Trane Air Filters: Sizes & Replacements
Quick answer: Trane furnaces and air handlers without a media cabinet take standard 1-inch filters at the return — measure the slot and find your size. Trane Perfect Fit cabinets (BAYFT series) use nonstandard footprints like 17.5x27 and 21x27; we don't stock those, and a standard-size filter won't seal in them — use the BAYFT part on the cabinet door.
Trane model directory
| Model / part | Filter size & fit | Guide |
|---|---|---|
| Standard return slot | Common sizes: 16x25x1, 20x25x1, 14x20x1 | Replacement guide |
| Perfect Fit (BAYFT) | Nonstandard cabinet media — check cabinet door, not stocked here | — |
Trane filter FAQ
What size filter does a Trane furnace take?
Without a media cabinet, Trane systems take standard 1-inch nominal sizes at the return — check the size printed on your old filter or measure the slot. 16x25x1 and 20x25x1 are the most common.
Do you sell Trane Perfect Fit replacement media?
No — Perfect Fit cabinets use nonstandard footprints (17.5x27x5, 21x27x5 and similar) and only the BAYFT-series media seals correctly. If your cabinet takes one, buy the OEM part. For everything else, we’ve got you.
What MERV rating works in a Trane system?
MERV 8–13 in standard 1-inch slots depending on your air: 8 for dust, 10–12 for pets and allergies, 13 for smoke season. Change 1-inch filters every 90 days.
Every Ironside filter is American-made by our manufacturing partners. Flat-rate shipping — same on 1, 2 or 3 packs. Built here. Breathe better.