The 4 Best Large Room Air Purifiers - Fall 2024

The NuWave OxyPure is the best air purifier for large rooms we've tested. This premium model provides a very high clean-air delivery rate, making it an efficient option in larger spaces. This isn't even its main selling point—the unit's advanced multi-stage filtration system is. Unlike many other air purifiers, which have disposable filters you must replace periodically, the NuWave uses primarily washable parts to reduce ownership costs. This system comprises a stainless steel mesh pre-filter for larger debris, two 'Bio-Guard' filters (for mold, viruses, and bacteria), an ozone filter, and a combined HEPA/pellet-type activated carbon filter. Except for the HEPA/activated carbon filter, which you'll need to replace once a year, the rest have an advertised 20-year lifespan. In fact, they only require a wash every couple of months.

This air purifier has built-in particle sensors that allow it to monitor ambient air quality and change the fan speed accordingly, so babysitting it is unnecessary. It's also Wi-Fi enabled, so you can operate it remotely using the NuWave Connect companion app. The app lets you check the quality of your home's air while you're away, set operating schedules, or change the device's settings. It operates pretty quietly at lower fan speeds, but it can get loud at higher fan speeds, which is something to note if you have it set up in a living room or bedroom.

On the other hand, if you need an air purifier for a large space that isn't being lived in, like a workshop or an unfinished basement, consider building your own Corsi-Rosenthal Box. We used this guide to make our own and used a 3M Filtrete air filter set with a Lasko 20-inch box fan. This homemade option obviously lacks quality-of-life features, especially compared to a high-end device like the NuWave OxyPure. There's no particle sensor, Wi-Fi connectivity, or odor-absorbing carbon filter. The latter omission isn't a big deal since most air purifiers with carbon filters we've tested don't contain enough of the material to deal with even moderate levels of volatile compounds effectively. The large box fan is rather noisy, too. Some users have iterated on the design using multiple compact PC fans instead of a single large box fan to draw in air, with the aim of cutting down on noise and energy consumption, though we haven't built such a unit yet and can't verify if it'll perform similarly.

This basic iteration of a Corsi-Rosenthal Box handily outperforms most other consumer air purifiers on the market, with a sky-high clean air delivery rate and exceptional particle filtration. However, you'll need to dispose of the filters at the end of their useful lifetime; depending on how often you use the unit, that can be as little as three months, which means it incurs a higher financial and time investment in the long run compared to most conventional consumer units.

Check out the Honeywell HPA300 if you want something a little less expensive. It isn't nearly as sophisticated as the much pricier NuWave Oxypure, sporting a comparatively basic two-stage filtration system that comprises a carbon pre-filter sheet for trapping odors and three separate HEPA filters, and unlike the NuWave, these filters aren't washable. That said, not only is it much cheaper, to the point where you could easily afford two of these units for the same price as a single NuWave, but its performance is also fantastic. Its clean-air delivery rate is more than a match for the pricier model, making it a wonderful option for larger homes.

Unfortunately, while it's quieter than the DIY Corsi-Rosenthal Box, it's certainly louder than most other options at its lowest fan speed, so it might not be the best choice for bedrooms and the like. It lacks Wi-Fi connectivity, too, so you can't operate the unit while you're away from home. If that's a must-have feature, the Levoit Core 600S is a smart option with only marginally lower clean air delivery rate, though it's normally only available at a higher price point.

The best air purifier for large rooms we've tested at a budget price point is the Winix 5500-2. This air purifier can't quite compete with higher-end models like the Honeywell HPA300 or the NuWave OxyPure for raw clean air delivery rate, so it won't clear particulates from the air quite as quickly in bigger spaces. That said, given its relatively affordable price point, its overall performance is nothing to sneeze at. It does a great job of trapping small airborne allergens thanks to a multi-stage filtration system with a HEPA-rated main filter, a washable mesh pre-filter, and a carbon filter.

The Winix also has a particle ionizer; these systems impart a negative charge to airborne particles, drawing them together into larger clumps that fall onto surfaces so you can clean them up later. Ionizers produce ozone as an operating byproduct, though, which can be a lung irritant if you're exposed to it for prolonged periods, so it's good that you can turn the Winix air purifier's ionizer off. While the 5500 has a built-in air quality sensor that adjusts its fan speed in real time depending on ambient particle levels, it lacks Wi-Fi connectivity for remote operation. If that's a must-have feature, the Levoit Vital 200S is a good alternative with a similar clean air delivery rate. However, its main filter technically lacks HEPA certification.