Are All Air Conditioner Filters the Same Size?

When it comes to air conditioner filters, standard sizes may vary slightly. In fact, if you have to force an air filter in or out, it's the wrong size, so standard sizes are usually half an inch smaller than advertised. The filters are labeled with three-part dimensions. The first number is its length, the second is its width, and the third is its depth or thickness.

To understand the differences in the available filters, there are a couple of things you should know. The easiest way to identify the size of the AC filter is to remove the existing filter from its slot and examine the filter frame. Then use a measuring tape or other measuring device to measure the length, width, and depth of the inner edge of the groove or frame of the air cleaner. Step 1: Measure the length and width (L x W).

If the filter is not square, the smallest measurement goes first). No, HVAC air filters differ in quality and dimensions, and some have features that others don't. In most cases, we recommend using the filter that your HVAC manufacturer recommends matching with your system. Filters should be changed every 30 to 90 days, depending on the type and efficiency of the filter.

Filters don't need to fit a “tight seal”, but you should be able to easily install and uninstall the filter effortlessly. Improperly sized, or installed governable filter frames can cause air leaks, which significantly decreases filter effectiveness. It's best to have a little wiggle room in the slot of the HVAC unit, so you can easily slide the filter in and out without it bending or breaking. For common brands of HVAC systems such as Goodman, Lennox, Trane, Rheem York, Coleman and Carrier, most standard air filter sizes will work. Regularly replacing your air filter is the best thing you can do to keep your HVAC system running.

If you really want to clean the air as it flows through your HVAC system, you should consider installing a whole-house air purifier or ultraviolet light that goes inside your HVAC unit.