Aprilaire 213 vs Honeywell FC100A1037: Which 4-Inch MERV 13 Wins?

The short answer

Get the Aprilaire 213 if your cabinet is Aprilaire. Get the Honeywell FC100A1037 if your cabinet is Honeywell F100 or F200. Both filter equivalently — the choice is about cabinet fit, not capture quality.

Side-by-side specs

• Aprilaire 213: 20x25x4 nominal, MERV 13, ~$50, 12-month, fits Aprilaire 2210/1210/4200, Space-Gard 2200
• Honeywell FC100A1037: 20x25x4 nominal (actual 19-7/8 x 24-3/4 x 4-1/4), MERV 13, ~$45, 12-month, fits Honeywell F100/F200, Lennox X6670 cabinet

Cabinet fit is the real decider

These two filters have slightly different actual dimensions despite both being labeled 20x25x4. The Aprilaire 213 measures closer to true 20x25; the Honeywell FC100A1037 is about 1/4 inch smaller in width. In an Aprilaire cabinet, the Honeywell fits with bypass gaps. In a Honeywell cabinet, the Aprilaire is too tight.

This is why OEM matters even when MERV ratings match: bypass air around the filter goes through your HVAC unfiltered.

What about capture performance?

Both are MERV 13 — meaning both capture 90%+ of particles 1-3 microns. In independent tests, the Aprilaire 213 has slightly higher initial efficiency on sub-micron particles, but the difference falls inside the ±2% MERV testing tolerance. Treat them as equivalent.

Pricing and replacement rhythm

The Aprilaire 213 runs $48-55 in 4-packs. The Honeywell FC100A1037 runs $42-48. Both are 12-month replacements at standard HVAC runtime. Cost per year is essentially identical.

Generic equivalents

Nordic Pure, FilterBuy, and Aerostar all sell 20x25x4 MERV 13 filters at 30-40% lower prices. They fit either cabinet because they're sized between the two OEMs. The tradeoff: slightly less consistent media quality, and the cabinet seal isn't as tight as OEM. If you change religiously, generics are fine. If your filter sits 11 months between changes, OEM wins.

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