On Oct 30, 4:31*pm, "Ed Huntress" wrote:


No, it's dead on, and based on a lot of actual experiments.

Don has explained
the problem correctly.

But he explained the wrong problem. He explained a theoretical
thermodynamics problem. The question is whether the savings would be worth
it if you only shut off the furnace for a relatively short time. And the
answer is, unless you live in a lightly-built and underinsulated trailer,
probably not.

Thermal mass and insulation determine the
thermal time constant, *which affects how much saving results. *But
has no effect on whether there is a savings.

Again, you're talking about a vacuum-bottle experiment. The question is
whether the savings are worth coming back to a 50 deg house.


Ed Huntress

You need to improve your reading comprehension. The question was

"Is it energy saving to turn the thermostat down, when
leaving the house?"

It was not whether the savings were worthwhile. Or whether a 50
degree house is comfortable. Incidentally the problem can not be
accurately described by lump constants. The electrical analogy is a
transmission line, not a capacitor.

Dan