Filters are the running cost of a purifier, and a few cheap tools handle what a purifier can’t reach: settled dust, damp walls and allergens in bedding.
Buy genuine filters for the purifier you own and set a reminder for the filter’s rated life. Add a laser PM2.5 monitor to see whether the purifier keeps up, a hygrometer for damp rooms, and zippered covers for allergy beds. For pet hair and settled dust, a sealed HEPA vacuum does what no purifier can.
| If you need | Start with | Why |
|---|---|---|
| Mighty2 owners | Coway Max2 filter | Genuine 2-in-1 filter, up to a year |
| HPA120 or HPA125 owners | Honeywell O filter | 9 to 12 months |
| Is the purifier keeping up? | Temtop S1 monitor | Laser PM2.5 sensor |
| Damp rooms | Govee hygrometer | About ±3% RH, app alerts |
| Allergy bedding | Zippered pillow protectors | Zippered covers |
| Settled dust and pet hair | Bissell sealed-HEPA stick vacuum | Sealed HEPA |
Sometimes, but you can’t tell from the listing. The fit and the seal decide whether air goes through the filter or around it, and some filter-life indicators only work with genuine filters.
From the listings: Levoit says its filter-life indicator only works with authentic filters, and Dyson says third-party filters may not seal properly.Follow the indicator or the rated life, whichever comes first, and change sooner in smoke season. If airflow drops or a smell returns, it is time.
Rated lives here: Coway Max2 up to 1 year, Honeywell O 9 to 12 months, Levoit EverestAir-P 12 to 15 months, GermGuardian B 6 months.Yes, as a pre-filter layer you trim to fit, and it helps with mild smells. Keep it thin enough not to choke airflow, and replace it about every three months.
About 3 months: the replacement interval the carbon sheet maker suggests.These questions come from Bing searches on this topic and from what testers measure. We summarize; we don’t run our own lab.
| Filter | Fits | Rated life | Per year |
|---|---|---|---|
| Coway Max2 filter | Coway Airmega Mighty2 (AP-1512N) | Up to 1 year | About $49 a year per filter slot. |
| Honeywell O filter | Honeywell HPA120 and HPA125 | 9 to 12 months | About $35 to $47 a year per filter slot. |
| EverestAir-P filter | Levoit EverestAir-P | 12 to 15 months | About $37 to $46 a year per filter slot. |
| Honeywell filter R | HPA094, HPA100, HPA200, HPA250, HPA300 and other HPA series | Replace yearly | About $9 a year per filter slot. |
| Winix filter H | Winix 5500-2 (check your model label) | One year | About $36 a year per filter slot. |
| GermGuardian filter B | AC4300, AC4825, AC4850PT, AC4880, AC4900 and more | 6 months (carbon layer 2 to 3) | About $33 a year per filter slot. |
| Dyson 360 filter | Dyson TP04, HP04, TP07, HP07, TP09, HP09 and others on the label list | 12 months | About $79 a year per filter slot. |
Yearly costs are rounded from Amazon listings checked on October 24, 2026. Filters whose price failed our checks show no cost. Check today’s price before you order.
Genuine 2-in-1 HEPA and carbon filter for the Mighty2. Coway also sells Intense Smoke and Allergen versions of the same filter.
What to look for: the AP-1512N model code; it doesn’t fit the older AP-1512HH.
Fits: Coway Airmega Mighty2 (AP-1512N). Life: Up to 1 year. About $49 a year per filter slot.
Pre-filter, HEPA and carbon in one piece; vacuum the pre-filter to stretch its life.
What to look for: the O letter code; HPA120 and HPA125 share it.
Fits: Honeywell HPA120 and HPA125. Life: 9 to 12 months. About $35 to $47 a year per filter slot.
Main filter plus activated carbon; the washable pre-filter stays and gets rinsed every 2 to 4 weeks.
What to look for: a genuine filter so the filter-life indicator keeps working.
Fits: Levoit EverestAir-P. Life: 12 to 15 months. About $37 to $46 a year per filter slot.
Larger HPA models take one to three R filters, so a 3-pack lasts one to three years.
What to look for: how many R filters your model holds; bigger HPA units take two or three.
Fits: HPA094, HPA100, HPA200, HPA250, HPA300 and other HPA series. Life: Replace yearly. About $9 a year per filter slot.
True HEPA plus an odor-control carbon filter. The listing names the 5500-2; confirm it fits before buying for a 5510.
What to look for: the model printed inside your Winix before ordering.
Fits: Winix 5500-2 (check your model label). Life: One year. About $36 a year per filter slot.
HEPA PURE media with a pet treatment and a carbon pre-filter.
What to look for: your model in the compatibility list; carbon wears faster than the HEPA.
Fits: AC4300, AC4825, AC4850PT, AC4880, AC4900 and more. Life: 6 months (carbon layer 2 to 3). About $33 a year per filter slot.
Genuine Dyson replacement; Dyson says third-party filters may not seal properly.
What to look for: the model code on the sticker under your Dyson.
Fits: Dyson TP04, HP04, TP07, HP07, TP09, HP09 and others on the label list. Life: 12 months. About $79 a year per filter slot.
Coconut-shell activated carbon you trim to size, for litter-box or smoke smell. Use the old sheet as a template.
What to look for: a sheet big enough to trim to your pre-filter slot.
Fits: Cut to fit pre-filter slots. Life: About 3 months.
Actual size 19.5 x 19.5 x 0.75 in. Check your system can handle MERV 13 airflow before switching.
What to look for: the size printed on your current furnace filter.
Fits: HVAC returns and DIY box-fan purifiers. Life: About 90 days.
Laser PM2.5 sensor with AQI, temperature and humidity on one screen, and up to 60 days per charge.
What to look for: a laser PM2.5 sensor rather than a basic dust sensor.
Humidity accurate to about plus or minus 3% RH, with app alerts and two years of exportable history.
What to look for: accuracy of about ±3% RH and alerts.
A basic humidity readout, accurate to about plus or minus 5% RH, with dry, comfort and wet faces.
What to look for: a clear readout if you don’t need an app.
Tightly woven zippered covers that keep allergen particles from collecting inside the pillow.
What to look for: a full zipper and a tight weave.
Six-sided zippered cover for queen mattresses up to 15 inches deep, waterproof and machine washable.
What to look for: six sides and a depth range that fits your mattress.
Cotton terry top, six-sided zippered seal, GREENGUARD Gold certified, with a 10-year quality guarantee.
What to look for: a sealed zipper end if bed bugs are also a concern.
Stick-on silicone sweep that closes the gap under a door, which keeps smoke and dust from drifting in.
What to look for: a length that matches your door width; trim the rest.
Rolls hair off couches and bedding into a built-in bin, with no sticky refills.
What to look for: a bin you can empty, with no sticky refills.
Removes 50 pints a day at the test condition (90°F, 80% RH), holds a humidity target, and runs nonstop with the 6.6 ft hose.
What to look for: a humidity setpoint and a drain hose for nonstop running.
Set a target humidity and let it cycle; the filter rinses clean.
What to look for: a pint rating that fits the room.
A plain 20-inch, 3-speed box fan, the base for a DIY box-fan purifier with a MERV 13 filter.
What to look for: a 20-inch square frame for a DIY filter build.
Sealed HEPA system, a tangle-free brush roll for pet hair, a 27 ft cord and an 8.5 lb body that converts to a handheld.
What to look for: a sealed HEPA system, not just a HEPA filter.
Most combined HEPA and carbon filters last 6 to 12 months. Check your model’s rated life in the table above, and change sooner in smoky or smelly homes.
No. Washing ruins HEPA media. Pre-filters and permanent electrostatic filters, such as Honeywell’s ifD, are made to be rinsed.
Not to run a purifier, but it tells you whether the purifier keeps up and when smoke has cleared. Choose one with a laser PM2.5 sensor.
MERV 13 if your system can handle the airflow. It catches much more fine dust and smoke than a basic filter.
Yes. Mite allergen sits in bedding, and zippered covers on the mattress and pillows keep it sealed away.
Match the pint rating to the space and how damp it is, and choose one with a hose outlet for basements so it can run nonstop.