The Homeowner's Guide to AC Filter Sizes, Types, and Ratings Skip to main content

Whether you’re a first-time homeowner, or you’ve been changing AC filters for years, the air filter section of a home improvement store can feel a little confusing. Between the different AC filter sizes, types of filters, and brand names, how do you choose the right one?

Don’t let the air filter aisle intimidate you!

In today’s post, we will unravel the mystery behind buying the right AC filter. Take a minute and learn more about sizes, types, and ratings.

Narrowing Down AC Filter Sizes

Selecting the correct AC filter isn’t as much about the right brand as it is about the right size. AC filters come in the following sizes:

  • 16″ x 20″
  • 16″ x 25
  • 20″ x 25″

Selecting the right size is as easy as reading your owner’s manual. Manufacturers make it even easier for people who can’t locate the manual. You’ll find the size printed on the filter.

Tip: AC filter changes are an important part of routine AC maintenance.

Who Is MERV?

If you’ve never heard of it, you need to get to know MERV!

MERV stands for Minimum Efficiency Reporting Value. MERV is a numbering system designed to rate how effectively an AC filter removes dust and other particles from the air inside your home.

The American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) developed the system, and they assign a value between 1-16 to every AC filter on the market today.

Filters assigned a high MERV rating work better to filter harmful particles. People who deal with allergies, asthma, or other respiratory conditions should pay special attention to MERV ratings when they buy replacement filters.

Most AC filters have the MERV rating prominently displayed on the packaging.

So Many Types of Filters

Once you determine the size filter you need, you’ll need to choose which type filter works best for your AC needs. Filters come in several types including:

  • Disposable
  • Reusable
  • Pleated
  • Electrostatic
  • HEPA

If you’re on a strict budget and don’t have pets, smokers living in your home, or allergies, a disposable filter will suffice. They’re inexpensive and have a MERV rating between 1-4.

Reusable filters also have a MERV rating of 1-4. The name says it all, and even though you’re not getting better filtration, you will save money on replacements.

Manufacturers design pleated filters to filter more contaminants. With a MERV rating of 5-13, pleated filters can filter roughly 45% of airborne particles. You can buy a high-efficiency version with a MERV rating up to 16, which can filter out up to 85% of the contaminants.

Pleated filters are reasonably affordable, work in many (but not all) AC systems, and offer a significant improvement in air quality over disposable or reusable filters.

Electrostatic and HEPA filters have much higher MERV ratings, but unless you have a system designed to work with one of them, it’s not advisable to install one of these filter types.

Need to Schedule AC Service?

Now that you know more about AC filter sizes and buying replacement air filters, you’re ready to face the Texas summer, right?

Cooling season is also the time when AC systems often need extra TLC.

Whether you have a current service issue, or you’d like to schedule routine maintenance, we’re here for you! Contact us today to schedule an AC service appointment.

(936) 703-2130