Top rated by 7298 customers

Heat pump air filters

Buy replacement heat pump air filters made in the USA. Choose from 1000+ available sizes or order custom heat pump air filters with free shipping over $50.

Heat pump air filters

Filter size finder

Find the heat pump air filter you need by entering the width, length and depth or choose your size in the table below.

Filter Finder
Easy Installation

Easy Installation

Fits right into your system, no tools needed

Durable & long-lasting

Durable & long-lasting

Premium quality pleated filters in a rigid frame

All sizes available

All sizes available

Find your perfect fit with our complete size range

Guaranteed to fit

Guaranteed to fit

Compatible with all the major HVAC unit brands

Find your heat pump air filter size

10,000+ satisfied customers

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4.6 stars, 4478 reviews

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4.6 stars, 3597 reviews

When to replace your heat pump air filter?

For best indoor air quality, we recommend you change your filters regularly at different times depending on your situation.

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MERV rating comparison

 
Recommended for
Comparable ratings
Filtration efficiency
Dust mites
10+ microns
Pollen
10-100 microns
Pet dander
5-10 microns
Lint and fabric fibers
10+ microns
Mold spores
3-10 microns
Fine dust
1-3 microns
Smoke particles
0.3-1 micron
Smog and fine particles
0.1-1 micron
Bacteria
0.3-5 microns
Virus carriers
0.3-1 micron
Odors and gases
Molecular level
VOCs
Molecular level
Cooking odors
Molecular level
Learn more
MERV 8
Basic air quality,
standard homes
FPR 5,
MPR 600
90% of common particles
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
No
No
MERV 11
Better air quality, homes with allergies, pets
FPR 7,
MPR 1000-1200
95% of common particles
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
MERV 13
Superior air quality, health concerns, allergies
FPR 10,
MPR 1500-1900
98% of common particles
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
MERV 8 Carbon
Odor control, cooking smells, pet areas
FPR 5 + Carbon,
MPR 600 + Odor
90% of common particles
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
No
Yes
Yes
Yes

How to find your heat pump air filter size?

Check the label on your current filter or use a tape measure to determine the length, width, and thickness. Just make sure you know the difference between nominal and actual size.

nominal vs actual air filter size

Nominal Size Nominal size

Nominal size is what you normally see printed on the label. This is usually a rounded size which is often not the true size of your filter.

Actual Size Actual size

Actual size is the true size of the air filter, usually written in smaller font below the nominal size.

Measuring

Measure your current air filter or the length, width, and depth of the opening slot to get the actual size. Round it up to the nearest whole inch to get the nominal size.

Why Choose Furnace Filters

Why homeowners choose Filter King heat pump filters

Made in the USA

All our filters are made in the USA using quality materials — UL Classified and MERV rated to ASHRAE standards for reliable performance you can count on.

Easy to return/
exchange

Try it risk-free. Ordered the wrong size? Not what you expected? Send it back within 30 days for an exchange or a full refund. Simple as that.

Fast & free shipping

Free shipping on orders over $50, and most orders are processed within 24 hours. No waiting around — we get your filters out the door fast.

Frequently Asked Questions (FAQs)

Are heat pump filters different from regular air filters?

No. Heat pump systems use standard air filters — the same ones used in furnaces and HVAC systems. Just match the size and MERV rating your system requires. There's no need to buy a filter specifically labeled as heat pump filter.

How often should I change my heat pump filter?

It depends on the filter thickness. 1-inch filters should be replaced every 30 to 60 days. 2-inch filters can last 60 to 90 days. 4-inch and 5-inch filters can go 6 to 12 months between changes.

Replace your filter more often if you have pets, allergies, or live in a dusty area. A good rule: check it monthly and replace it when it looks gray or clogged.

Which way does the arrow go on a heat pump filter?

The arrow points toward the heat pump, in the direction of airflow. Air flows from your home into the return duct, through the filter, and into the heat pump — so the arrow should face the heat pump or blower motor.

Look for the arrow printed on the filter frame. If you install it backwards, the filter won't work properly and can restrict airflow.

What does a dirty heat pump filter look like?

A clean filter is white or off-white and you can see light through it. A dirty filter looks gray or brown, and the surface will be visibly clogged with dust, lint, and debris.

If you're not sure, hold it up to a light. If little or no light passes through, it's time to replace it.

Where is the heat pump filter located?

Most heat pump filters are located in one of three places: inside the blower compartment of the heat pump, in a slot between the return duct and the heat pump, or behind a return air vent on a wall or ceiling.

Check near your heat pump first — look for a removable cover or a slot where the filter slides in. If you have a return vent with a large grille, the filter may be inside there instead.

What size heat pump filter do I need?

Check your current filter — the size is printed on the frame. You'll see three numbers: length, width, and depth (for example, 16x25x1).

If there's no label, measure the filter yourself. Measure length and width first, then depth (thickness). Round to the nearest inch. If your size is unusual, you may need a custom-sized filter.

Can heat pump filters be recycled?

Most disposable heat pump filters cannot be recycled through regular curbside programs. They contain a mix of cardboard, fiberglass or synthetic fibers, and trapped dust and debris, which makes them difficult to process.

Check with your local waste facility for specific guidelines. Some areas accept them as bulky waste. The cardboard frame can sometimes be separated and recycled on its own if it's not contaminated.