Less reach: You may find that your cold or hot air from the air conditioner or furnace does not get as far as it should when your air vent is blocked. Your home's temperature may feel inconsistent, with hot or cold spots. Stagnating air: With reduced airflow, you will have stagnated air through the home.
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.
Signs of an air duct clog include: One room in your house is hotter than all the others. Dirty air coming from vents. Unusual spikes in electric bills.
You cannot block a return without risking damage to your furnace. They require a specific amount of inbound airflow. Putting a return in a bay window is a pretty dumb idea, though.
Insufficient return air can lead to higher energy bills. When your HVAC system doesn't receive enough return air, it must work harder to maintain the desired temperature, increasing energy consumption. Homeowners might notice a spike in utility costs without a corresponding increase in usage.
Reduced efficiency: Your HVAC system will work less efficiently if you block a return air vent. This will make the units use more energy and will raise your utility costs.
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.
You should never block your air return vents. Period. However, if you're looking to keep your home cooler in the summer, you can try closing lower supply vents and keeping upper ones open, allowing cooler air temperatures to come in from above and sink throughout your house.
Inconsistent air temperatures throughout your home could be a sign of not enough return air. You may also notice poor indoor air quality that feels stuffy. You also may notice an increase in your utility bill since your HVAC system might be working harder due to the lack of return air.
Blocked outside furnace vents could cause carbon monoxide to build up in your home, potentially resulting in carbon monoxide poisoning. A blocked vent also can affect the performance of your furnace, which may not run properly or not run at all when the intake or exhaust vent is blocked.
Limited Return Air
You will want to check and ensure that the return vents throughout your vent are not blocked. If these vents are blocked, it can lead to a lack of air being pulled back into your system.
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. This means the exterior cause of your vent's dirty situation may actually come from an interior problem.
Decreased Acceleration and Power
One of the first signs of a clogged intake air filter is a noticeable decrease in acceleration and power. If your car feels sluggish or struggles to pick up speed, it could be due to restricted airflow caused by a dirty filter.
Common Issues with Return Ducts: Clogs and Leaks
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.
By installing more return vents throughout your home, they can trap the air and remove it, improving air circulation. A drawback with this method is that your ductwork needs enough space to support additional vents. Smaller homes that can't add more vents need to pursue other options.
If there's not enough return air, your living room can be 10℉+ warmer or cooler than, for example, the bedrooms. Not enough return air in summer can cause rooms close to the central unit to be cooler and those farther from it to be warmer. In winter, rooms farther from the furnace can be too cool.
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.
Closing the vents doesn't do it any favors. In fact, instead of helping the air conditioner cool less, closed registers force the same amount of air through other ducts. This builds pressure in the system and makes your HVAC system work harder to distribute the air where you need it.
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.
Inadequate Insulation: Poor insulation in a specific room can result in heat loss, making it colder than the rest of the house. Check the insulation in the walls and ceiling of the affected room. Adding extra insulation or caulking gaps around windows and doors can help improve insulation.
Adding a return air vent will cost homeowners $350 per vent on average, depending on the vent size and duct material. A professional can assess the right duct material you need for your home and can give you an accurate estimate.
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.