If you're looking for something that strikes a great balance between performance and features, the best air purifier we've tested is the NuWave OxyPure. This premium model's main selling point is its multi-stage filtration system, which uses washable and reusable filters instead of replaceable ones. 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 HEPA/pellet-type activated carbon filter. Except for the HEPA/activated carbon filter, which needs replacing every year, the manufacturer states that these parts have a 20-year lifespan, only requiring a wash every couple of months. In terms of actual air purification performance, the NuWave is also very good overall, with good particle filtration performance across the board and an impressively high clean air delivery rate. Its built-in particle sensors allow it to monitor and change fan speed according to ambient air quality.

This air purifier is also Wi-Fi enabled, and you can operate it remotely using the NuWave Connect companion app, letting you check the quality of your home's air while you're away, set cleaning schedules, or change the device's settings. It also operates pretty quietly at lower fan speeds, which is good if you leave it running overnight, but it can get pretty loud at higher fan speeds; check out the Dyson Purifier Big+Quiet Formaldehyde BP04/BP03 if that's a major concern, but be aware that it falls short of the NuWave in both small particle filtration performance and clean air delivery rate.