Can You Wash, Vacuum, Reuse or Recycle a Furnace Filter?

Most furnace filters are disposable and should be replaced, not washed or vacuumed. Only filters sold as washable or permanent are meant to be cleaned, and then only by following their maker's instructions. Washing or vacuuming a disposable pleated filter won't restore it, and a filter can look clean while it's already past its rated life. When it's time to throw one out, most used furnace filters go in the household trash unless your city or county program says otherwise. Here's what to do with each type of filter.

Can You Wash a Furnace Filter?

You can wash a furnace filter only if its maker sells it as washable or permanent; disposable pleated and fiberglass filters should be replaced instead. The label tells you which kind you have.

Disposable pleated and fiberglass filters

Disposable pleated and fiberglass furnace filters should be replaced on schedule, not washed. Filtrete states that even washable or reusable filters can't capture microparticles as well as its electrostatically charged filters. A replacement such as the Tier1 MERV 11 16x25x1 restores your filter's full performance. You'll find every size in our furnace filters range.

Washable (permanent) filters

Washable or permanent furnace filters are made to be cleaned and reused, following the filter maker's washing and drying instructions. ENERGY STAR advises checking the filter each month; if it's dirty, clean it if your system has a reusable filter, or change it if your system requires a replacement. Make sure a washable filter is fully dry before it goes back in, per its maker.

Electrostatic does not mean washable

An electrostatic filter is not automatically washable, because "electrostatic" describes charged filter media, not a reusable design. Tier1 pleated filters use electrostatically charged 100% synthetic media, and Filtrete's filters are electrostatically charged too. Both are disposable. Here's how to tell if your filter is washable:

• The frame or packaging says "washable" or "permanent."

• The frame is metal or plastic rather than cardboard.

• The maker gives cleaning instructions.

The table below shows what to do with each common filter type.

Table 1. What to Do With Each Filter Type

Can You Vacuum a Furnace Filter to Make It Last Longer?

Vacuuming a disposable furnace filter won't make it last longer, because filter life is about what the media has captured, not how it looks. Replace it on its rated schedule instead.

Why a clean-looking filter can still be spent

A clean-looking furnace filter can still be spent because, according to Filtrete, its filters capture microscopic particles that aren't visible. Filtrete does not recommend leaving a Smart filter installed past 0% life, regardless of how it looks. Using any filter longer than recommended may restrict airflow or cause the system to malfunction. For the full process, see how to change a furnace filter.

What vacuuming does to filter media

Air purifier maker Blueair advises that vacuuming or washing its filters could damage the filter media and decrease performance. That guidance is for Blueair's air purifier filters. For a furnace filter, follow its own maker's instructions, which for disposable filters means replacing them.

Reusable vs Disposable Furnace Filters

Reusable furnace filters save on replacements but need regular cleaning, while disposable filters are simply swapped on schedule. A refillable frame sits between the two.

How washable filters compare on capture

Washable furnace filters capture fewer microparticles than electrostatic disposable filters, according to Filtrete. Filtrete states that the difference is the electrostatic charge in its filter media. If capture is your priority, compare the MERV rating listed for any filter you're considering.

The upkeep each one needs

Disposable furnace filters need replacing on schedule, while washable filters need a monthly check plus cleaning and full drying. ENERGY STAR recommends checking any filter every month. With a washable filter, cleaning and drying follow its maker's instructions.

Refillable frames: a middle option

A refillable frame, such as Filtrete Refillable, lets you keep the frame and replace only the filter refill. Filtrete says the frame is reusable for the lifetime of the HVAC system, up to 20 years, while the refill isn't reusable and lasts up to 12 months. Frames come in nominal 16x25x4 and 20x25x4 sizes. Browse Filtrete air filters.

Here's how the options compare on what you keep and what you replace.

Table 2. Reusable vs Disposable vs Refillable

Can You Recycle Furnace Filters?

Most furnace filters can't go in curbside recycling, so a used filter usually goes in the household trash. Check your city or county rules, since programs differ.

Why most filters go in the trash

Most used furnace filters go in the trash because they're full of captured dust and debris, and most curbside programs don't list them. Filtrete directs its refill filters to regular landfill garbage. Your local rules have the final say, so check with your city or county.

How to throw out a used filter

To throw out a used furnace filter, remove it gently and bag it so the dust it holds stays contained.

1. Slide the old filter out slowly.

2. Put it straight into a trash bag and close the bag.

3. Take it directly to your outdoor bin.

For a Filtrete Smart filter, first remove the sensor with pliers while wearing cut-resistant gloves, because the wire is sharp. Dispose of the sensor under your local electronics guidelines, then throw out the filter right away.

This table shows where each item goes.

Table 3. Where a Used Filter Goes

How to Get the Most From a Disposable Filter

The best way to get the most from a disposable furnace filter is to check it monthly and replace it on its rated schedule. If you'd like fewer changes, a deeper filter may be an option.

Check monthly, replace on schedule

ENERGY STAR recommends checking your furnace filter every month and changing it if it's dirty, or at least every three months. Manufacturer intervals vary by depth, as the table below shows. Change sooner with pets, smokers, construction or a continuously running fan, per Filtrete.

Table 4. Manufacturer Replacement Intervals

Choose a depth that changes less often

A deeper media filter changes less often: Filtrete and AprilAire rate their 4-inch-and-deeper filters for 12 months. These need a slot or cabinet built for that depth; see filter depth: 1" vs 4" vs 5" and media air cleaner filters. Auto-Ship filter delivery sends replacements on your schedule.

Frequently Asked Questions

Can you wash a MERV 13 filter?

No, you shouldn't wash a MERV 13 filter unless its maker labels it washable. MERV 13 pleated filters sold at DFS, such as the Tier1 MERV 13 16x25x1, are disposable and should be replaced on schedule. Check the frame or packaging for "washable" if you're unsure.

Is an electrostatic air filter washable?

An electrostatic air filter is washable only if its maker says so. "Electrostatic" describes charged filter media, not a reusable design. Tier1 and Filtrete pleated filters both use electrostatically charged media and are disposable, so they should be replaced rather than washed.

How do I know if my furnace filter is reusable?

A reusable furnace filter is labeled "washable" or "permanent" and comes with cleaning instructions from its maker. Look on the frame and packaging. Cardboard-framed pleated filters are disposable. If you can't find any cleaning instructions, treat the filter as disposable and replace it.

Can I recycle the cardboard frame?

Whether you can recycle a filter's cardboard frame depends on your local recycling rules. Programs vary by city and county, so check with yours before separating the frame. When in doubt, bag the whole used filter and put it in the trash. Learn MERV ratings explained before buying a replacement.

How often should I check my furnace filter?

ENERGY STAR recommends checking your furnace filter every month, especially in winter and summer. Change it if it's dirty, or at least every three months. Deeper filters may last longer between changes, so also follow your filter maker's rated interval.

Sources

• Filtrete (3M) FAQ (washable comparison, appearance, intervals, Refillable, disposal, Smart filter sensor)

• ENERGY STAR Guide to Energy-Efficient Heating and Cooling; ENERGY STAR, Clean Heating and Cooling

• EPA Indoor airPLUS filtration bulletin (fiberglass MERV 1–4)

• AprilAire 210, 410 and 213 product pages

• Blueair support (vacuuming or washing filters)

• DFS product data (Tier1 media)