PadMatch / Every humidifier water panel and furnace filter size
- Nominal size
- 20 x 25 x 5 in
- Actual size
- 19.875 x 24.875 x 4.375 in
- Depth class
- 5 in (media cabinet)
- Typically installed on
- five-inch media cabinets, most commonly Lennox Healthy Climate (X6675) and compatible cabinets
- Sold in MERV
- sold in MERV 10, 11, 13 and 16 as pleated media
Nominal versus actual dimensions for the 20 x 25 x 5 in furnace and HVAC air filter.
A 20 x 25 x 5 in furnace filter has an actual size of 19.875 x 24.875 x 4.375 in. The label is the nominal size, rounded up so the filter is easy to name; the panel is cut undersize so it slides into the slot without binding.
A five-inch nominal media filter that actually measures about 19.875 by 24.875 by 4.375 inches. The five-inch label describes a filter that is really four and three-eighths inches deep, which is why a true four-inch filter rattles in a five-inch cabinet.
Order by the nominal size printed on the old filter frame, not by measuring the slot, because every brand runs to the same nominal-to-actual convention.
Find your model
Read the number stamped on the humidifier cabinet or printed on the old pad, then match it below. Confirm the frame size before buying a generic.
- 20 x 25 x 5 in actual sizenominal vs actual dimensions
- 16 x 25 x 5 in furnace filteractual 15.75 x 24.75 x 4.375 in
- Lennox X6675 media filterLennox X6675
- MERV 8 vs 11 vs 13 for a furnace filterwhich rating to buy
Sources: Atomic Filters nominal vs actual air filter size chart ยท Lennox X6675 20x25x5 media filter actual size (Atomic Filters)