Blueair
Blueair Blue Pure 311i Max replacement filter
F3MAX · SKU 110037 · UPC 689122023298
"Depending on usage, your filter will last up to 9 months." That is not a calendar figure.
Find your unit below: air purifier filters and humidifier wicks. Each guide gives the exact part numbers, the models it fits, the near-identical models it does not fit, and how often the manufacturer says to change it — with the usage assumption behind that interval, which is the part most listings leave out.
Blueair
F3MAX · SKU 110037 · UPC 689122023298
"Depending on usage, your filter will last up to 9 months." That is not a calendar figure.
Blueair
⚠️ BLUEAIR DOES NOT STATE AN INTERVAL ON THIS FILTER'S PRODUCT PAGE.
Blueair
"6 months of operation", signalled by a red filter replacement indicator on the unit.
Blueair
110009
Approximately 6 months of operation — but Blueair is unusually specific about why that is an approximation, and it is worth reading.
Blueair
113807
Every 6 months, based on about 10 hours of use a day, per its Amazon listing and the FAQ on its store page.
Coway
3104756 · AP-2015-FP
"Filter Life Expectancy is 12 Months", per Coway's product page for the set.
Coway
3118096 · 3116999 · 3117063 · 3117062 · 3105422 · 3107167
Coway's manual gives a per-filter table rather than a single number.
Dyson
⚠️ NOT PUBLISHED IN THE DOCUMENT WE COULD READ.
GermGuardian
FLT4825 · FLT4825SM · FLT4825VO · FLT4850PT · FLT22CB4 · LB4000
⚠️ GERMGUARDIAN DOES NOT STATE AN INTERVAL FOR FILTER B ON THE PRODUCT PAGE ITSELF.
Honeywell
HRF-R3 · HRF-R2 · HRF-R1 · HRF-A300 · HRF-AP1 · HRF-APP1
Two different clocks, and they are not the same one.
Levoit
Core 200S-RF
"It is recommended to replace filters for every 6-8 months", per Levoit's product page for this filter.
Levoit
Core 300-P-RF · Core 300-RF · Core 300-RF-PA · Core 300-RF-TX · Core 300-RF-SR
Levoit states 6-8 months.
Levoit
Core 400S-RF · LRF-C401S-WUS
Levoit does NOT state an interval on the filter's own product page.
Levoit
LRF-C161-WUS · UPC 810043375559.
⚠️ LEVOIT DOES NOT STATE AN INTERVAL on this filter's product page.
Levoit
LRW-S602S-AUS · LRW-S601S-BUS
Every 3–6 months, depending on weather conditions and water quality, per its Superior 6000S manual.
Levoit
Vital 100S-RF · LRF-V102-YUS
"Designed to last 6–12 months", per Levoit's product page for this filter.
Levoit
Vital 200S-RF
"Designed to last 6–12 months", per Levoit's page for this filter.
Medify Air
⚠️ NOT STATED ON THIS PAGE.
Medify Air
"MA-40 Filter"
3,000 hours of use, per Medify's own FAQ.
Winix
116130 · Filter H
12 months for both layers.
Winix
1712-0089-01 · 1712-0089-03
Twelve months for both stages together.
Winix
1712-0121-00
Twelve months.
Prices are not published here: they move, and quoting one would go stale the same week. The amber button opens the current Amazon listing, which is the only place the figure is ever right. It is an affiliate link — what that means is set out in our disclosure.
Read it off the filter you are replacing, or off the rating plate on the unit — usually underneath or behind the back panel. Match that code, not the marketing name: brands reuse model names across revisions that take different filters. Each guide here lists the OEM codes, the units the filter fits, and the near-identical models it does not.
They exist and they are cheaper. What we can tell you is what the manufacturer documents about them, including anything they say about the warranty, and we print that per model rather than generalising. What we cannot tell you is how a given third-party filter performs, because nobody publishes comparable measurements for them — no AHAM entry, no independent test. That absence is itself the answer to the question.
Almost never, and doing it is how people quietly ruin a filter. The dense particle-capturing stage is generally not washable; what often IS washable is the pre-filter in front of it, and some units have a permanent one. The two get confused constantly. Each guide states which stage is which for that specific unit, using the manufacturer’s own instructions rather than a general rule.
That indicator is almost always a timer, not a sensor: it counts hours and has no idea a new filter went in, so it has to be reset by hand. The sequence differs per model and it is usually a button held for a number of seconds. We publish the documented reset sequence on each filter guide, taken from the manual for that unit.
You mostly do not, and that is the honest answer. A stated interval assumes a certain number of hours a day at a certain speed, in air of a certain cleanliness. Run the unit harder, or in a dustier home, and the real interval is shorter. Treat the number as the manufacturer’s planning assumption rather than a measurement of your home, and look at the filter: visible loading is better evidence than the calendar.