Allied Furnace: Upflow 5-ton units with 1800 cfm or more airflow
Upflow 5-ton units with 1800 cfm or more airflow on a Allied furnace: Upflow 20C and 20D (5 ton) units that need 1800 cfm or more have to be set up with one of the listed return air arrangements. Too little return opening means high velocity, noise and a poor temperature rise.
Applies to: 20C and 20D (5 ton) size units, upflow installations
Common causes of upflow 5-ton units with 1800 cfm or more airflow
- Single undersized return for a 5 ton airflow
- Filter or transition too small for the cfm needed
- Return arrangement not on the approved list for 1800 cfm or more
How to fix upflow 5-ton units with 1800 cfm or more airflow: step by step
- Use single side return with a transition sized for a 20 x 25 x 1 in. cleanable filter.
- Or use single side return with the optional RAB Return Air Base.
- Or use bottom return air.
- Or use return air from both sides.
- Or use bottom and one side return air.
- Check the blower performance tables for the airflow limits before you commit to an arrangement.
If the unit shows an error code, look it up: Allied Furnace codes
Models
92G1UH92G1UH0450892G1UH0451292G1UH0700892G1UH0701292G1UH0901292G1UH0901692G1UH1101692G1UH1102092G1UH1352095G1UHA93UHA95UH
Source: Allied 92G1UH installation manual, p. 6. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.