Filter ratings measure how small a particle a filter catches. The higher you go, the more your blower has to push.

MERV 13 in a media cabinet

A 4 or 5 inch MERV 13 cabinet catches most pollen, dust and smoke particles without hurting airflow. It suits most homes we see.

When HEPA is worth it

For severe allergies or asthma, a bypass HEPA unit cleans part of the air stream to hospital grade. It costs more, but your main blower stays happy.