Re: [GBlist] question about turning heat down

[Ron Cascio <rcascio@beachin.net>]

Corwyn wrote:

> On Monday, January 28, 2002, at 10:51 AM, Anja Kollmuss wrote:
>
> > I teach environmental classes and I run into this question again and
> > again:
> >
> > How much should one turn down the heat at night: It it true that it is
> > better not to lower the heat by more than 10 degrees (eg. to 58 from
> > 68), because it would take more energy to heat the rooms back up (say
> > fom 50 to 68)?
> >
> > Can someone explain this to me?
> > Thanks so much!
>
> Teaching a teacher; what fun!
>
> Simple version: A house loses a certain amount of heat every hour.  A
> furnace can replace that as it is lost, or the next morning.  Fuel use
> is the same.  Thus, turning down the heat can never use more energy.
> ........

   Hope This Helps.

> Corwyn

   Such may not be the case if the heating plant is a heat pump with an
electric resistance back up coupled with a standard thermostat that is not
set up to deal with asking for more heat than the outside compressor can
give at a given outside temperature in a short period of time. For instance,
the thermostat is set at 70* and I lower the temp to 55*. The outside temp
drops to, say 35* during the night and when I wake up at 6 a.m. I bump the
`stat back up to 70* while the inside temp is, say 60*. By asking the
compressor (with a standard thermostat) to move the temp up 10* the
resistance heat will kick in, surely negating any electric savings during
the evening by lowering the temp. If you were to bump the `stat up a few
degrees at a time, careful not to kick in the resistance heat, you will be
able to avoid the savings loss. There are thermostats availble that will do
this automatically also.


Ron


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