| ▲ | schiffern 3 hours ago | |
Agreed. MERV 11-14 can be far more effective than HEPA. If you need to filter "one and done" (like pumping air into a hospital operating room), that's where you need HEPA. Most home air purifiers mix the clean air back into the same room, so MERV is closer to the ideal sweet spot. It's also important to buy reputable brands of MERV filter, ideally ones which have a large number of folds (surface area) like the 3M 1900 MPR. In recent testing about half of filter brands scored well below their claimed MERV rating: | ||