What Size Air Filter Does a Carrier 59SC5 Take?
Last verified July 2026
The Carrier 59SC5 takes a 16x25x1 air filter (actual size 15.5 x 24.5 x 0.75 inches).
Verified against Carrier manual 59SC5-04SI, page 14.
| Nominal size (order this) | 16x25x1 |
|---|---|
| Actual size | 15.5 x 24.5 x 0.75 in |
| Recommended MERV | 8-13 |
| Replace every | 90 days |
| Unit type | furnace |
| Source document | Manual 59SC5-04SI, p.14 |
How to confirm your exact size in 60 seconds
- Read the old filter. The nominal size is printed on the cardboard edge, e.g.
16x25x1. If it is legible, that is your answer and you are done. - Find the filter slot. On the Carrier 59SC5 the filter sits in the return air path — either a slot beside the blower compartment or a return grille in a wall or ceiling.
- Measure if unreadable. Measure length × width × depth with a tape, then round each figure up to the nearest whole inch. That rounded figure is your nominal size.
Worth knowing: Some installs use a 20x25x1 external filter rack instead. Check the rack, not the cabinet.
Filters that fit a Carrier 59SC5
Any 16x25x1 pleated filter in the MERV 8-13 range fits this unit. Typical US retail pricing at the time of writing:
| Filter type | MERV | Typical price | Best for |
|---|---|---|---|
| Basic pleated | 8 | $4 – $8 | Standard homes, no allergies |
| Allergen pleated | 11 | $8 – $14 | Pets or mild allergies |
| High-efficiency | 13 | $14 – $22 | Allergies — check airflow first |
| Washable | 4 – 6 | $20 – $35 once | Low filtration, less waste |
Price ranges are indicative US retail figures and change over time. We do not sell filters and earn nothing from these figures.
Three mistakes that waste money
- Ordering by actual size. Ordering "15.5 x 24.5 x 0.75" instead of "16x25x1" gets you a filter an inch too small, and air bypasses the media entirely around the gap.
- Jumping straight to MERV 16. A denser filter on a system not designed for it raises static pressure, cuts airflow and can freeze the coil. Stay inside MERV 8-13.
- Installing the arrow backwards. The airflow arrow must point toward the blower, away from the return duct. A backwards filter collapses under pressure and sheds fibres.
Same filter size, other Carrier models
These Carrier units take the same 16x25x1 filter in a standard factory installation: Carrier 59SC2. Confirm against your own filter before ordering, since retrofitted racks change the size.
Frequently asked questions
What size filter does a Carrier 59SC5 use?
The Carrier 59SC5 uses a 16x25x1 nominal filter, which measures 15.5 x 24.5 x 0.75 inches actual. This is confirmed in Carrier manual 59SC5-04SI, page 14.
What MERV rating is recommended for the Carrier 59SC5?
MERV 8-13 is the recommended range. Going above MERV 13 on a residential furnace can restrict airflow and reduce efficiency unless the system was specifically designed for a denser filter.
How often should the filter be changed on a Carrier 59SC5?
Every 90 days for a standard 1-inch pleated filter. Homes with pets, smokers, or ongoing construction should inspect monthly and change sooner when the media looks grey.
Why is the actual filter size smaller than the nominal size?
Nominal size is a rounded label used for ordering. Actual size is the true measurement, usually about half an inch smaller, so the filter slides into the slot without binding. Always order by the nominal size.
Can I use a thicker filter in a Carrier 59SC5?
Only if the cabinet or filter rack physically accepts it. A 1-inch slot will not take a 4-inch media filter without an adapter cabinet. Fitting a thicker filter where it does not belong leaves gaps that let unfiltered air bypass the media entirely.