Air Filters | All Sizes of HVAC, Furnace and AC Filters

how to measure your filter size

When it comes to air filters, you'll encounter two terms for size: nominal and actual.

Here's the breakdown to help you choose the perfect fit:

Nominal Size:

Think of it as the "advertised" size. It's a rounded-up, simplified number that manufacturers use for labeling and categorization.

It's typically displayed in larger font on the air filter frame.
For example, a filter labeled as a "20x25x1" nominal size might not be exactly 20 inches long and 25 inches wide.

Actual Size:

This is the exact, precise measurement of the air filter. It considers the true length, width, and depth of the filter, often including fractions of inches.

It is usually printed on the filter frame in smaller font or alongside the nominal size.

Why the Difference?

Nominal size simplifies labeling and makes it easier for consumers to browse and compare filters.
Manufacturers can have slight variations, so the actual size might differ slightly from the nominal size.
However, the nominal size provides a good starting point for finding a compatible filter.

Remember: A proper fit is essential. An air filter that's too small allows unfiltered air to bypass, reducing efficiency. One that's too large might not fit or could restrict airflow. By understanding the difference between nominal and actual sizes, you can ensure your HVAC system has the perfect filter for optimal performance and clean air.

CHOOSING THE RIGHT MERV RATING.

When it comes to choosing a residential furnace filter, it's best to factor in your household's health needs, the environment (including pets and other potential indoor pollutants), and your budget.

	MERV 8	MERV 11	MERV 13	Odor Eliminator
Best for	Standard Residential/Commercial Healthy Families	Superior Residential/Commercial Allergy Sufferers	Optimal Residential/Commercial Hospital Grade	ODOR ELIMINATOR Residential/Commercial Household Odors
Comparible ratings	MPR 600 & FPR 5	MPR 1000-1200 & FPR 7	MPR 1500 - 1900 & FPR 10	MPR 600 & FPR 5
Filtration	Captures 90% of Airborne Particles	Captures 95% of Airborne Particles	Captures 98% of Airborne Particles	Captures 90% of Airborne Particles
Dust, lint & debris
Mold, pollen
Dander, dust mites
Smoke & smog
Bacteria
Odor, vocs

I ordered the wrong air filter, now what?

At Filterbuy, we want you to breathe easy with the perfect air filter. That's why we offer a hassle-free exchange and return policy:

Ordered the Wrong Size or MERV Rating?

We'll gladly help you find the right fit. Simply contact us for a free exchange. Our friendly team will guide you to the perfect air filter for your needs. If you decide that you’d prefer a refund, you’ll be responsible for the cost of return shipping.

Change Your Mind Within 90 Days?

We understand. You can return your unopened and unused air filter for a full refund. However, you'll be responsible for the return shipping cost.

Prefer an Exchange? We Recommend It!

Exchanges are free and often much faster than returns. Plus, you'll get the perfect air filter for your needs right away.

What if I ordered my filter from Amazon?

If you purchased your air filter through Amazon, please refer to their return policy for instructions.

Other reasons for returns or exchanges

While we've covered common reasons for exchanges and returns, we know situations can vary. If you encounter an issue with your order or need to return or exchange your air filter for another reason, don't hesitate to contact us! Our friendly customer service team is here to help you find a solution promptly.

Shop with Confidence.

We're committed to your satisfaction. If you have any questions about our return or exchange policy, feel free to contact us. We’re always happy to help (:.