On Sun, 25 Jan 2009 19:30:24 -0800 (PST), Eric in North TX
wrote:

On Jan 25, 7:53*pm, dpb wrote:
KLS wrote:
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?

* 2(+/-) F/hr unless _WAY_ oversized would be pretty typical....you're
about right sounds like.

--

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.

The length of time the temp was low makes a difference. The thermal
mass of the structure and contents make a diference that becomes
greater if it has all chilled to match the lower temps. That stuff
takes a long time to heat back up.