"Ignoramus10802" wrote in message
...
On 2009-10-29, Pete C. wrote:

Ignoramus10802 wrote:

On 2009-10-29, Stormin Mormon
wrote:
Please forgive me while I troll for a moment.....

Is it energy saving to turn the thermostat down, when
leaving the house? I mean, the furnace has to run to catch
up when I get home. I have a way of looking at the matter.
I'll explain my point of view after the argument is
underway.


Imagine for a minute that you have to leave house for a month.

Would it be energy efficient to turn thermostat down? Of course, as
less heat will be produced for a whole month, with only a few minutes
to catch up.

The same applies to only one day.

i

It's far more complicated than that. Factors such as insulation / heat
loss, type of heating, multi-stage heating, electric backup heat on heat
pumps, etc. all come into play in determining the away duration and temp
reduction where savings begin, and in some cases (typically high
efficiency homes) it can require a multi day absence to see any savings.

This is patently untrue.

I

Correct - whatever the net effect of insulation is, there is a net negative
heat flux from the house to the outside. The flux is proportional to the
temperature difference (the exact equation will depend on the radiation,
convection and conduction components - radiation alone is governed by the
Stephan-Boltzman equation). The larger the difference the greater the flux.
Averaged over any period of time, any time spent with the thermostat set
lower will yeild a lower internal temperature, hence less heat flux.
Whether that is enough to show up in your bill is another question, but from
a energy savings point of view, it is incontestible.