Just because you cover the air vent, it doesn't indicate your HVAC system knows that. It will certainly continue to release air to those vents, and also if they're closed, you might cause a buildup of atmospheric pressure and not enough air movement which can damage your system.
Yes, all home vents should be free of obstructions. Blocking vent puts undue pressures on your blower motors air movement. There also could be a filter located behind this vent. Locating furniture in front of vents with filters only supports the idea that filters will not be changed out in a timely manner.
A build up of pressure can be caused by covered vents. This could lead to a cracked heat exchanger which in turn can lead to leaking carbon monoxide. Covering your vents can damage your HVAC system and cause cracks that could allow air to escape your ducts. This can lead to higher energy bills.
Dangers of Blocked Cold Air Registers
If your HVAC system is designed this way, blocking off a single return vent can wreak havoc on the system and lead to: Pressure imbalances that let allergens and pollutants get pulled into your air supply from unconditioned areas.
EXPERT RECOMMENDATION: If you want to try to balance the airflow throughout your home, you should not close vents completely; HOWEVER, you can close them slightly (not more than 75% closed) to help distribute air better to the areas that need it most.
The real concern is impeding the free flow of heated or cooled air. However, in a well-designed system, a vent's placement accounts for the likelihood of some obstruction. Yet, uniform airflow is essential for temperature consistency, which is why it's not a good practice to cover vents fully.
You want a good 10” between large, dense furniture for optimal airflow from a floor vent or any other vent. Covering a floor vent with furniture will simply diminish the efficiency of air flow and temperature control in the space.
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.
Air Quality Issues
Placing a bed over a floor vent can significantly impact the air quality in your bedroom. Here's how: Reduced Airflow: When you cover a vent, you're blocking the designed path for air circulation in your home. This can lead to stagnant air in your room, which may feel stuffy and uncomfortable.
Return vents are usually larger than supply vents and are in large rooms in the home. The return vents in your home help equalize the pressure that changes as your HVAC system heats or cools your home. These vents should never be fully closed because closing them off restricts airflow and strains the system.
While blocking air bricks may seem like a good way to keep the cold out, it can cause more harm than good. Covering these vital vents stops fresh air from flowing into your home. This lack of airflow leads to damp and moisture buildup. Damp conditions are perfect for wood rot and mould growth.
Vent covers: Each vent should have a properly fitted vent cover at the end. This not only prevents the vent from sucking in dust and other debris, it also helps blend vents into your decor and even creates optimized airflow in and out of the vent.
An air return on the floor collects much more dirt and debris such as hair and lint. For this reason wall air returns will require less frequent cleaning. Floor air returns must be clear of obstructions and heavy furniture. Transferring your air return to the wall will allow you to utilize your floor space more freely.
The engine's combustion relies heavily on air, which mixes with fuel to generate energy. In the absence of a sufficient quantity of oxygen, an engine will not be able to generate power, and it may not even start. Whenever the air filter in your car's engine becomes too clogged, it may start to misfire.
Fresh air intake vents are simply the way your home takes in fresh outside air, making sure the air inside your home isn't overtaken by contaminated or toxic air. It is an air duct that starts in the space where the furnace is located – usually the basement – that leads to an outside vent.
When vents are obstructed, heat can build up in the ductwork, increasing the risk of a fire. Additionally, if flammable materials are placed near blocked vents, the chances of a fire spreading rapidly are heightened. It is crucial to keep your vents clear of any obstructions to minimize the risk of fire accidents.
Trying to block or hide the air vents
Avoid blocking air vents with pillows, furniture, plants, or pictures. When the air vents are blocked it means that heated or cooled air needs to squeeze by what is blocking it to reach the rest of the room.
Make sure if you put a bed over a vent, it is at least 18 inches above the floor and has an open base. Air return vents are usually much larger than air supply vents and are often installed on the wall of the room instead of the floor. These vents should not be blocked or restricted in any way.
You most likely thought covering your air vents would certainly save you energy, but it does the opposite. Considering that this could damage your cooling and heating system, fractures and other damage could allow air to leave your air ducts and cost you much more in energy bills.
Blocking the return air supply to the air handler or blower compartment reduces the amount of air that flows easily into the system. The fan's speed won't slow any more when you close off the returns, and it creates positive air pressure.
In addition, there should be a sign indicating the presence of a fresh air intake. The space between the fresh intake and the exhaust is about 5 feet when it should be 15 – 30 feet.
You should never close your return vents on purpose, but it can happen accidentally. “It can happen from people not paying attention and throwing a rug over it or a couch that doesn't have feet, and they cover the return,” Smith says. Keep furniture at least 10 inches from return vents to allow proper airflow.
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.
Vent Clearance
All your air vents need at least six inches of clearance from all furniture, drapes or other household items to ensure proper system breathing.