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.
You could mess with the air flow. Just because you cover the vent, it doesn’t mean your HVAC system knows that. It will keep pushing air to those vents , and if they’re closed, you could cause a buildup of air pressure and insufficient airflow which could damage your system.
Fire Hazard. Perhaps the most obvious (and most dangerous) result of a blocked vent is that it will cause a fire. When you’re forcing your system to overwork, as mentioned in our first point, you put your furnace at high risk of setting on fire.
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.
It’s important to remember that hot air rises and cold air falls. In the winter you want the cold air to be drawn through the return registers leaving the hot air behind. By opening the lower registers and closing the top ones you keep hot air in and draw the cold air out.
Most people would tell you, no, you cannot put furniture in front of an air return vent . The bottom line is as long as the furniture piece is open on all sides and the bottom allowing the return air vent to draw in air to the heating and cooling system unobstructed, it should be fine .
Due to safety issues, heating concerns and air conditioning needs, you should never carpet over floor vents . As a general rule, ceiling mounted vents offer better cooling potential, while floor vents offer superior heat delivery.
It isn’t possible to have too many returns .. However, the blower will move only so much air . 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.
As long as there is space under the bed it should not be a problem. Heat rises and it will come from under the bed . Just make sure the vent isn’t totally blocked.
The biggest drawback of vent filters is restricted airflow . Filters slow the passage of air . As particles build up on them, the amount of obstruction increases. This can cause your system to work harder, using up more power and potentially overheating components.
Check for Simple Problems. If one room in your house is colder than the rest , the first things to inspect are the heating vents, ductwork and thermostat readings. Inspections of this sort should be performed at least once yearly.
When vents or ducts are clogged with dust and debris, the result is reduced airflow which can cause annoying noises. Another sign of poor ductwork, and a culprit of noise coming from your air return vents , is unlined return ducts.
If there is not enough return air available, your HVAC system will not heat or cool properly. If not enough air is brought back, your HVAC system will not be able to keep up with temperature demands. In some cases, two returns may be necessary to provide enough return air .
The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room. If the supply ducts are in the floor, then the return air should be located up high. This pulls the air across your body.