What Are The Most Common Sizes Of Air Filters?

Filters provide numerous benefits for your system, house, and health. You must replace them frequently. Understanding the size of the filter you want is also essential. AC Repair in Apple Valley, CA, can assist in finding the correct size of the air filter.

Sizes of the Most Common Air Filters

Regarding furnace filters and air conditioners in Apple Valley, it’s essential to know what size you require. Three distinct dimensions are assigned to air filters. The first number refers to the product’s length, the second number indicates its breadth, and the third to its thickness or depth.

The following are some of the most popular furnace and air conditioner filter sizes:

  • 10 x 20 x 1
  • 14 x 20 x 1
  • 16 x 24 x 1
  • 18 x 30 x 1 
  • 20 x 20 x 1
  • 20 x 30 x 1
  • 12 x 12 x 1 
  • 14 × 14 x 1

These are the sizes you’d find in a home improvement store. These figures refer to the regular dimensions of your home’s return air vents, which manage airflow to and from your HVAC unit.

The Filter is of Incorrect Size

Many individuals install an incorrectly sized filter, which might cause issues. For one thing, this can significantly impact the number of air pollutants that are filtered out, resulting in poor indoor air quality. Second, this problem might force your HVAC system to work more than it should, potentially causing issues with your unit.

How to Determine the Filter Size

Not sure what size filter you need for your home? While determining the size may appear simple, it might be more complicated than you believe. Furthermore, if you purchase the incorrect size, there may be catastrophic consequences. You may notice increased energy expenditures, a malfunctioning system, and even health issues.

It is important to note that an airtight seal between the frame and the air filter is not required. It should, however, fit rather snugly with a tiny bit of room around the borders. You probably need a different size if you shove the filter into position. The idea is for the filter to slide into the frame easily.

Finding the Right Fit

Manufacturers estimate the sizes of air conditioners and furnace filters. It is known as the nominal size. The nominal size of the filter will remain the same regardless of brand. Nonetheless, it is critical to understand how this nominal size corresponds to the actual size.

DIY Dimensions

Not sure what size your filter should be? If not, the most obvious place to look is your existing filter, but only if it fits properly. Turn down your system, remove the filter from the compartment, and measure the measurements. If your filter fits perfectly, then this is the size you require.


Knowing more about furnace filters and air conditioning repairs in Apple Valley might help you pick the right one for your house. You may have cleaner indoor air and fewer system problems by utilizing a correctly sized filter and changing it regularly. Our professional specialists Masco & Sons, are here to assist you.