The 4 Best Air Purifiers For Allergies - Fall 2024

The Honeywell HPA300 is the best air purifier for allergies we've tested, especially for large rooms. Sporting a two-stage filtration system that comprises a carbon pre-filter sheet for trapping odors and three separate HEPA filters, it provides a remarkably high clean-air delivery rate and does a fantastic job of trapping the smallest airborne allergens, including cat dander and pollen. Unfortunately, the filters aren't washable—the carbon filter lasts three months, while the HEPA filter lasts 12. This is a relatively simple device that lacks Wi-Fi connectivity, so remote operation is out of the question, and there's also no particle sensor to monitor allergen levels in real-time.

If a particle sensor is a must-have feature, the Levoit Core 600S is a good alternative, though its clean air delivery rate is a little lower. Alternatively, if you don't mind spending a lot more on a smart unit that makes much less noise, you could also consider the Dyson Purifier Big+Quiet Formaldehyde BP04/BP03. Just be aware that despite its large footprint and high price, its clean air delivery rate is also less than that of the comparatively humble Honeywell.

If you're sensitive to allergies but don't mind getting your hands dirty, consider building your own Corsi-Rosenthal Box. We built our own by following this guide, which combines a quartet of MERV 13 3M Filtrete air filters with a Lasko 20-inch box fan. It's a crude device, even compared to the relatively basic Honeywell HPA300: it has a large footprint, and its single large box fan makes a lot of noise while running. Some users have iterated on the initial design to resolve the noise issue by swapping out the single fan for multiple PC cooling fans, resulting in quieter operation and lower power consumption. We haven't built a Corsi-Rosenthal Box using this design yet.

You'll have to replace the filters once they've been fully used, which means buying a whole new set of filters and effectively rebuilding the entire unit. With all that said, this unit delivers exceptional overall particle filtration performance, trapping a wide variety of airborne allergens while providing a clean air delivery rate that's high enough for you to use this model in large spaces like workshops or garages.

Look at the Levoit Vital 200S if you have allergies but don't need as large a machine or don't want to pay as much for an air purifier. While its main filter technically lacks a HEPA certification, it does a fantastic job of trapping the smallest airborne allergens, ranging from dust to pollen to pet dander. However, its clean air delivery rate isn't as high as the Honeywell HPA300. Unlike that model, it has an onboard particle sensor, allowing it to adjust its fan speed in real-time based on current particle levels. It's also Wi-Fi enabled, so you can operate it through your smartphone using the Levoit VeSync companion app.

If you want a device with a HEPA-rated filter, the Winix 5500-2 is a good alternative. It provides similar overall performance and is roughly comparable in size. That said, unlike the Levoit, the Winix has a built-in ionizer. This system imparts a negative charge to smaller airborne particles, causing them to stick together and fall out of the air, where you can then dust or vacuum them away. Unfortunately, ionizers produce ozone as a byproduct, which can irritate your respiratory system. Thankfully, you can easily turn it off without affecting performance.

If you want an air purifier for smaller rooms, the Levoit Core 300 is another great option. Unlike the Levoit Vital 200S, it has no Wi-Fi connectivity or built-in air quality sensors, so you can’t monitor allergen levels from your phone. That said, it’s smaller overall, making it easier to fit in smaller rooms, and it still delivers good overall air purification performance. Its clean air delivery rate is considerably less than that of the Vital 200S, but it still performs quite well in trapping the smallest of airborne particles.

The Core 300 is also compatible with other Levoit filters meant to counteract more specific types of allergens. There's the 4-Stage Smoke Remover filter, the 3-Stage Toxin Absorber filter, and the 3-Stage Pet Allergy filter. We haven't yet tested the device with these filters, though we don't expect a massive performance differential across these filter types.