BTUs and blower motor
I'm replacing both the a/c and gas furnace due to a dead blower motor (system is 17.5 years old). Current furnace is 90,000 BTUs.
Two contractors are proposing 90,000 BTUs, one is proposing 100,000. The fourth is saying it should be 70,000 and that 90,000 is oversized for my home. House is 2280 sqft (not including basement). One contractor said that using the square footage, considering windows and insulation, about 108K was about right, but if I had been comfortable at 90K he would recommend leaving it there. (he acknowledged that his calculation was old-school and not perfect). It seems to me that 70K would be low. I'm in Maryland use the heat from sometime in October through April or early May.
One of the contractors thinks a variable speed furnace isn't good for my situation since I have bad air flow on the second story. His theory is that it would cycle on and off too much.
Any thought or suggestions are appreciated -- my head is swimming!