3 Things to Know About Your Return Vents (2023)

FAQs

What do return air vents do? ›

Return vents: What is a return vent? These vents suck the air from each room and send it back to the air conditioning or heating system. Return vents tend to be bigger than supply vents, and you won't feel any air coming from them. When an HVAC system delivers air to a room, it increases that room's air pressure.

Make sure that you can feel the warm or cool air coming through the system by placing your hand in front of the vents in each room. Most return vents have a small lever that allows you to adjust whether they are open or closed. If you cannot feel any air coming through the vent, it means your vent is closed.

To identify a return vent, take a piece of paper and hold it up to the vent. If the paper is drawn towards the vent, then it's a return vent. Return vents are usually larger than supply vents, and they usually don't have adjustable slats to direct airflow since the air is going into the ducts instead of out.

The best location of the return vents depends on whether the system is heating or cooling the air. If it's cooling, the return vents should be near the ceiling, where the warm air collects, but if it's heating, the return vents should draw cool air from the floors.

Once again, NEVER close a return air vent. If you have operable cold air SUPPLY vents in your home, you can close upper supply air vents and keep lower return air vents open in the winter to keep your home cozy while allowing your heating system to work efficiently.

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.

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.

If you can hear air moving at your return, chances are you have an undersized return duct. This leads to high bills, annoying noise and pre-mature blower motor burnout- meaning decreased system durability.

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.

Usually, your air filter will sit in your return vent so that your HVAC system is handling clean air, free of particles and debris that can affect sensitive parts like evaporator coils in an air conditioning unit.

Which return vents should be open in summer? ›

Close top return vents.

(Hint: In the summer months, open the top vents and close the bottom ones to draw out air from a higher point in the room where it's hotter).

For optimal efficiency, it's ideal to have return registers installed. To ensure efficiency during the cooling season, your home should have high registers. High return registers draw hot air that rises to the ceiling back into the system to repeat the cooling cycle.

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.

Return registers also perform best on an interior wall—not one adjacent to the outdoors. Instead, that's where your supply registers should be, ideally under a window. Lastly, make sure the return registers aren't too close to the supply registers.

The short answer is no; you should not close air vents in your house. Closing vents can actually waste more energy than operating your system normally. How does closing air vents waste energy? Because when you close vents in unused rooms, your central air system will push the excess air to other places in your home.

Having two air return vents allows you to seasonally control which air is returning to the HVAC system. In older homes, this may not be an option. The theory is that in the Summer cooling season, you want to be circulating warmer air back through the HVAC system to be cooled.

While some dust and debris will enter your home, the rest may remain stuck on the vents' surfaces. Along with the air your HVAC system pushes through the ducts and vents, the air inside your home can lead to a dusty buildup — especially if your air conditioner recirculates dirt, pet fur, or other debris.

Ideally, you should have one in every room. The more the better! The presence of air returns will allow your air pressure to be consistent. If you only have one return vent in your home, your air pressure won't be optimal.

Keep couches, chairs and other large pieces of furniture at least 10 inches away from your cold air return vents. Avoid covering your cold air return vents with curtains, drapes or rugs. Always check your air filters and replace them when needed. Clogged air filters can also cause cold air return blockages.

Does the length of return duct matter? ›

Excessive Length

Longer ducts can increase the size of the air handler needed to supply the same cubic feet per minute (cfm), or the HVAC system may not be able to supply the designed cfm to all locations.

Since the air return sucks air, they are prone to getting clogged, especially if your home is particularly dusty. When vents or ducts are clogged with dust and debris, the result is reduced airflow which can cause annoying noises.

The Size Of Your Return Ducts

In most cases, if you are installing ducts in each room where there is a supply, you will want to go with the same size as your supply vents. If you are installing just one or two return vents, you will want to go with a 12-inch return for 2-ton units and lower. 14- inches for 3 and up.

The AC return vent is really a very simple part of the system, but it plays an important role in keeping your home cool. The air conditioner return vent works by drawing air from inside the room and pushing it back into the blower compartment to be cooled again before being sent 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.

Maintaining Air Pressure

As conditioned air is pushed in, the air already in the home needs a place to escape. Return air vents serve this purpose by helping to pull in the air and putting it back into the system. This is what maintains proper air pressure in a home.

EPA does not recommend that the air ducts be cleaned routinely, but only as needed. EPA does, however, recommend that if you have a fuel burning furnace, stove or fireplace, they be inspected for proper functioning and serviced before each heating season to protect against carbon monoxide poisoning.

Please note that you should not use Lysol to sanitize your HVAC system's return vents. Lysol has a high ethanol alcohol concentration, which means it is highly flammable.

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.

2 Other Supply and Return Ducts. All other supply and return air ducts and plenums shall be insulated with a minimum of R-6 insulation where located in unconditioned spaces, and where located outside the building with a minimum of R-8 insulation in Climate Zone 4 and R-12 insulation in Climate Zone 5.

Can you close off a cold air return? ›

While it can be tempting to block the cold air returns for rooms you're not using to save energy or place furniture against them to arrange a room, blocking these registers is one of the most common ways to undermine your cooling and heating system.

The temperature your AC puts out is relative to the temperature you set on your thermostat. So even though there's no single ideal temperature, you do want a 16°–22° F difference from the supply air and return air. Professionals call this temperature difference the evaporator Delta T.

Experts advise having your air ducts cleaned every 2 to 3 years to prevent many maintenance and health problems before they start. However, homes with pets or children with allergies should have their air ducts professionally cleaned more frequently than the recommended average.

Dust comes from many sources, including pet dander, dust mites, tracked-in dirt, and blown-in pollen. While it's true that the ductwork in your home may contain dust, the particulates often adhere to the inside of the ducts and are not dislodged when the furnace or air conditioner is running.

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.

M1602.

Return air openings for heating, ventilation and air-conditioning systems shall comply with all of the following: 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.

This balances the airflow through the system and ensures that there is plenty of air coming back to be reconditioned, filtered, and sent back out again through the supply ducts. If there is not enough return air available, your HVAC system will not heat or cool properly.

The consequences of inadequate return air pathways

Some of that air will find its way under the door and through interior leaks back to the central return vent. The rest of it, though, will push through openings and leak to the outdoors and into interstitial spaces. It leaks out.

The first thing most homeowners notice in the case of not enough return air are the hot and cold spots. Having some rooms that are hot and others that are cold is a tell-tale sign of not enough return air. Example: Let's say you have HVAC ductwork across your entire house.

Should cold air returns be closed in summer? ›

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.

The ductwork in your residential forced-air HVAC system is the network of pipes through which heated or cooled air travels. In addition to the supply ducts that provide the conditioned air, there is also a system of return air ducts that bring expended air back to your HVAC system.