The pre-filter catches cat fur before it reaches the HEPA. Every 2 to 4 weeks, unplug, vacuum the fur off and put it back. Allergy symptoms are a doctor call.
In this guide
Unplug it, vacuum the pre-filter, put it back
Open the back of your purifier and there it is: a gray fuzzy mat that used to be your cat. That's the pre-filter doing its job. Pull it out every 2 to 4 weeks, vacuum the fur off with a brush attachment, and slide it back in. Cat homes lean toward the short end of that range.
Where to put the purifier and which one to buy are in our air purifier guide. This is the upkeep that keeps it running.
Your purifier's manual or the maker's filter care page. Care steps vary by model.
Two minutes and a cat who's out of the room.
Step 1: Unplug it and open the filter
Power it off, unplug it and open the filter cover. Lift out the filter. Most pet purifiers stack a pre-filter, a HEPA layer and a carbon layer in one unit, so you're cleaning only the outer layer.
Step 2: Vacuum the fur off the pre-filter
Hold it over a trash can and shake loose fur off first.
Run the brush attachment over the surface in one direction.
Vacuum is the default. Wash only if your manual says the pre-filter is washable, and let it dry completely before it goes back.
Step 3: Put it back and keep it running
Reseat the filter, close the cover and plug it in. Run it all the time. A purifier only cleans the air while it's on.
Step 4: Swap the main filter on schedule
The pre-filter gets cleaned. The HEPA and carbon layers get replaced on the maker's schedule. Our pick, the LEVOIT Core 300-P Air Purifier for Pets, has a 3-stage filter: pre-filter, H13 HEPA and a pet filter with extra activated carbon for pet smell. Run it low and it's as quiet as 24 dB, so it can stay on all night. The catch: the pet filter is where the smell ends up, so swap it on schedule.
It's sized for rooms up to 222 sq ft, so bedrooms and the room your cat sleeps in are its best fit.
Already own the Core 300? The LEVOIT Core 300 Replacement Filter (Pet Allergy) is the swap.
Mistakes that clog it faster
Skip these
Wedging it in a corner. Leave space around the intake.
Never cleaning the pre-filter. Fur that gets past it ends up in the main filter.
Switching it off between cleanings. Run it all the time.
Forgetting the floor. A purifier handles the air, not the hair on the couch. Our cat hair removal tips cover the rest.
Allergies and your purifier
A clean pre-filter keeps the purifier working, and a purifier is one part of the picture. For real allergy symptoms, talk to your doctor.
FAQ
How often do I clean the pre-filter?
Every 2 to 4 weeks in a cat home, or whenever you see the fur building up.
Can I wash the pre-filter?
Check your model's manual. Some are washable and some are vacuum-only. A washed one has to be fully dry before it goes back.
