Coway Airmega 400 vs Blueair Blue Signature Large

The Blueair Blue Signature Large is a better air purifier than the Coway Airmega 400, though the gap between them is fairly small. The Blueair delivers somewhat stronger particle filtration, holds onto more of that performance at quieter fan speeds, and is quieter overall. It also adds smartphone app connectivity and a more considered design, with a furniture-inspired form factor that lets it double as a small side table and blend into a living room or bedroom more naturally than the Coway. Unlike the Blueair, which relies in part on HEPASilent ionization to achieve its performance numbers, the Coway uses purely mechanical filtration and doesn't produce ozone as a byproduct, making it a better choice if you or your pets are sensitive to ozone.