Enter your ZIP code for a live AQI reading (via AirNow) and a filter rating recommendation based on current conditions.
MERV 13 is the rating most commonly recommended (including by the EPA's wildfire smoke guidance) for capturing the fine particulates (PM2.5) that drive AQI up during smoke events. Not every HVAC system can handle MERV 13 without airflow issues — check your system's manual or ask an HVAC technician before upgrading.
True HEPA filtration is rarely used in central HVAC systems — the standard residential blower usually can't push enough air through media that dense. MERV 13 in your existing HVAC system plus a portable HEPA air purifier in the rooms you spend the most time in is the practical combination most guidance recommends for smoke events.
Daily is reasonable during an active wildfire or smoke event, since AQI can shift quickly — the live reading above pulls current data for your ZIP code from AirNow, the same source used elsewhere in this app.