how to determine OLG furnace efficiency rating

[lyall coburn]

Does anyone know how to find out the efficiency of an UCL furnace model OLG 105/122 ser # 950/100/108 ???

[Jim Katen]

Does anyone know how to find out the efficiency of an UCL furnace model OLG 105/122 ser # 950/100/108 ???

On the data plate, compare the input BTU/hr rating to the output BTU/hr rating.

- Jim in Oregon

[Mark P]

Hi Jim,

That sure is interesting and I'm surprised I had not leaned that earlier in my life.

I was looking at an old furnace the other day (1976), and I was just assuming, based on its age, and the huge flame it produced, it was very inefficient. On the data plate there was the following info:

INPUT: 125,000 BTU/HR

BONNET CAPACITY: 100,000 BTU / HR

MINIMUM INPUT: 87,000 BTU / HR

So since 100,000 is 80% of 125,000 then the unit is in fact 80 afue, is that how it works?

[Bain]

Does anyone know how to find out the efficiency of an UCL furnace model OLG 105/122 ser # 950/100/108 ???

On the data plate, compare the input BTU/hr rating to the output BTU/hr rating.

- Jim in Oregon

This is also a useful method to make certain some lunkhead didn't connect a PVC flue-pipe to an 80% furnace.