Pet owners usually want a purifier for one of three things: allergies, hair, or smell. A purifier is good at the first, weak at the second, and only fair at the third. Knowing which problem you have saves money.
Allergies: where a purifier helps most
The proteins people react to come from a pet's skin flakes, saliva and urine, not the hair itself. Cat allergen in particular rides on tiny particles that stay in the air for a long time and stick to furniture and walls. A true HEPA filter captures those airborne particles well. That is why allergy groups commonly recommend a HEPA purifier in the bedroom, along with keeping the pet out of that room.
Hair: mostly a vacuum job
Pet hair is heavy and falls to the floor quickly. A purifier's pre-filter catches some loose fur near the unit, which is useful because it protects the main filter, but it will not keep floors and couches clear. A vacuum with a sealed HEPA filter, regular brushing (outside if possible) and washing pet bedding do more for hair.
Odor: needs carbon, and the litter box needs scooping
HEPA filters catch particles, not smells. Odors are gases, and only an activated carbon filter adsorbs them. Two things to know:
- Carbon amount matters. A thin carbon-dusted sheet fills up in weeks. A filter with loose granular carbon, measured in pounds, lasts far longer.
- Litter box ammonia is hard. Plain activated carbon holds ammonia poorly. Filters with treated carbon or zeolite do better, but daily scooping and a fully changed box do more than any filter.
Are "pet" models worth the extra cost?
Pet versions of popular purifiers often differ from the standard model mainly in the pre-filter or carbon layer. Compare the smoke CADR and the replacement filter price, not the label. If odor is your main problem, a heavier carbon filter is worth paying for. If allergies are, CADR is what counts.
Sizing for a pet household
Pets keep putting allergen back into the air, so buy above the usual rule of a smoke CADR equal to two thirds of the floor area. See how to size a purifier. Pre-filters clog fast with fur: vacuum or rinse them (if washable) every couple of weeks so airflow stays up.
Other things that help
- Keep pets off the bed and out of the bedroom if anyone is allergic.
- Use a MERV 11 to 13 filter in central air if your system can take it, and run the fan more often.
- Hard floors and washable covers hold less allergen than carpet and upholstery.