I'm in the process of shopping for a new Furnace and A/C. Some have done the Manual J, some have not. They have all come back with similar numbers. However I have a few questions.
1. One measured from the outside of the house. I thought the manual J needed to be done from the inside? He came back with similar numbers but I was just curious.
2. The trane dealer wants to put in a 2.5 ton condensor and a 3 ton coil. Shouldn't they match?
3. I have a general concern about the size of the furnace. The one being replaced is a 44 year old Lennox 100k BTU. It was rated as 54 AFUE. So does that mean I was getting 54000 btus of heat? If so most of the contractors want to put in either a 69k or 88k furnace and 90+ AFUE. The old furnace heated the house fairly well. Doesn't it seem like these new units would be oversized?
Thanks in advance for your advice.