Yes , I've been told that 3 1/2 tons to heat that area , which is really about 1100 sq ft , is alot. I have been told by people that they heat 2000 sq ft with 2 tons. Then when you start questioning them ,you find out that they also use a vent less heater ,and the forced air furness only runs at night. "And my gas bills are around $90.00 a month" they say. I never use any Natural gas , unless it gets real real cold for a long time . Then I will use the vent less in the basement. I think some people like to stretch the truth when it comes to how much it costs them to heat their homes . Any way , that is how much I use , and from what I've read on this forum , that is about average amount used for a whole heating season.