Best Washable Furnace Filters for any Application

The best washable furnace filters will have a high MERV rating, comes in plenty of sizes, and is designed for excellent air filtration.

The best washable air filter I could find was the K&N 20x20x1 HVAC Furnace Air Filter. It has a MERV rating of 11, will trap fine particles, and comes in plenty of sizes.

If you have an uncommon-sized furnace, then you can purchase something like the FLANDERS SM100S Furnace Air Conditioner Filter and cut it down to the size you need.

Below you’ll find reviews for the best washable air filters and answers to some commonly asked questions.

Let’s get started.

Our Top Picks

K&N Furnace Washable Air Filter
K&N Furnace Washable Air Filter
  • Synthetic polymer
  • Stiff plastic frame
  • HVAC filter
Aluminum Electrostatic Air Filter
Aluminum Electrostatic Air Filter
  • MERV 8 Rating
  • Lasts forever
  • Easy to wash
Aqua-Flo Premium Washable Air Filter
Aqua-Flo Premium Washable Air Filter
  • MERV 6
  • Polyester
  • 84% arrestance efficiency

Best Washable Furnace Filter

K&N Furnace Washable Air Filter

Key Features:

  • Synthetic polymer
  • Stiff plastic frame
  • Merv 11

This furnace filter comes in four different sizes 20x20x1, 20x24x1, 20x25x1 and 20x30x1.

No matter what type of furnace shape you have, you should be able to find a washable air filter that fits.

It has a MERV rating of 11 which is high enough to capture dust, pollen, dust mites, mold, pet dander, and smoke.

When it’s ready to be cleaned, all you need to do is rinse it out with a low pressure hose and then let it dry. Once it’s dry, replace it in your filter register.

This washable air filter is made out of synthetic polymer.

You should be able to get 30 uses out of this filter, which should last you around 15 years with 2 washes per year.

When using this product, users mention that they were impressed with the high air flow this washable air filter allows.

You also get screws to screw down the furnace filter if you find that it rattles once you install it.

One downside is that you may need to purchase weatherstripping to get a good seal.

Another downside is that since the MERV rating is so high, you’ll need to wash the air filter often to remove all the debris that it catches.

Overall, you should be able to get many uses out of this washable air filter and save money for years to come.

  • Easy installation
  • Easy to clean
  • Durable frame
  • Can be noisy
  • Fitting require a couple of pieces of weatherstrip

Also Great Washable Furnace Filter

Vega Air Furnace Filter Washable

Key Features:

  • Can be cut to fit
  • Dense material
  • Lightweigh

Another option you should consider when looking for washable furnace filters are cut to fit options.

This way, if you have odd-sized furnace filters, you can simply cut them to the size that you need.

You can purchase sizes that come precut, but you can always cut it down to the air filter size you require.

While this is an economical option, you don’t have the same MERV rating that the option first came with.

This can be detrimental for anyone who suffers from allergies and requires higher filtration throughout the home.

If you have dogs or cats, then you may also have issues cleaning the hair out of this washable air filter.

When cutting down this air filter, some reviewers mention that some small pieces were left behind.

If you’re ok with cutting down your own filters and don’t own any cats or dogs, you should be able to get good use out of these washable furnace filters.

  • Easy to wash
  • Reduces electricity use
  • Removes harmful particles
  • Not rigid enough
  • Cuts leaves quite a few small pieces behind

Best Electrostatic Furnace Filter

Aluminum Electrostatic Air Filter

Key Features:

  • MERV 8 rating
  • Easy to wash
  • Lasts forever


Another option for washable air filters is electrostatic furnace air filters.

They’re made out of metal and can be washed relatively easily.

This air filter also has a MERV rating of 8, which is higher than most filter materials around a MERV rating of 4.

They use static electricity to help capture dust and fine particles.

Consider that the metal will be much easier to clean over time.

It’s recommended to clean this unit once every 1-3 months depending on how much you use your furnace.

This filter comes in an 18x20x1 size, so if you have a different sized furnace, then double-check before purchasing.

For anyone who doesn’t mind spending a bit more, maintenance will be much easier than any other air filter on this list.

  • Easy to clean
  • MERV 8 rating
  • Lasts forever 
  • Not able to be custom fit
  • Expensive compared to other options

Best Budget Washable Furnace Filters

Aqua-Flo Premium Washable Air Filter

Key Features:

  • MERV 6
  • Polyester
  • 84% arrestance efficiency


Furnace filters don’t have to break the bank. This washable air filter comes in a 10x10x1 size and has a 6 MERV rating.

If you require a larger size or want to buy in bulk, you can buy up to 10 feet and cut down the polyester material yourself.

You’ll be able to cut down the pads with a utility knife to fit any one-inch-sized air filter or AC unit.

What’s great about this style of filter is that the material on the inside is rigid and doesn’t require a frame for support.

You can reuse this material several times before having to replace it.

This material isn’t just for washable furnace filters, it’s also suitable as a filter for a freezer or even as a pump filter.

Compared to the option first, it does have significantly less MERV rating but is considerably less expensive.

It also doesn’t have a frame but the material should be able to stand on its own.

If you want to have customizability to cut down your own washable air filters and save on cash, this option is hard to be beat.

  • Needs no frame for support
  • Can be washed
  • Allows correct air flow
  • Only comes with a small piece for the price
  • Tad too thick

Also Great Budget Washable Air Filter

FLANDERS Furnace Air Conditioner Filter

Key Features:

  • ‎Synthetic
  • Reusable
  • Cut-to-fit

This 20x30x1 air filter can be cut down to size, washed, and reused without any issue.

You’ll be able to use it without purchasing an additional frame.

Cutting your own washable air filters may be preferable to buying pre-cut sizes if you have a non-standard-sized furnace.

You can get two to three filters out of this material and keep one ready to go if you decide your current one needs a wash.

It comes with a MERV rating of 4.

If you are in a home with dogs, cats, or people with allergies, you should opt to go with the K&N 20x20x1 HVAC Furnace Filter instead. The additional MERV rating will trap most particulates in the air.

While this furnace filter is great for anyone on a budget, the MERV rating is a bit lacking. You will however be able to get plenty of usage out of it regardless.

  • Better air flow
  • Needs no frame
  • Easy to cut
  • Slightly thin
  • Only comes in a non-standard size

Alternative Option

Aerostar Furnace Air Filter

Key Features:

  • ‎Pleated
  • MERV 8
  • Electrostatically charged synthetic material

While washable air filters are nice, you may not find the right size and not want to worry about cutting them down to size.

You can always opt to go with an affordable 6-pack that comes in a variety of different sizes for any sized furnace.

This furnace filter has a MERV rating of 8, which is small enough to filter particles like dust mites, spores, pollen and dust mites.

This electrostatic furnace air filter was made with high efficiency in mind and low air flow resistance.

It’s important that your filter doesn’t choke up your furnace, otherwise you may encounter issues down the line.

If you use your furnace a lot, then you’ll need to replace this every month during the winter.

As it comes in a 6 pack, you’ll only need to purchase a pack every 2 years.

Installation is super easy, just follow the arrows and install the arrows in the direction the air flow is going.

While the MERV rating is still lower than the washable filter in first, you won’t have to worry about washing these and can simply throw it away when you’re done.

Not everyone wants to cut down their air filter. You may also be in a scenario where you have a lot of pets and washing the air filter is a big hassle (or even impossible).

For anyone that wants a no-fuss solution, this disposable filter is what you’re after.

  • Simple to install 
  • Superior filtration efficiency
  • Reduce maintenance and utility costs
  • Can be noisy
  • Slightly thinner

Are Washable Furnace Filters Effective?

The downside of most washable furnace filters is that they have a poor MERV rating.

This means that they won’t do as well when catching particles that pass through the filter like dust mites, pollen and pet dander.

You can however spend a little bit extra and get washable air filters with a MERV rating of 11, which is even better than some disposable filters that you can purchase.

If you don’t have any issues with allergens and don’t have pets around, then you may be ok with a lower MERV rating.

Are Washable Furnace Filters Worth It?

Consider that you’ll need to change out your furnace filter once a month during the cold season (if you use your furnace often).

This can add up, and over time, it will cost a pretty penny.

You also will be to reduce unneeded waste that will end up in a landfill.

How Long Does a Washable Furnace Filter Last?

Washable furnace filters can last around 5 to 10 years if taken care of properly.

If you have many pets or particulates in the air (if a smoker lives in your house), your furnace filter may not last as long.

Can You Use a Furnace Filter in a Central AC System?

Furnace filters can be used interchangeably with a central AC system. You can use your reusable furnace filter instead of purchasing disposable filters for your AC system.

How to Clean a Washable Furnace Filter?

Step 1. To clean your reusable furnace filter, start by turning off your HVAC system.

You don’t want to run your HVAC system without a filter, so for the time being, let it stay off.

Step 2. Remove the filter (should be nearby the door at the bottom of your furnace or on the intake side of your HVAC system).

Step 3. Wash and rinse out your filter with a garden hose, soap, and warm water.

If you have stubborn residue on your filter, you may want to use dish soap that’s made to remove grease.

Step 4. Dry the filter.

Step 5. Replace the filter.

What to Look for in a Washable Furnace Filter?

Right Size

Finding the right-sized reusable air filter is important as you don’t want one that’s not big enough or have to force it into the furnace.

You can check what size furnace filter you need by looking at the filters you currently have.

If your furnace filter doesn’t have measurements on it, then you can either measure where the furnace filter should go or check your furnace’s manual. You can even call the manufacturer if you are still unsure.

MERV Rating

Furnace filters with a high MERV rating will do better at trapping finer particulates.

This is important if you have a smoker in the house or someone who has asthma or allergies.

Reusable filters can go up to as high as 11 MERV rating which is going to be high enough to help trap finer particles and keep your house clean.

The problem you may face is that higher MERV ratings will catch more debris, which leads to needing to be washed more often.


Not all washable filters come with framing. The reason for this is that the filter is made to be cut out and can stand on its own. You may however have better results with one that’s pre-framed and pre-cut to your exact specifications.

Final Thoughts

The best all-around washable air filter I could find was the K&N 20x20x1 HVAC Furnace Air Filter. It has a high MERV rating and is rated for 30 washes (which should be enough for 5-15 years depending on how much you use your furnace).

You can also opt to go with something like the FLANDERS SM100S Furnace Air Conditioner Filter. You’ll be able to cut it down to size, making it great for non-standard furnace sizes.

You can also use reusable air filters for your HVAC system, and not just your furnace.

About Roy Cohen

Roy Cohen has a burning passion for heating, cooling, and ventilation. He aims to help you save money on expensive repairs and bring you the best HVAC products. He has years of experience behind him in HVAC repair and garage maintenance.

You can find Roy at his LinkedIn or his email: [email protected]

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