20x20x4
Found 20x20x4 on your old filter?
You're in the right place. You don't have to buy the same brand as before. What has to match is the thickness.
Measure how thick your old filter is.
Every filter below shows its brand under the picture, and the brand tells you the thickness.
3 3/4 inches → Camfil and AAF Flanders
4 3/8 inches → Five Seasons and Honeywell
No ruler? If your filter frame is printed FC100A1011, FC200E1011, X0585, MFH-2020-4 or AMP-11-2020-4H, it's the 4 3/8 inch one.
20x20x4 comes in two thicknesses
20x20x4 is the size printed on the filter. It is not the exact size.
The common one (our Camfil and AAF Flanders filters)
About 19 3/8 x 19 3/8 x 3 3/4 inches
The deeper one (our Five Seasons and Honeywell filters)
About 19 7/8 x 19 3/4 x 4 3/8 inches. Some retailers call it a 20x20x5.
Part numbers FC100A1011, FC200E1011, X0585, MFH-2020-4 and AMP-11-2020-4H are all 4 3/8 inches. They are printed on the filter itself, not on the box.
If your filter is 3 3/4 inches thick
Six filters fit, the ones marked Camfil and AAF Flanders. They all measure about 19 3/8 x 19 3/8 x 3 3/4 inches, so any of them replaces what you took out.
What matters most to you?
FILTRATION LEVEL
MERV 8 · Camfil AP-3: everyday household dust and pollen.
MERV 11 · Camfil AP-11: a step up for dust, pollen, pet dander and finer airborne particles.
MERV 13 · Camfil AP-13 or AAF Flanders: finer airborne particles, including tiny allergens.
A FILTER THAT LASTS LONGER
MERV 8 · Camfil 30/30: the same filtration as the AP-3, built to last longer.
MERV 9 · Camfil Dual 9: the longest lasting of the six, and a step up from MERV 8.
If your filter is 4 3/8 inches thick
Three filters fit, the ones marked Five Seasons and Honeywell. They all measure about 19 7/8 x 19 3/4 x 4 3/8 inches and go in the same cabinet, whatever brand came out of it.
What matters most to you?
MADE IN CANADA
MERV 11 · Five Seasons MFH-2020-4: the same MERV 11 filtration and the same rated life as the Honeywell FC100A1011. Made in Canada. Three filters in the box instead of five: a smaller box, and a smaller order. Also identified as AMP-11-2020-4H.
THE HONEYWELL PART NUMBER
MERV 11 · Honeywell FC100A1011: the part number printed on your old Honeywell filter. Five filters per box.
HIGHER FILTRATION
MERV 13 · Honeywell FC200E1011: the MERV 13 version. It captures finer airborne particles than a MERV 11, and it fills up sooner. Five filters per box.
Not sure what MERV means? Read the short version
Wondering when to change it? Here's how to tell
Camfil filters are tested to recognized industry standards, including ASHRAE Standard 52.2, so their MERV ratings are backed by standardized testing.
Still not sure which one is yours? Send us the numbers printed on your old filter, or call (888) 315-0105, and we'll confirm the right one before you order.