furnacefiltersize.com

Aprilaire filter cabinet models (210, 213, 410, 413).

Aprilaire 213 is sold as 20×25×4. Aprilaire’s own shop lists the actual size as 20.6 × 26.63 × 4. A Filterbuy 20x25x4 is 19.5 × 24.5 × 3.63. Those are not substitutes.

213 — official shop (retrieved 31 Aug 2026)

Source: shop.aprilaire.com/products/aprilaire-213-replacement-filter.

Fits air cleaner models 1210, 1620, 2210, 2216, 3210, 4200. With upgrade kit 1213, also 2120 / 2200 / Space-Gard 2200.
MERV 13. Replacement 12 months.
Nominal 20 × 25 × 4. Actual 20.6 × 26.63 × 4. Actual is larger than nominal (Self-Seal). This is the opposite of a 1-inch pleat.

Home Depot listing for 213 H1 also names models 1210/1620/2210/2216/3210/4200.

Do not order “20x25x4” from Filterbuy or Amazon and expect it to seal in a 2210. If the finder just gave you 20x25x4 and you have an Aprilaire cabinet, stop.

Photo needed: Aprilaire 2210 cabinet sticker next to a 213 cartridge label.

Photo needed. Self-Seal gasket is the reason actual > nominal.

Cabinet model → filter SKU

20x25 cabinets take 210 (MERV 11) / 213 (MERV 13) / 216 (MERV 16) / 213CBN (carbon). 16x25 cabinets take 410 / 413 / 416. Do not put a 213 in a 1410/2410 cabinet. 213 actuals from the shop page; 410/413 actuals need the spec PDF — not invented here.
Cabinet	MERV 11	MERV 13	MERV 16	Nominal	213 actual (shop)
1210, 1620, 2210, 2216, 3210, 4200	210	213	216	20×25×4	20.6 × 26.63 × 4
1410, 2410, 2416	410	413	416	16×25×4	not published here until the spec PDF is filed

210 vs 213

MERV 11 vs 13 in the same deep cabinet. This is the safe MERV 13 path the 1-inch page points to. Depth is already media; static drop is not the 1-inch problem.

Honeywell FC100 vs Aprilaire 213

Honeywell FC100A1037 is sold as a 20x25x4/5 media for F100/F200 and is also listed as compatible with Aprilaire/Space-Gard 2200 in some merchant copy (FiltersFast: nominal 20x25x4, actual 19.94 × 24.86 × 4.38, 0.23 in. w.c. at 500 FPM, MERV 11). That actual is not the Aprilaire 213 actual. Cross-compatibility claims need the IOM, not a merchant “fits 2200” line.

Until we have the Honeywell IOM in the repo: Space-Gard 2200 owners should confirm whether they are on OEM Aprilaire media (213 family, actual ~20.6 × 26.63) or a Honeywell F100-style cartridge before ordering.

Affiliate: FiltersFast Aprilaire and OEM Aprilaire via Amazon as backup. Filterbuy 20x25x4 only with a hard “not a 213 substitute” label.

Cabinet hub · Carrier · 12-month 213 cadence · 1-inch MERV 13 (draft).