HVAC Filter Change Log Template

It is the maintenance record that lists every air filter on a property — where it is installed, its size and MERV rating, when it was last replaced, and when it is due next. Technicians use it so nothing gets missed between visits, and building owners use it as proof that filtration was maintained under a service agreement or a commissioning requirement.

It depends on the filter, not the calendar. Carrier publishes 30 days for a 1-inch fiberglass filter, 30 to 90 days for a 1-inch pleated filter, and 6 to 12 months for a 4-inch media filter — the thicker the disposable filter, the less often it needs changing. Pets, allergies, construction dust, and runtime all shorten those figures. This template starts each row at the published default for its filter type and lets you type over it, then works out the next due date for you.

Because filters are sold by nominal size. A 16x25x1 physically measures about 15.5 x 24.5 x 0.75 inches. The half inch is deliberate — cut to the nominal size the filter binds going into the track, and cut any looser and air bypasses the media entirely. Order by the nominal size printed on the frame, but measure the actual one before you assume a replacement will seat. This template converts nominal to actual automatically, and tells you when a depth is one it cannot verify.

ASHRAE 62.1 section 5.9 sets the floor: a MERV of not less than 8 upstream of every cooling coil or other wetted surface through which air is supplied to an occupiable space. Under ASHRAE 52.2, MERV 8 must capture at least 70 percent of 3 to 10 micron particles; MERV 11 adds 65 percent at 1 to 3 microns and 20 percent at 0.3 to 1 micron; MERV 13 reaches 85 and 50 percent in those bands, which is why it is the level most infection-control strategies are built around. ASHRAE 241 sets its mechanical-filter floor at MERV-A 11 or equivalent. Going higher than the equipment can breathe is its own problem — check the static pressure before you upgrade.

Because it is the observation the customer is actually paying for, and it is the one that builds a case over time. A filter logged as loaded at every visit says the interval is too long or the property is dirtier than assumed — that is a media-cabinet conversation backed by your own records rather than an opinion. It is also what a building owner points at when a warranty claim asks whether filtration was maintained. This log records the condition coming out and going in on every entry, and keeps every entry.

Yes — that is the point of it. Each filter position keeps a running history, and every visit adds a line rather than overwriting the last one. The next due date is always read from the newest entry, so the schedule stays right while the history stays intact. Most free filter templates give you a single "last changed" box per filter, which means next quarter you type over the only record you had.

Yes. Build and download it free as a PDF, Excel, or Word file — no login. Add as many filter positions as the property has and customize the intervals for your typical equipment.