Honeywell Air Filters: Sizes & Replacements
Quick answer: Most Honeywell-equipped furnaces take a standard 1-inch filter at the return — measure the slot and find your size. Honeywell F100/F150 media cabinets take a 5-inch deep-pleat media instead: our "H" line is cut to that footprint (about 4⅜ inches deep).
Honeywell model directory
| Model / part | Filter size & fit | Guide |
|---|---|---|
| FC100A1029 | 16x25 media (F100F1025 / F25 cabinets) | Replacement guide |
| FC100A1037 | 20x25 media (F100F2025 / F150 cabinets) | Replacement guide |
| F100F2025 | 20x25 media cabinet — takes FC100A1037-size media | Replacement guide |
| F100F1025 | 16x25 media cabinet — takes FC100A1029-size media | Replacement guide |
Honeywell filter FAQ
What size filter does a Honeywell furnace take?
If the filter sits in a 1-inch return slot, it takes standard nominal sizes — measure the old filter or the slot. If you have an F100 or F150 media cabinet, it takes 5-inch deep-pleat media: FC100A1029 size for 16x25 cabinets, FC100A1037 size for 20x25.
Can I use a 1-inch filter in a Honeywell media cabinet?
No. The cabinet is about 4⅜ inches deep; a 1-inch filter leaves a gap and unfiltered air bypasses it. Use media cut to the cabinet footprint — our H line.
How often do Honeywell media filters need changing?
Every 6–12 months. The deep pleats hold roughly a year of dust in most homes; change sooner with pets or wildfire smoke.
Every Ironside filter is American-made by our manufacturing partners. Flat-rate shipping — same on 1, 2 or 3 packs. Built here. Breathe better.