On Jun 29, 8:56*pm, MNRebecca wrote:
Concerning the electric thermostat that controls my Trane furnace and
air conditioner, if I change my fan switch from "Auto" to "On" (so
that it runs continuously), is it pulling in air from outside or just
circulating the air already in the house? *In other words, is running
the fan a good way to cool the house at night when the air temp.
outside is a good 15 degrees cooler than inside?

Thanks.

You already got the 'bad' news that it only circulates house air but..

The good news is that running it 'on' will significantly delay the
start of the AC. Much cheaper to run that fan than the AC. In my
case, when it becomes a bit uncomfortable in the house, putting it
"on" will keep the AC from running for another hour or two if it isn't
too hot outside.

Harry K