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Carrier 59SU5B filter sizes: 14 x 25 x 3/4, 16 x 25 x 3/4, 20 x 25 x 3/4 and 24 x 25 x 3/4, as listed in the Carrier source document's filter table. Which size fits depends on your cabinet and return. This page is pending human review, so check the source excerpt below.
Auto-extracted · review pending Filter sizes auto-extracted from the manufacturer document.
Last checked against the manufacturer document:
| Sizes found in the source table |
|---|
| 14 x 25 x 3/4 |
| 16 x 25 x 3/4 |
| 20 x 25 x 3/4 |
| 24 x 25 x 3/4 |
Extracted by script from the linked document. Read the excerpt to see which size applies to which cabinet or return.
General guidance (not from this manual): check monthly and replace 1-in. filters every 1–3 months, or follow the filter maker's guidance and your owner's manual.
Pull the old filter and read the size printed on its frame. Nominal sizes are rounded up: a 15.5 x 24.5 in. filter is sold as 16 x 25.
Your furnace manual lists the filter's dimensions, not its MERV rating. Higher-MERV filters restrict more air. Manufacturers such as Carrier recommend keeping the clean-filter pressure drop under 0.2 in. w.c. (ideally under 0.1). Lennox warns that an over-restrictive filter can trip the high limit in winter and freeze the coil in summer. If you want MERV 11–13, a 4-in. media cabinet is the usual route. Ask an HVAC tech to check static pressure. Nominal sizes are rounded: a filter labeled 16 x 25 x 1 actually measures about 15.5 x 24.5 x 0.75.
Manufacturer document for Carrier 59SU5B
Last checked 2026-11-02. Manufacturers revise documents. If your unit's label disagrees, trust the label.
59SU5B: Installation, Start-up, Operating and Service Maintenance Instructions
Table 8 – Air Filter Selection and Duct Sizing - In. (mm)
FILTER SIZE
FURNACE CASING WIDTH FILTER TYPE*
SIDE RETURN BOTTOM RETURN
14-3/16 (360)† 16 x 25 x 3/4 (406 x 635 x 19) 14 x 25 x 3/4 (356 x 635 x 19) Washable
17-1/2 (445) 16 x 25 x 3/4 (406 x 635 x 19) 16 x 25 x 3/4 (406 x 635 x 19) Washable
21 (533) 16 x 25 x 3/4 (406 x 635 x 19) 20 x 25 x 3/4 (508 x 635 x 19) Washable
24-1/2 (622) 16 x 25 x 3/4 (406 x 635 x 19) 24 x 25 x 3/4 (610 x 635 x 19) Washable
*. Recommended to maintain air filter face velocity. See Product Data for part number.
†. Not all families have these models.
Table 9 – Opening Dimensions - In. (mm)
FURNACE PLENUM OPENING FLOOR OPENING
CASING WIDTH APPLICATION
A B C D
IN. (mm)
14–3/16 Upflow Applications on Combustible or Noncombustible Flooring 12-11/16 21-5/8 13-5/16 22-1/4
(360)* (subbase not required) (322) (549) (338) (565)
17–1/2 Upflow Applications on Combustible or Noncombustible Flooring 16 21-5/8 16-5/8 22-1/4
(445) (subbase not required) (406) (549) Carrier 59SU5B filter sizes: 14 x 25 x 3/4, 16 x 25 x 3/4, 20 x 25 x 3/4 and 24 x 25 x 3/4, as listed in the Carrier source document's filter table. Which size fits depends on your cabinet and return. This page is pending human review, so check the source excerpt below. 14 x 25 x 3/4; 16 x 25 x 3/4; 20 x 25 x 3/4; 24 x 25 x 3/4.
General guidance (not from this manual): check monthly and replace 1-in. filters every 1–3 months, or follow the filter maker's guidance and your owner's manual.
Filter sizes are nominal (rounded). A filter sold as 16 x 25 x 1 actually measures about 15.5 x 24.5 x 0.75 in. Buy by the nominal size printed on the frame.
Every size found in the source table is 3/4 in. thick: 14 x 25 x 3/4, 16 x 25 x 3/4, 20 x 25 x 3/4 and 24 x 25 x 3/4. Pending human review; check the excerpt.
Manufacturer document for Carrier 59SU5B (https://www.shareddocs.com/hvac/docs/1009/Public/0B/59SU5B-03SI.pdf), last checked 2026-11-02.