How to Close Your HVAC’s Fresh Air Intakes

An important part of your HVAC system, fresh air intakes help to increase performance, efficiency, and operating life. Using them properly can improve indoor air quality. They allow fresh air in from outside, which has many benefits. But there are many times when you might want to close air intakes, such as when air pollution is high or there is a wildfire advisory.

How Does a Fresh Air Intake Work?

How an air intake is operated depends on the type you have. It often takes the form of an open duct connected to an outside vent. An intake is a small, filtered vent that delivers air, instead of having the AC circulate air continuously through HVAC filters.

Your home may have multiple fresh air intakes to account for the latest building codes. This helps tighten the building envelope to prevent air loss and contamination from basements, crawl spaces, and attics. When properly installed, the intakes also block contaminants from unconditioned spaces from reaching the air in living areas.

Closing the Supply of Air from Outside

Typically, a fresh air intake is operated using a damper. First, locate the intake, which is usually placed in the attic, but it may also be ducted to the central air handler’s return side. Avoid covering an intake with a drape or curtain or stuffing it with insulation or rags. By blocking it, you could strain the system or, in the case of an intake serving a furnace, cause negative pressure that causes fumes and carbon monoxide to back up.

That being said, you can safely close an intake vent by sliding the dampers into the closed position. If the intake is operated with a fan, turn the fan off using the switch. The owner’s manual from the system manufacturer should tell you how the intake vents work. Follow the instructions on how to close the vents if necessary and otherwise operate and maintain them to maximize comfort and safety.

How to Find Your Intake Vents

Intake vents are often installed near furnaces and other gas appliances. They usually appear as grilled vents, but they’re not always out in the open. If you don’t immediately see it, the intake may be behind an appliance or a closed door or panel. You can also follow the air intake vent to its source, whether it’s the attic or a location on the exterior of your home.

Is Closing Fresh Air Intakes Enough?

During extreme conditions such as wildfires, closing air intakes is a wise idea. But the precautions don’t end there. You should also make sure to change HVAC air filters, as fine particles can find their way in, clog the filter, and get into the indoor air supply. Definitely close all windows and doors and turn off window units and bathroom fans. With these measures taken, it is safe to leave your air conditioning on. This is recommended as your AC will circulate fresh, filtered air and keep you protected indoors.

Contact Black Hills Inc. Home Services

A leading HVAC contractor in Olympia, WA, we can install, repair, or maintain your air conditioner, furnace, and other heating and cooling equipment. We also offer air quality services such as air duct cleaning and products such as micro air purifiers, UV purification systems, and ionizers. If you want to learn more about these, or have questions about how to use your fresh air intakes, you can reach us 24/7 by requesting service online or calling 888-538-5821. Our friendly, knowledgeable technicians will provide the assistance you need.