I have an 1100 sq ft home with a crawl space and 9 ft ceilings that was built in 1905. The previous owner put in an electric furnace in the attic that is too small to heat the house. The ducts are in the ceiling, I've been using a pellet stove to heat most of the house, but also have to run electric heaters in one bedroom, the laundry room, and bathroom. I don't know if it would be cheaper in the long run to have a bigger furnace installed in the attic. I was told they would have to convert over to a newer style furnace/ac system.