Where is the air filter in my home?

Short Answer:

If you have central air, your air filter is most commonly found in

A) a wall OR ceiling behind a large grate/vent or
B) next to your furnace or air handler, which is usually found in a basement, attic, or utility closet

Occasionally, you may also find your filter in a vent in your floor.

Air filters are most commonly found in one of two locations:

1) In a wall OR ceiling behind a large grate/vent

This is called the "return vent," which is usually much bigger than other vents in your home, and is where air is sucked in, as opposed to the other vents where air is pushed out
The vent is usually opened/closed with latches or flathead screws.

Wall Install

Ceiling Install

2) Next to your furnace or air handler (i.e. the HVAC motor)

Your air handler is normally found in a basement, attic, or utility closet
Your filter usually goes in a slot (between the duct and HVAC motor) or in a compartment covered by a metal door that, when opened, exposes the HVAC motor and wires

Furnace Install

Here are a couple of tips if you're having trouble finding your air filter:

It may also be on the floor. Just check if you have any vents on your floor.
If your filter is in the wall or ceiling vent, we recommend turning on your air, grabbing a tissue (preferably clean 😄), and holding it up to your vents. The correct return vent will suck up the bag (but of course be blocked by the grate) and that is where your filter might go. All other vents are pushing air out towards you.
If your filter is located in your air handler, it is found in what is called an "intake rack." This slot might be topped by a metal door or cover (that's usually pulled or latched open), which provides access to the intake rack. Depending on your specific furnace, the slot can be below, above, or to the side of your furnace.
- Pro tip: check to see where the tall, tower-like duct meets the motor, that's usually where the filter is.