From: mguyott@eriador.prime.com (M. Guyott)
Subject: Re: How to cut back my heat bill?
Organization: /etc/organization
Distribution: na
Date: Fri, 20 Nov 1992 22:48:50 GMT

In article <1992Nov20.183754.25322@porthos.cc.bellcore.com> mpb@troy.cc.bellcore.com (bunz,marcus p) writes:
>
>As with everything, there are exceptions. ...
>...  The setback also saves energy
>by having fewer on-off cycles of the furnace, so there is less
>energy wasted in getting the furnace and distribution system up
>to temperature.

I just recently purchased a Honeywell Chronotherm III.  It can be run in
two modes.  One mode is the traditional setback thermostat where you set
the time and the temperature.  At the given time the furnace will be turned
on and will remain on until the desired temperature is reached.  So the
temperature you set is reached at some point in time after the time you set.
The other mode is what they call their new "automatic" mode.  You set a time
and a temperature and the the thermostat figures out when to turn on your
furnace in order to have the house at the temperature that you specified AND
at the time you specified.  So instead of the furnace coming on at 6:30PM
the furnace will come on sufficiently early so that your house is actually
at the set temperature at 6:30PM.  This is nice because you can be specific
about when you want the house at what temperature.  The thermostat is supposed
to "learn" how long it takes to heat your house in about five days.  After
that the thermostat is supposed to know how early it has to start things up
to raise the temperature to the desired level.

My one concern is that the manual says that the thermostat will raise the
temperature in "steps".  i.e. run the furnace for a while then shut it off
and let the heat in the system absorb into the house (I have forced hot water
via natural gaas).  Supposedly, increasing the temperature in steps like this
conserves on fuel usage.  This is what the manual says.  But it does not make
sense to me because the furnace has to keep getting itself up to temperature.

It seems to me that my furnace is working a lot harder and I find it hard to
believe that I am actually saving energy (natural gas).  Am I losing more
for repairs and maintenance on my furnace because of the extra on/off cycles
to raise the temperature via these "steps" then I am saving in energy?  Am
I really saving any energy?  Anyone have any ideas?

I am currently using the thermostat in automatic mode.  I wish I could think
of some way to run it in each mode for a while and compare the results but
the weather here in NE is not very consistent so it is hard to compare day to
day or month to month gas usage (because of the temperature variations).

Marc
----
Two of the worst things we teach our children are that a knowledge of science
is nice but not necessary, and a knowledge of sex is necessary but not nice.

Marc Guyott              Constellation Software, Inc.          (508) 620-2800
                         Framingham, Mass. 01701 USA                Ext. 3135
mguyott@primerd.prime.com       ...!{uunet, decwrl}!primerd.prime.com!mguyott
mguyott@eriador.prime.com       ...!{uunet, decwrl}!eriador.prime.com!mguyott