My son has some lung problems and is sensitive to dust and smoke. I recently decided to get HEPA filters for the 3 bedrooms and replace the decade+ old Holmes

My son has some lung problems and is sensitive to dust and smoke. I recently decided to get HEPA filters for the 3 bedrooms and replace the decade+ old Holmes unit that was starting to look worse for the wear and I had been using in the kitchen while I was remodeling. I ended up going with the Coway unit the Wirecutter recommends and have been pretty happy with it. One nice feature that seems to work pretty well is that it has a particulate sensor and an "auto" mode that adjusts the speed based on particulates in the air. The normal mode is super quiet, but when it detects gunk (often triggered by walking into the room), it will kick up the fan for a bit. I don't always love the Wirecutter/Sweethome choices, but in this case it directed me to a product I wasn't even considering and I was happy with it. Always read the details of the reviews, what they find important may not match what you do.