What type of filter do I need for allergies?

A True HEPA filter, ideally H13 grade, which captures 99.97% of particles 0.3 microns and larger including pollen, dust mite debris, and pet dander. Avoid units marketed only as "HEPA-type" or "HEPA-like", because those are not held to the same standard and are a common source of disappointing results.

What size air purifier do I need for a bedroom?

Match CADR to the room, aiming for a CADR roughly two-thirds of the room area in square feet for four air changes per hour. A bedroom up to about 350 sq ft is well served by a purifier like the Coway Airmega 200M or Levoit Core 300. Larger rooms need a bigger unit, and two smaller purifiers often beat one oversized one.

Do air purifiers actually help with pollen allergies?

Yes, indoors, when sized correctly and run continuously with the doors and windows closed. They significantly reduce airborne pollen and dust that comes in on clothing and through gaps. A purifier cannot help if windows are open or if the unit is undersized for the room.

Should I run an air purifier 24/7?

For allergies, yes - run it continuously, using a higher fan speed when you are not in the room and a low, quiet setting at night. Cycling it only when symptoms flare is far less effective, because particle levels build back up quickly in a closed room.

Do I need an activated carbon filter for allergies?

Carbon does not filter allergens; it removes odors and VOCs such as cooking smells, smoke, and paint fumes. If those bother you alongside allergies, choose a model with a substantial carbon layer. For pollen and dander alone, True HEPA is the part that matters.

Are ionizers and UV-C lights worth it for allergies?

Mostly no. UV-C does little for airborne particles at the doses used in home units, and ionizers can produce trace ozone, which is itself a lung irritant and a bad idea for allergy sufferers. Stick to mechanical True HEPA plus activated carbon.

Best Air Purifiers for Allergies in 2026

Quick answer:

Best overall value: Coway Airmega 200M (~$229) – the best clean-air-per-dollar for bedrooms.
Best smart pick: Levoit Core 400S (~$219) – app scheduling and a real-time air quality readout.
Best for large rooms: Coway Airmega 400 or Levoit Vital 200S (~$300-$400) – 800+ sq ft.
Best budget bedroom: Levoit Core 300 (~$100) – True HEPA for a small room.
Skip: Dyson Big+Quiet (~$899) – excellent, but roughly four times the price for marginal gains.

What actually helps with allergies? Three things: a genuine True HEPA filter, a CADR matched to your room size, and running it continuously with windows shut. Everything else – ionizers, UV-C, “HEPA-type” labels – is noise.

How much should you spend? $200-$250 is the sweet spot: a real True HEPA filter, strong CADR, and affordable replacement filters. Above $400 you pay for design, smart features, or a built-in heater, not better cleaning.

First: Answer These 3 Questions

How big is the room? Bedroom up to about 350 sq ft: a Coway 200M or Levoit Core 300. Living room or open plan at 500-800+ sq ft: a Coway 400 or Levoit Vital 200S.
Particles or odors? Pollen, dust, and dander need True HEPA. Cooking smells, smoke, and VOCs also need a substantial activated carbon layer.
Will you sleep with it running? If yes, prioritize low noise. Look for under 30 dB on the low setting; some units run as quietly as 24 dB.

5 Checks Before You Buy

Check	Target	Plain English
True HEPA	H13 grade	Captures 99.97% of 0.3-micron particles; “HEPA-type” is not the same standard
CADR	~2/3 of room sq ft	Higher CADR cleans faster; match it to the room, do not oversize
Activated carbon	Substantial layer	Needed for odors and VOCs; HEPA alone will not remove them
Filter cost	$35-$40/year	The cheapest purifier can be the priciest to run
Noise	Under 30 dB on low	Determines whether you keep it running overnight

2026 Top Picks for Allergies (By Specs, Owner Reports & Price, Not Paid Placement)

Coway Airmega 200M – Best Overall Value

Price: ~$229 (often less on sale)
Why: The best CADR per dollar in the category: True HEPA plus activated carbon, rated for about 361 sq ft, and just 24 dB on low. In independent testing it dropped PM2.5 from 28 to 2 µg/m³ in 18 minutes in a medium room, and filters cost only around $35 a year.
Honest take: The right choice when allergy relief in the main bedroom is the goal. Downside: no app or smart features.

Levoit Core 400S – Best Smart Purifier

Price: ~$219
Why: True HEPA with app control, scheduling, real-time air quality readings, and voice assistant support. Rated around 260 sq ft, with the best app of any purifier in its class.
Honest take: Buy it if you want automation and data. Downside: smaller coverage than the Coway, a little louder on maximum, and filters run about $40 a pair.

Coway Airmega 400 / Levoit Vital 200S – Best for Large Rooms

Price: ~$300-$400
Why: Both handle open-plan spaces over 800 sq ft with high CADR and dual filters, so one unit can serve a living area instead of several small ones. The Coway 400 has held the benchmark spot for big rooms for years.
Honest take: Necessary for open-plan homes. Downside: bulkier and more expensive to keep in filters.

Levoit Core 300 – Best Budget Bedroom

Price: ~$100
Why: Genuine True HEPA filtration for a small bedroom at a budget price, with an optional carbon filter for odors, and quiet operation.
Honest take: A genuine HEPA option that fits a single small room. Downside: covers only about 200 sq ft, so it is not a whole-room solution for large spaces.

One-Line Decision Table

Your situation	Pick this
Best clean air per dollar, bedroom	Coway Airmega 200M
Want app control and live data	Levoit Core 400S
Large or open-plan room	Coway Airmega 400 / Levoit Vital 200S
Tight budget, one small room	Levoit Core 300

Sources & Data

This guide uses official specifications, published results from named review bodies and long-term owner reports. Featured sources (verified 2026-09-23):

ENERGY STAR Air Cleaners – official CADR and energy data
EPA Indoor Air Quality – EPA guidance on air cleaners, filters and allergens
EPA Air Cleaners & Filters – how filtration and coverage relate to room size
ENERGY STAR Refrigerators – official energy-efficiency ratings for home appliances
AHAM – appliance standards and certification

Table sizes, wattage and prices change; verify current specs at the manufacturer before you buy.

FAQ

What filter do I need for allergies? True HEPA, ideally H13, which captures 99.97% of particles 0.3 microns and larger. Avoid “HEPA-type” labeling.

How big a purifier for a bedroom? Match CADR to roughly two-thirds of the room’s square footage. Up to about 350 sq ft suits a Coway 200M or Levoit Core 300.

Do purifiers help with pollen allergies? Yes, indoors, when sized correctly and run continuously with windows closed.

Should I run it 24/7? Yes for allergies. Use a higher speed when out of the room and a quiet setting overnight.

Do I need activated carbon? Only for odors and VOCs. Pollen and dander are handled by True HEPA.

Are ionizers and UV-C worth it? Mostly no. UV-C does little for particles, and ionizers can emit trace ozone, which irritates lungs.

Real Pitfalls to Avoid

“HEPA-type” is not True HEPA – it is the most common cause of disappointing allergy results
Oversizing wastes money; match coverage to the room
Ignoring filter cost can double the real cost over a few years
Ionizers can produce ozone, which is bad for allergy and asthma sufferers
A purifier cannot fix a poorly ventilated room – it supplements, not replaces, fresh air

Part of our coverage: best air purifiers overall. See how we rank products.

Update note: refreshed quarterly. Prices checked Sep 2026, verify at checkout. Rankings based on published specifications, published review-body scores and long-term owner reports, not paid placement.