If you have a 60K BTU or a 120K BTU furnace of the same efficiency, they will both use close to the same amount of gas per 1000 BTU load, the larger one will just heat up the house quicker. Just keep that in mind. [/B][/QUOTE]Originally posted by tostaos
If it helps I installed a Ruud, (Rheem), 60K BTU mod furnace in my home this fall. My old furnace was an oversised 80K BTU York 92% that was running fine. My gas usage is 40% less than it was a year ago! No other changes in life style to credit the savings to. With my old furnace I ran the blower anbout 6 hours a day, the Ruud hac been running 24/7 since the install. My electric usage has jumped so I think the blower will be set back to the old running times.
Thats only true if you have the duct work to handle the air that the 120 would need.