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How often should you check the filter with pets?
Dogs and cats shed hair and dander, and the return grille pulls it straight into the filter. Tell us who lives with you and what filter you use for a sensible check interval.
Check your filter every
60 days or soChange it sooner if it looks grey or you can see hair on it — whichever comes first.
This is typical guidance, not a rule. Your filter's packaging and what you see on it matter more.
Pets and your system
Vacuum the returns
Hair collects on the return grille before it reaches the filter. A quick vacuum every week or two keeps air moving.
Keep dogs away from the outdoor unit
Dog urine corrodes the thin aluminium fins and the coil. A small fence or planter around the unit — with space for airflow — helps.
Watch for chewed wires
Thermostat wires, the outdoor unit's cable and the line-set insulation are tempting to chew. Covers and guards are cheap.
Don't block floor registers
Pet beds over a floor register block the air for the room. Move the bed a little to the side — the pet will still find the warm spot.
How the interval is worked out
We start from a typical interval for your filter — about 90 days for 1-inch, 120 for 2-inch and 180 for a 4–5 inch media cabinet — then shorten it: to about two-thirds for one pet, half for two, and 40% for three or more. A heavy shedder or someone sensitive to dander shortens it further. The result is rounded to five days, with a 20-day minimum.
