How to Find the Perfect Air Filter Size

When it comes to air filters, size is essential. The wrong size can lead to air leaks, reducing filter efficiency and allowing contaminants to bypass the filter material. To make sure you get the right size, you need to measure the air intake and round up to the nearest whole number. Here's a look at how to find the ideal air filter size.

Using a measuring tape, measure the length, width, and depth of the inside of the air filter vent. Make sure to round up to the nearest whole number for the standard size. It is important to note that the actual size should be 0.25 inches to 0.5 inches smaller than the standard size. For example, a filter labeled 10 X 12 X 1 measures 10 inches long, 12 inches wide, and one inch thick. Incorrectly installed or improperly sized filter frames can cause air leaks, significantly reducing filter efficiency.

If an air filter is too small, air gaps will be created and contaminants will bypass the filter material. Most people won't find the size of air filter they need at the local home improvement store. If the filter fits properly, use the numbers on the sides to choose a replacement every 60 days, or as recommended by the manufacturer. When you buy air filters, you'll see the words “nominal size” and “actual size” together. Round up to the nearest inch to get the nominal filter size, which is the measurement you'll use when buying a filter.

Changing the HVAC filter is just part of the routine maintenance you must perform on your system. We recommend removing the existing filter and measuring it to confirm its actual dimensions. You can also choose not to use factory-installed filter grilles and have an HVAC professional install an external filter grille for a thicker filter. If you have a Trane Xb tue1c100a481ab, there's nothing inside that keeps the filter in place with a resolution of 20×24, but it's best to measure it yourself. To make sure your air filters are working properly and efficiently, it's important to get the right size. Measure your air intake and round up to get your standard size.

Then subtract 0.25 inches to 0.5 inches from that number for your actual size. This will help you get an air filter that fits properly and keeps your home safe from contaminants.

Catherine Plessner
Catherine Plessner

Devoted bacon trailblazer. Subtly charming burrito aficionado. Infuriatingly humble coffee advocate. Certified foodaholic. Incurable sushi guru. Award-winning travel lover.