is on the return side. If the static is on the supply side, adding a second return will do nothing. So it's usually a good idea.
In an air conditioning climate the return duct goes near the ceiling to draw off the hot air and cool it down. In a heating climate, the return duct goes near the floor to draw off the cold air and heat it up.
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.
So how much space does an air return vent need to work properly? 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.
In most cases, they are positioned away from windows and exterior doors to avoid drawing in outdoor air directly. In multi-story homes, you'll find cold air returns both upstairs and downstairs to maintain balanced air pressure and efficient circulation throughout the house.
Does Every Room Need Air Return Grilles? 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.
The warm, less dense air rises while the cooler, more dense air sinks down. At home you may ask, “Does cold air rise or sink?”. The answer is cold air sinks.
Because heated air rises, return registers should be installed high on the wall. In the summertime, the return registers will be well-positioned to pull the hottest air out of a room.
When it comes to cooling your home, return vents are best installed near the ceiling so they can draw in any hot air that has risen. Supply vents should also be placed high on the wall for better distribution of cold air throughout the room.
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.
You want to pull in the colder air so vents should face the floor! What if they are closer to the ground? Either way is fine, but aiming upwards looks better because you see less contrast between wall and grille.
While return vents don't always require filters, adding them provides additional filtration, improving indoor air quality and keeping dirt and debris out of your system.
Return air ducts must be sealed and unobstructed — Sealing return air ducts is just as important as sealing supply ducts. Sealing all duct section connections with mastic, a specialized rubbery sealant, or with metal tape prevents air leaks.