Carrier 58MCB120-20 furnace filter size
This furnace takes a 16 x 25 x 1 (3/4 in. actual) filter (side (upflow only) return) or a 24 x 25 x 1 (3/4 in. actual) filter (bottom return), depending on where the return air comes in.
Every filter option for this model
| Where return air enters | Filter size (inches) | How many |
|---|---|---|
| side (upflow only) | 16 x 25 x 1 (3/4 in. actual) | 1 |
| bottom | 24 x 25 x 1 (3/4 in. actual) | 1 |
Where the filter goes
Inside furnace blower compartment (or external filter/media cabinet). PD p4-5: 'Filter Size --- In. (mm) ---Sold Separately'. SI: 'Table 4 indicates filter size and location for this furnace.'
The maker does not ship a filter with this furnace. The size above is the maker's recommended size at the furnace; if your home has a filter grille in a wall or ceiling, that grille sets the size instead.
How often to change it
General guidance, not from the maker's table: 1-inch filters every 1 to 3 months; 4- and 5-inch filters every 6 to 12 months. Change sooner with pets, smoking or construction dust.
About this model
| Cabinet width | 24.5 in. |
|---|---|
| Airflow direction | 4-way multipoise (upflow/downflow/horizontal), condensing |
| Heat input | 120,000 BTU/hr |
| Model number note | Docs list unit size as 040---08 etc.; nameplate adds series characters (Series 110/120). |
How to read a Carrier model number
Source
- Carrier 58MCB-4SI Installation, Start-up, Operating and Service and Maintenance Instructions (installation manual, page 25): document. Read 2026-11-03.
- 58MCB Product Data (58MCB-6PD), Specifications table (product data / spec sheet, page 4-5): document. Read 2026-11-03.
Check that the model number on your furnace label matches, and compare with the size printed on your old filter. If they differ, go by the filter that fits your rack.