Ok here is the deal
I recently moved in a house build in 74. The furnace is gas and there is an outdoor condensor for AC. The AC has been upgraded including the replacement of the condensor coil, tubing and condensor itself. The furnace however, is original with the house it is an old Lennox G12D2-82-1. From reading on the unit it says Input:85,000 BTU/HR Bonnet Capacity 65,600 BTU/HR. My home is relatively small only 1,200 SQFT. I am a handyman and a do it yourselfer type of person. I notice it appears that the entire Lennox Cabient can be removed and another furnace can be installed with minor modification of the ducting so that it would mate. The furnace is configured for upflow. I have a couple of questions.
1. I was told that this furnace is probably a 65.8% AFUE and that I can go with a lower BTU furnace since the newer furnaces have a considerbly higher AFUE is this ture?
2. Why does it say input capacity 85,000 and bonnet 65,600. When I see furnaces selling which BTUs are they advertising. In other words is this a 65,600 BTU furnace?
3. I was told again that it wouldn't make any sense going to a 90% AFUE furnace because I won't be able to recoup any of the gains if I'm staying a short time in the house. A 80% would be good enough. The old Lennox that is here works great now.
4. Does this furnace cabient literly come out. It appears to be a couple of screws on the top for the exhaust and the intake duct on the side and it could literly come out (correct)?