How Do I Find My HVAC Intake?

Your HVAC system contains numerous vents. The HVAC intake supplies fresh air to your furnace from outside your house. It delivers clean air and oxygen that enable the furnace to run efficiently and prevents the system from drawing air in from unconditioned areas, which can reduce air quality. You may wonder where your HVAC intake is so you can properly maintain it and make sure it’s unblocked.

Is It an Intake or an Exhaust?

You first need to know what you’re looking for. An exhaust vent has a flap. It serves a different purpose as this is where heat from kitchen range hoods, dryer vents, and bathroom fans escapes. A fresh air intake contains a screen where cool fresh air can enter. Once you find it, check for a feeling of suction when the furnace is on (feels like a breeze pulling into the vent). This means that it is drawing air into the system.

What About Cold Vents?

Don’t confuse an intake with a cold air vent. There may be up to 10 cold air vents in your house. Designed to draw cooler air back to the furnace, these are installed low on walls since cold air is denser and tends to sink. These vents are part of the return air supply.

What Does an HVAC Intake Look Like?

Oftentimes, the intake is on the side of the house. It can be in the form of a hood on an exterior wall. Look for a gray vent hood or a white or black plastic pipe. The fresh air intake leads to a duct that draws air into a vent near the furnace. It’s required in most parts of the home where a gas appliance is installed, except for the garage. Therefore, in most cases, you’ll need an intake for a gas heater, gas water heater, or gas dryer.

To find a fresh air intake, look for a grilled vent near a gas appliance. The vent may be out in the open. But it can also be installed behind the appliance or a door. If you can’t find it right away, look around and behind the furnace and check for an access panel. Both inside and outside, the vent should not be blocked. A screen on the outside prevents pests such as mice from entering and debris, snow, and ice from blocking the vent.

How to Maintain Your HVAC Intake Vents

It’s essential your intake vents are functioning. Otherwise, carbon dioxide and carbon monoxide (CO) can build up in your home. To avoid problems, follow these steps to care for these vents:

  • Check for signs of CO leaks, including a yellow/flickering flame, rust on the vent pipe, and moisture on windows or walls.
  • Clean the filters inside the fresh air intake.
  • Replace the AC/furnace filter at least every 30 days.
  • Make sure no materials or objects are covering the vent.


Also, be alert for signs of a backdraft. If moisture is condensing on windows, there’s rust on the grillwork in front of the furnace, or there’s hot air around the exhaust vent, a backdraft may be occurring. It’s a common sign of an unbalanced airflow. Ghosting, created by soot on walls, is another sign of a ventilation problem. Contact a professional when anything doesn’t seem right with your furnace.

Contact Black Hills Home Services

Whether you need help with an HVAC intake or suspect there’s a problem with your furnace, Black Hills is here to help. We restore the heat and maintain HVAC systems for homeowners throughout the Olympia area. To request heating maintenance or repair, schedule service online, fill out our appointment request form, or call 888-619-0086