On Tue, 22 Jan 2013 18:15:08 -0800 (PST),
wrote:




I'm pretty sure the supply ran in the basement and was probably added after the two halves were assembled. With the furnace on it got warm and if it was insulated I'm not sure the basement would freeze here in Pa, just seemed like wasted money. The owner was a older women who for 5 years had no problems but only now in her sixth season complained of cold, almost seemed like she was complaining of air currents. All the windows were "closed" but some were not latched properly. She had had several heat contractors out to try and solve her problem. One installed a new larger central duct(uninsulated) in the basement but that did not seem to solve her problems, that did not make sense to me as the house worked fine in its original configuration. I'm pretty sure that the house acts as the return to the furnace. The homeowner said she cleaned the filter regularly. I guess its time for another heating contractor.

I will advise the home owner, thank you for your help!

Given that it was OK for a few years, it is not the duct. What
changed? I'd check that she did not close or open some vents, that a
duct did not come apart inside a wall, that the blower switches are
going on and off at the proper temperature, that the blower is running
properly, temperature limit switches are working properly, and that
sort of thing.

Oh, don't for get the chimney or vent for obstructions. Bird's next
or dead squirrel can make a difference. Did she lose her cat?