Buying guide · Air purifiers
The best air purifiers for allergies and asthma triggers
Our top picks: the Coway Airmega AP-1512HH Mighty, the Levoit Core 400S and the Levoit Core 300S. Pollen, dust-mite debris and pet dander are particles a HEPA filter catches well, so a properly sized HEPA purifier lowers how much of them is in a room's air.
It works best in the room where you spend the most time, usually the bedroom, run continuously with the windows closed during pollen season.
Updated · 5 picks · figures from AHAM, Energy Star, NIOSH and the makers · no brand pays to be listed
| Purifier | Smoke CADR | Everyday room | Smoky days | Quietest | Filter | Price |
|---|---|---|---|---|---|---|
| Coway Airmega AP-1512HH Mighty | 233 cfm | 34 m² (361 ft²) | 22 m² | 24.4 dB | $59.79up to 1 year | $239.99at cowaymega.com |
| Levoit Core 400S | 231 cfm | 33 m² (358 ft²) | 21 m² | — | $49.99 | $189.99at levoit.com |
| Levoit Core 300S | 141 cfm | 20 m² (219 ft²) | 13 m² | 22 dB | $29.99every 6–8 months | $149.99at levoit.com |
| Blueair Blue Pure 211i Max | 435 cfm | 63 m² (674 ft²) | 40 m² | 23 dB | — | $349.99at blueair.com |
| Honeywell HPA300 | 300 cfm | 43 m² (465 ft²) | 28 m² | — | $89.95 | $269.95at honeywellstore.com |
Everyday room: AHAM's room size for the smoke CADR (about five clean-outs an hour). Smoky days: AHAM's stricter advice for smoke, a CADR at least equal to the floor area in square feet. Quietest: the maker's figure for its lowest setting. Filter: the replacement's list price at its maker.
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Best overall
Coway Airmega AP-1512HH Mighty
The proven all-rounder for a bedroom or living room of about 34 m².
- Cleans
- 34 m² day to day, 22 m² on smoky days
- Quietest
- 24.4 dB
- Filter
- $59.79, up to 1 year
$239.99at cowaymega.com
Shows PM2.5
Levoit Core 400S
No ionizer at all, and a live PM2.5 readout to show it working.
- Cleans
- 33 m² day to day, 21 m² on smoky days
- Filter
- $49.99
$189.99at levoit.com · sale price, was $219.99
Smart bedroom
Levoit Core 300S
For a bedroom: auto mode raises the fan when particle levels rise.
- Cleans
- 20 m² day to day, 13 m² on smoky days
- Quietest
- 22 dB
- Filter
- $29.99, every 6–8 months
$149.99at levoit.com
Most clean air
Blueair Blue Pure 211i Max
For a large living room, with a washable pre-filter.
- Cleans
- 63 m² day to day, 40 m² on smoky days
- Quietest
- 23 dB
$349.99at blueair.com
No-frills power
Honeywell HPA300
A simple, strong HEPA purifier for a bigger room.
- Cleans
- 43 m² day to day, 28 m² on smoky days
- Filter
- $89.95
$269.95at honeywellstore.com
What size do you need?
The single biggest mistake is a purifier too small for the room. Type yours in to see the clean air it needs, and which picks get there.
You need a smoke CADR of at least 108 cfm (your room is about 161 ft²).
On this list: Coway Airmega AP-1512HH Mighty, Levoit Core 400S, Levoit Core 300S, Blueair Blue Pure 211i Max, Honeywell HPA300.
The rule is AHAM's, the US body that certifies CADR ratings: two-thirds of the floor area in square feet day to day, the full floor area for smoke. It assumes an 8 ft (2.4 m) ceiling; for a higher one, aim a little above it.
How we chose
True HEPA
A HEPA filter, not an 'HEPA-type' one, with the CADR verified by AHAM or Energy Star.
Sized right
A purifier too small for the room barely changes its air; each pick shows the room it covers.
No ozone
Ozone irritates airways, so no ozone-producing ionizers; switch-off ionizers are noted.
We haven't lab-tested these ourselves. The rankings rest on independent ratings (AHAM's verified CADR, Energy Star's listings, NIOSH approvals) and the makers' own figures, each shown on the product's page with where it's from. No brand pays to be listed, and the order doesn't change with commission. We earn a small commission when you buy through our links.
Questions
- Do air purifiers help with allergies?
- They reduce airborne allergens such as pollen, dust and dander in the room they run in. They don't remove allergens that have settled, so vacuum and wash bedding too.
- What is a True HEPA filter?
- A filter that captures at least 99.97% of particles at 0.3 microns, the hardest size to catch. 'HEPA-type' or 'HEPA-like' filters don't meet that standard.
Before you buy
Check how bad the air gets where you live
A purifier matters most where the air is often unhealthy. See today's reading and the past week for your city, from the nearest ground stations.