Air Vents: When It’s Okay to Block Them

Our short and simple answer? Never.

Here’s why.

Increased Pressure

Your heating and cooling equipment was set up for your home’s specific square footage. When you close air vents or block them with furniture, the same amount of air is being pushed through your ventilation system but with increased pressure because of limited opportunities for air flow.

Not only does it force your HVAC system to work harder—shortening its lifespan—but it also results in frozen air conditioning coils, overheated furnaces, cracked heat exchangers, and leaks in duct systems. Those issues come with both danger to your home AND big price tags for repairs.

Mold and Mildew

Because of humidity, moisture will collect behind the blocked vent, causing mold and mildew to not only fester, but to infect the air blowing through your entire house. This is a terrible scenario for any homeowner, but it can be especially dire for allergy and asthma sufferers.

If you’re blocking the vents with upholstered furniture—say, the wall vent is right in the middle of the only wall suitable for your couch—you’re setting your couch up to be a mold and mildew nest. This possibility is not only limited to soft, upholstered furniture. Rugs are also a prime breeding ground for mold and mildew, as is wood furniture.

Fire Hazard

Perhaps the most obvious (and most dangerous) result of a blocked vent is that it will cause a fire. How? 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.

Worried that you’ve been overworking your system?

Call your friends at BNG Heating & Cooling to schedule an inspection or maintenance checkup. We’ll be able to spot any signs of trouble before they become expensive mistakes