I am going to have a new furnace and all new duct work put in my house to replace the 35 year-old system I have. So far, I've had 3 HVAC guys come out to give an estimate. One took down info for a load calculation, and the other two did not. They just looked around. Is it common for HVAC estimators to skip the load calculation for small houses? I would think that, after a while, these guys have enough experience to more or less know what a house will need, but maybe I'm wrong.
I haven't received the estimate from the guy who took all the load calc info. The other two guys recommended the following:
Carrier 58MTB (96% efficient, two-stage, 38,000 - 128,000 BTUh) with alumaflex ducts
Bryant 3350AAV (96% efficient, two-stage, 40,000 - 138,000 BTUh) with wireflex ducts
But, I decided that I'm not going to have the wire flex installed b/c it is going in the crawlspace under the house.
My house is a 1,450 sq. ft. Craftsman Bungalow from 1922. There is insulation in the attic, but not under the floor. I don't know if the walls are insulated. There are 21 windows in the house, and 18 are double paned. The tempurature rarely gets below 45 degrees where I live. Does the Carrier with 38,000 - 128,000 BTUh sound about right?