Short answer
Buy by part number, change the filter on the maker’s schedule rather than by how it looks, and reset the filter light afterwards. Makers’ intervals for the 26 purifiers we track run from about three months to about five years, most of them six to 12 months. Makers that address it all recommend their own filters.
The filter does the cleaning, and it’s the part you keep buying. This guide is built from the makers’ manuals, filter pages and spec sheets for every model in our comparisons of air purifiers, purifier fans and heaters and purifier dehumidifiers and humidifiers. To look up one model with a link to each source, use our air purifier filter finder.
Which filter fits your purifier
Match on the part number, not the family name. The number is in the manual’s filter section and usually on the old filter: IQAir prints it on each filter’s label, and Blueair puts the model name on a label inside the purifier.
| Model | Main filter | What it combines | Maker’s interval | Other versions and parts |
|---|---|---|---|---|
| Philips AC0650 | FY0611/30 | HEPA NanoProtect with a built-in pre-filter; no carbon | About a year | Also fits the AC0651 |
| Philips AC2220 | FY2200/30 | Pre-filter, HEPA NanoProtect, carbon | About 3 years (an average) | Also fits the AC2210 and AC2221 |
| Philips AC3220 | FY3200/30, a pack of two | Each: pre-filter, HEPA NanoProtect, carbon | Up to a year | Both are fitted at once, so replace both |
| Philips AC3420 | FY3400/30 | Pre-filter, HEPA NanoProtect, carbon | Up to a year | FY3401/00 humidifier wick, about every 6 months |
| Philips AMF870 | FYM860/30 | Pre-filter, HEPA NanoProtect, carbon | About 12 months | Also fits the AMF765 and AMF865 |
| Blueair Blue Max 3250i | 110410 | Particle and carbon layers (electrostatic charge, then a mechanical filter) | 6 months (spec table) to 9 (filter page) | Washable fabric pre-filters: 110434, 110443, 110446 |
| Blueair Blue Max 3450i | 110412 | Particle and carbon layers | Up to 9 months | Fabric pre-filters: 110433, 110445, 110448 |
| Levoit Core 300 and Core 300S | Core 300-RF | Pre-filter, main filter, carbon | 6 to 8 months | Pet Allergy (-PA) and Toxin Absorber (-TX); Mould and Bacteria (-MB) is in the manual but wasn’t on Levoit’s UK store |
| Levoit Core 600S | Core 600S-RF | Pre-filter, main filter, carbon | 6 to 12 months | Standard version only in the UK |
| Winix T500 WiFi | Filter O, 1712-0110-04 | Pre-filter, carbon, HEPA | About 12 months | Also fits the Zero Compact, A330 and A332 |
| Winix T800 WiFi | Filter GR, 1712-0118-04 | Pre-filter, carbon, H13 HEPA | About 12 months | None |
| Coway Airmega Mighty | Standard Filter Set, 3109689 | Carbon (deodorisation) filter and GreenHEPA | HEPA 12 months, carbon 6 (8 hours a day, top speed) | Pet set 3119912, Allergen set 3119914; washable pre-filter 3112965 |
| Coway Airmega 150 | Filter Set, 3109700 | Carbon filter and GreenHEPA | 12 months (8 hours a day, speed 2) | Pre-filters in three colours: 3107669, 3108292, 3109555 |
| IQAir HealthPro 250 | PreMax 102.10.10.00, V5-Cell 102.18.10.00, HyperHEPA 102.14.14.00 | F8 pre-filter; carbon and alumina gas filter; H12/H13 HyperHEPA | 12–18, 15–21 and 36–48 months (12 hours a day, speed 3) | Three-filter bundle; optional PF40 coarse-dust pads |
| Shark NeverChange5 HP150UK | HE15FKPET | HEPA with about 90 g of carbon | Up to 5 years (Shark’s own test) | Anti-odour cartridges about every 3 months; washable mesh dust filters |
| Tower T673000 | T67300001 | Pre-filter, carbon, H13 HEPA | About 6 months (1,500 hours) | Fits both colours |
| Meaco Arete One 20L and Arete Two 20L | MeacoDryArete20L/25LHepaFilter, pack of 3 | H13 HEPA | About 3 months, or when it turns grey | Charcoal pack AreteCharcoal20L/25L, fitted instead of the HEPA |
| Meaco Arete One 10L | MeacoDryArete10L/12LHepaFilter, pack of 3 | H13 HEPA | About 3 months, or when it turns grey | Charcoal filter AreteCharcoal10L/12L, instead of the HEPA |
| Meaco Arete One 6L | SD-AreteHepa-6L, pack of 3 | H13 HEPA | About 3 months, or when it turns grey | Charcoal pack SD-AreteCharc-6L, instead of the HEPA |
| Dyson Purifier Cool PC1 | Not published in what we could read | Glass HEPA and carbon, combined | Not stated; the screen and app show filter life | Check the part with Dyson by serial number |
| Dyson Purifier Hot+Cool HP1 | 965432-01 | Glass HEPA and carbon, combined; not washable | Not stated; the screen and app show filter life | Also listed for eleven other Dyson models |
| Dyson Humidify+Cool PH2 De-NOx | Not published in what we could read | H13 HEPA and carbon, plus a catalytic layer | The screen and app say when | Check the part with Dyson by serial number |
| Dyson Big+Quiet Formaldehyde | Not published in what we could read (HEPA and carbon are separate) | HEPA; carbon; permanent catalytic filter | The screen or app asks | Two filters to replace |
| Dyson HushJet Purifier Compact | Not published in what we could read | Electrostatic (not a classed HEPA), with carbon inside | Electrostatic about 5 years at 12 hours a day; carbon when prompted | Two filters to replace |
Filters are often shared: the FY2200 fits three Philips models, the Core 300-RF fits the Core 300 and 300S, and Dyson’s 965432-01 is listed for eleven Dyson models besides the HP1. Look-alikes aren’t: Blueair’s 3250i and 3450i take different filters, and Blueair says each fits its own model only. For the four Dyson models with no part number in anything we could read, check with Dyson using the serial number before you buy.
How often to change it
A maker’s interval is an average at a stated amount of use. Philips calls the AC2220’s three years a calculated average that dirtier air and longer running shorten. Others spell out the use:
- Coway: eight hours a day; IQAir: 12 hours a day on speed 3.
- Tower: about 1,500 hours, which it calls six months, or roughly eight hours a day. Round the clock, that’s about nine weeks.
- Shark and Dyson’s HushJet: up to five years (Shark) or about five (Dyson) at 12 hours a day, measured to the point where the clean air delivery rate (CADR) has halved.
So run a purifier harder than the maker assumes and the filter falls due sooner; Levoit says its light comes on sooner with heavy use. And a five-year figure marks the point where the filter cleans at half its starting rate, not the day it stops. The Department for Education’s ventilation guidance for schools says air cleaning units typically need a new filter every 6 to 12 months. For filters a year next to electricity, see what an air purifier costs to run.
The Philips AC2220 stands out: Philips puts its single FY2200 filter at about three years, against six to eight months for Levoit’s Core 300 filters and about a year for most Philips, Winix and Coway models.
What the filter light counts
On most purifiers the filter light is a clock, not a sensor. Levoit’s manuals say the reminder is based on how long the purifier has run, and IQAir’s monitor counts hours at each fan speed. App estimates add inputs: Blueair’s RealTrack uses fan speed, running hours and pollution levels. Nothing we read describes a sensor that checks the filter itself, so treat the light as an estimate. Philips goes further: on the AC0650, AC2220, AC3220 and AC3420, ignore the replacement alert and the purifier locks until a new filter is fitted and the counter reset.
How to reset the filter light
Reset once the new filter is in, because the counter starts again from zero. Examples from the manuals:
- Levoit Core 300: hold the check-filter button for 3 seconds (on the Core 300S, the sleep button).
- Philips AC2220: hold both filter-reset buttons for 3 seconds, or use the Air+ app.
- Blueair Blue Max: hold the fan-speed button for about 15 seconds, until every light comes on.
- Winix: on the T500, press the recessed reset button with a paper clip for 5 seconds; on the T800, hold the filter button for 5 seconds until it beeps.
- Dyson PC1 and HP1: hold Night mode on the remote until the five-second countdown ends.
Changed a filter early? Philips, Coway and Levoit use a different sequence for that; on the AC2220, for instance, you hold the reset buttons within 15 seconds of plugging back in.
Clean the pre-filter, never wash the HEPA layer
The outer pre-filter catches hair, lint and larger dust before the main filter, and makers set short intervals for it:
- Coway: vacuum or wash it every 2 to 4 weeks, and let it dry completely.
- Levoit and Winix: brush or vacuum it every 2 to 4 weeks (Levoit) or 14 days (Winix); never wash it.
- Blueair: the fabric outer pre-filter is washable.
- Shark: brush the mesh dust filters or rinse them in room-temperature water, then dry them for 12 hours.
- Meaco: clean the Arete’s dust filter at least every two weeks; Meaco says skipping it could invalidate the warranty.
The main filter is different. Nothing we read for our 26 models calls a HEPA layer washable, and Coway, Winix, Shark, Philips and Dyson say plainly that theirs must not be washed. Levoit says not to clean the main or carbon layers at all. Philips has you vacuum the surface of its combined filters when the cleaning alert shows, and Meaco allows a light vacuum of its HEPA filter between changes.
Pet, odour and allergen versions
Where makers sell versions, the difference is mostly the carbon layer, which deals with smells and gases; the US EPA notes that a purifier without a sorbent such as activated carbon won’t remove gases at all. Levoit sells Pet Allergy and Toxin Absorber versions of the Core 300-RF, with stronger carbon aimed at pet and cooking smells, or smoke, fumes and VOCs. The Levoit Core 300S and Core 300 take them all.
For the Coway Airmega Mighty, the Pet and Allergen sets hold two carbon filters and one GreenHEPA: a year’s worth on Coway’s cycle of carbon every six months and HEPA every 12. The standard set holds one of each, so its carbon filter is due halfway through the HEPA’s year.
Meaco’s charcoal filter fits instead of the Arete’s HEPA filter, not with it: Meaco says HEPA traps particles but not smells, and charcoal the reverse, so you swap by season or problem.
Genuine or compatible: what each maker says
We haven’t tested any compatible filters, so we can’t say whether one performs like the original. This is what the makers’ own documents say:
- Philips: use only original Philips filters made for that purifier; with any other, it can’t guarantee filtration (AMF870).
- Levoit: its filter-life tracking assumes genuine filters, and non-genuine ones may delay replacement, lower air quality and damage the motor. The warranty doesn’t cover repairs using non-Levoit parts.
- Coway: use genuine filters to keep performance up; the warranty excludes damage from parts Coway hasn’t approved.
- Meaco: non-genuine components void the five-year Arete warranty.
- Shark: use only Shark-branded filters; damage from non-Shark parts may not be covered.
- IQAir: use only filters and accessories the manufacturer recommends.
- Blueair: the warranty holds only if the filter is replaced on Blueair’s schedule, so keep proof of purchase.
- Winix, Tower, Dyson: Winix’s UK documents say nothing either way; we found no Tower manual and couldn’t read Dyson’s position.
The one independent check we found is American: AHAM Verifide, which verifies CADR claims, now tests replacement filters to confirm they perform like the original, and warns that unverified compatible filters may fall short on airflow or particle removal. We haven’t checked its list for UK models. Fit matters too: the UK’s SAGE-EMG paper on air cleaners reports some units cleaning far less than claimed because of poor manufacture or badly fitting filters, and asks for no leaks around the filter.
Of the 60 Coway Airmega Mighty owner reviews and posts we read, almost all from US owners of the same AP-1512HH model, three speak well of cheaper third-party sets and one finds the genuine sets pricey. Owners can judge fit and smell, not fine-particle capture, so that doesn’t settle it.
Why a clean-looking filter can still be due
HEPA filters are rated on particles of about 0.3 microns, the size that slips through most easily (US EPA), far smaller than dust you can see. So a filter’s colour says little about the fine particles it holds, and nothing about its carbon layer. Watch for the signs makers name instead: louder running, weaker airflow, a clogged filter or smells coming back (IQAir, Levoit, Coway). Meaco is the exception, telling owners to change the Arete’s HEPA filter when it turns from white to grey.
Getting rid of old filters
IQAir says used filters can normally go in household waste, unless the purifier may have filtered hazardous substances. Meaco says its larger Arete HEPA filters aren’t recyclable. When you replace the purifier itself, a shop selling you a like-for-like new one must take the old one back free under the WEEE rules.
Choosing a purifier with filters in mind? See the best air purifiers in the UK or compare every air purifier we track.
Replacement filter questions
How often should I change my air purifier filter?
Follow your model’s interval: about three months for Meaco’s HEPA refills, six to eight months for Levoit’s Core 300 filters, about a year for most Philips, Winix and Coway filters, and about three years for the Philips AC2220. These are averages at a stated daily use, so longer running or dirtier air brings the date forward.
Can I wash a HEPA filter?
No, unless the maker says so, and nothing we read for the 26 models we track does. Coway, Winix, Shark, Philips and Dyson say their main filters must not be washed. You can usually vacuum or brush the outer pre-filter, and Coway’s and Blueair’s can be washed; Coway says to let it dry completely before refitting it.
Are compatible filters as good as genuine ones?
We can’t say, because we haven’t tested any. Philips, Levoit, Coway, Shark, IQAir and Meaco tell owners to use their own filters, and Levoit, Coway, Shark and Meaco limit or void warranty cover where non-genuine parts are involved. In the US, AHAM Verifide tests replacement filters against the original and warns unverified ones may fall short.
Do I need to reset the filter light?
Yes, after fitting the new filter. On most models the light counts running time, so it only starts again when you reset it, usually with a long press: 3 seconds on Levoit’s Core 300 and Philips’ reset buttons, about 15 seconds on Blueair’s fan button. If you changed the filter early, check the manual for a different sequence.
Why has my Philips purifier stopped running?
Check the filter first. On the AC0650, AC2220, AC3220 and AC3420, Philips’ filter lock stops the purifier if the replacement alert is ignored, until a new filter is fitted and the counter reset. Fit the filter and hold the reset button or buttons for about 3 seconds. On the AC3220, also check the front cover is fitted properly.
