One sticker says Mueller installed 1973, however the furnace is clearly Bryant, so presumably it was installed after '73.
Next sticker says it removed the A/C filter in 1981 because it was leaking, and I know this to be true on the unit that's still there. So it was there in 1981, and presumably not new!
What do you think?
05:44PM | 06/25/17
Sorry folks - I didn't even think to look for a model or serial number but after some dusting I found them:
Serial # 07E138250
Perhaps I should be happy with "sometime between '73 and '81, but I'm particularly curious about its likely AFUE. Not good, I suppose. It is running just fine.
Thanks for your help in dating this thing.
06:10PM | 06/25/17
Now I'm pretty certain the 07E refers to the seventh week of 1976 according to a document I found online from The Inspector's Journal.
Perhaps this will help someone else.
Still interested in your thoughts on the efficiency.