Hello. As suggested we have done a heat loss calculation--as a whole house and room by room. We have a heat loss of 35,000 btuh and presently have an 80,000 btu Bord-Warner furnace that is about 23 years old. We have received 4 estimates on 3 different brands. None of the estimators offered to run a heat loss calc and based their estimates on the size of the house and present furnace. One recommended a 60,000 btu, 2 stage, variable speed blower furnace based on the fact that it would run more efficiently than the existing furnace and, therefore, could be sized smaller. Two recommended an 80,000 btu, 2 stage furnace and said that the furnace would run at the first stage most of the time. A Rheem dealer recommended a modulating furnace with a 75,000 btu maximum output. From what we have read on this forum, it doesn't seem that we need an 80,000 btu furnace, but we are confused and would appreciate your input. We are looking at a Trane XV 90, American Standard Freedom 90, and a Rheem 75,000 btu modulating furnace. What size furance should we be looking at? Which is the better and most reliable brand? Should we be looking at a 90% furnace with fewer bells and whistles? We do have vaulted ceilings in two of the rooms so we are often cold before the heat kicks back on. Thanks for any insight you can give.