In the heating cycle, blocked cold air returns can cause the heat exchanger inside the blower compartment to store too much heat and eventually crack. If the cracks are too large, the furnace can emit carbon monoxide into your home’s air.

Is it OK to cover a cold air return?

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.

What happens if return vent is covered?

What Happens When A Return Vent Is Blocked? Very similar to blocking a heat register, blocking an air return vent restricts the air flow in your home. Blocking air return vents causes your system to work harder, as there is less air flow to move the air back to the furnace.

Can you put something over an air return?

Even with proper space, a big, flat piece of furniture can still restrict air flow enough to stop the flow of air back into your HVAC system. Open or backless shelving may be placed in front of an air return vent, but do not drape any fabric on the shelves as that can get pulled against the vent due to the flow of air.

What happens if return air blocked?

What Happens When Return Vents Are Blocked? The system will have to work harder to take in air, ultimately pulling it in through minute cracks in the home’s exterior. The HVAC system’s parts may wear out sooner than they should, and ultimately, malfunction and fail.

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.

Can covering a vent cause a fire?

Covering a vent can cause a fire. While rare, the heat can spark the heat exchanger connected to the vent. This leads to a fire breaking out and then spreading throughout the property. As mentioned, this is rare and it is not something you should expect to happen by covering the vent.

What is the purpose of return air vents?

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.

What is the purpose of cold air return vents?

The Purpose of Your Cold Air Returns



The return registers draw stale air into the ductwork, where it’s pulled through the filter to capture dust and debris and then delivered back to the HVAC equipment for reconditioning.

Why is cold air coming out of my return vent?

So why is cold air coming out of your vents? It is most likely a leaky duct system—but you should have your home’s heating efficiency checked out by an HVAC professional.

How do I know if my cold air return is blocked?

You can generally identify a blocked air duct by a distinct drop in heating and cooling efficiency, increased energy costs and occasionally a musty, dusty smell throughout the home. Blockage usually comes over time, by a buildup of dust and debris that just accumulates until it begins choking the system.

How do I know if my return vent 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.

How many cold air returns should a house have?

Your Home Might Not Have Enough Return 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.

Why do I have two air returns?

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.

Why does my return vent smell?

Unfortunately, mold or mildew growth from moisture in the air may be the root cause of the smell. As mold grows inside return air ducts, the air flowing through the ducts carries a musty odor to your rooms. These smells may cause headaches or aggravate health issues such as asthma or allergies.

Where is the best place to put a cold air return?

Place your cold air return vents on the inside walls of buildings at the lowest point. The return vent pulls cold air from the bottom of the room and returns it to the furnace to be reheated and returned as warm air. Unlike supply vents, return vents do not need to be cased in metal.

Does every room need a cold air return?

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.

Should cold air returns be high or low?

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.

How do you tie a cold air return?

When you're cutting through we're doing joint material with ducting or anything like that it's a good idea to use a tin foil tape foil tape seals all air gaps.

How do you cover a return air vent?

Much like the louvered doors, louvered shutters can be used to hide a return air vent without obstructing airflow. These can be hung over the return vent like a picture would be or secured to the wall with hinges allowing you to open and close the shutters when it’s time to replace your return vent filters.

Should my basement have a cold air return?

I recommend that all basements should have at least 2 supply registers and 1 return register in the basement/equipment area just to keep that area slightly warm or cool and the air fresh. If you are going to finish that area to be used as living space, then more supply and returns will be needed.