How to Find the Right HVAC Filter Size

How to Find the Right HVAC Filter Size

Your HVAC system is not a small investment. Fortunately, these systems typically last 15 or 20 years, and you can maximize their lifespan with regular maintenance from a qualified HVAC technician.

Changing the air filter is part of that. This component takes a lot of wear and tear when it filters out pollutants. When the air filter gets full, you can change it yourself, provided you know the right HVAC filter size and rating.

Why Does the Air Filter Size Matter?

The size of your air filter is imperative for getting an appropriate replacement. If you get a filter that’s too big, it won’t fit in the slot on your HVAC system. You can’t cut it down to size, as that will leave gaps that can allow environmental pollutants to get inside. It also affects your HVAC system’s function.

Likewise, you can’t use a filter that’s too small, even if it fits into the slot. This will also allow contaminants to come into your home. Always get the perfect size for your HVAC’s air filter slot.

Look at Your Existing Air Filter

The easiest way to determine your air filter’s size is using your current air filter. Typically, air filters have the size listed on the side in small print. This is usually the length, width, and depth in that order, measured in inches.

An example of a common air filter size is 20 x 20 x 1, measured in inches. This means the air filter is 20 inches long by 20 inches wide by one inch in depth. You should be able to find an air filter that’s 20 x 20 x 1 in a variety of options.

Measure It Yourself

If your filter doesn’t have a size listed on the edge, you can measure it yourself and do a little math to get the right filter size.

The dimensions will be a little smaller than the actual size of the filter you need. For example, a filter that’s 20 inches by 20 inches by one inch as a size may be 19.5 inches by 19.5 inches by .5 inches, which should be rounded up to the nearest inch to get the real size of the filter. It’s rare to find filters in odd sizes like these – they’re most always listed in full inches.

Measure Air Register or Air Filter Slot

If you no longer have an air filter, you can measure the air filter slot to determine its size. You may need to do some math to figure out the right size for the air filter, since the slot will have the measurements for the filter itself.

Just like measuring the actual filter, you will need to round up to the nearest inch again to get the appropriate air filter size. These sizes are generally standard and should be simple enough to find.

Where Is the Air Filter Located?

Most HVAC filters are located on the return air intake, near the return duct where the intake enters the HVAC system. There may be a plate that covers the slot to help you find it.

If the air filter is found on the air handling unit, you can find it near the return vent where it enters your home. As long as you can access this area safely and easily, you can change the air filter on your own without the need for professional HVAC technicians. If you’re not comfortable, feel free to bring in a pro.

Know Your Air Filter’s MERV Rating

After you determine the size of your air filter, half the work is done. The next step is determining the appropriate MERV rating for your home. This is a rating that measures how well the filter captures small particles in the air and how clean it keeps your air. The higher the MERV rating is, the better it is at filtering out contaminants.

It’s not a good idea to go with a higher MERV rating than you need. High MERV ratings will filter out contaminants better than lower ratings, but you won’t have the best efficiency. These filters are much thicker to filter effectively, which makes your HVAC unit work harder to circulate the air in your home and increases your energy bills.

A MERV rating of 5 to 8 is appropriate for most homes. You will capture pollen, dust, mold, and dander without a loss of efficiency.

If you have someone with respiratory conditions like asthma or allergies, then you may be better off with a MERV rating of 10 or 12 to get the appropriate air quality. These higher ratings can capture allergens down to one micron, but it comes with higher energy bills.

If you need HVAC maintenance or repairs, contact us at Proskill Services to schedule an appointment!

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