Brands › Trane › XB90 (TUC1)
Trane TUC1B080A9421A furnace filter size
This furnace takes a 17 x 25 x 1 filter (not stated (spec table, upflow model) or upflow (bottom or side, in blower compartment) return).
Every filter option for this model
| Where return air enters | Filter size (inches) | How many |
|---|---|---|
| not stated (spec table, upflow model) | 17 x 25 x 1 | 1 |
| upflow (bottom or side, in blower compartment) | 17 x 25 x 1 | 1 |
Where the filter goes
Upflow: in blower compartment bottom or side on optional rack; "Filter and filter rack are not supplied with unit".
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 | 17.5 in. |
|---|---|
| Airflow direction | upflow/horizontal |
| Heat input | 80,000 BTU/hr |
| Efficiency (AFUE) | 92.1% |
| Model number note | trailing revision letter varies |
| Also sold as | American Standard AUC1B080A9421A |
How to read a Trane model number
Source
- Trane Product Data XB90 TUC1 Pub. 22-1669-15 (2017) (product data (spec sheet), page 5): document. Read 2026-11-03.
- Installer's Guide 18-CD19D5-35-EN (*UC1/*DC1, XB90) (2019) (installation manual, page 11): 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.