How Quickly Can A Furnace Raise House Temp 20F?
Just had the blower motor replaced on our York furnace this morning. Outside temps were 20F today with some wind. The new motor was assigned the task of warming the house from 45F to 65F. This took it 7 hours, which seems like a long time. How many degrees per hour is a usual rate of temperature rise for gas forced-air furnace?
Answer:
You're joking, right? You expect somebody to give you a figure without knowing the size of your furnace or the size of house? Hint: a twenty million BTU furnace is going to warm a dollhouse a bit faster than a bic lighter will warm up the taj mahal. FWIW, I have my programmable thermostat set to let the house cool about 5 degrees during the day when I'm not here, and I think it takes about an hour to bring it back up to temp, so I would say 4-5 degrees per hour isn't unreasonable. Your experience seems to be in the ballpark, particularly given the cold outdoor temperature. As the other posters have pointed out, there are many variables involved -- furnace size, house size, insulation effectiveness, outdoor temperature, etc. I guess mine is way oversize, i can pick up easily 10 degrees per 1/2 hour. I have the unoccupied downstairs set to 55 over night, & brought up to 68 at 6:30 am. I've never seen it not make 68 by 7:00 even when it is in the 20s outside. Why would more blower speed lower this temp range? It seems to me that the faster the air, the cooler the air blowing across elements/heat exchanger will be, and the more heat is getting transferred in.