Mark Lloyd wrote:

On Wed, 18 Jan 2006 18:30:48 GMT, CJT wrote:


Mark Lloyd wrote:


On Tue, 17 Jan 2006 23:49:34 GMT, CJT wrote:


snip

A programmable thermostat can help, and not only because it can be used
to set back temperatures during part of the day -- some (many?) of them
also have sufficient "smarts" to keep the system from short-cycling,
which is wasteful and potentially harmful to your system.



I know that's a problem for compressors. How would it effect gas or
electric heat?

I had AC in mind. I doubt it would help with heat, although starting
and stopping the furnace fan probably uses a fair amount of electricity.



How about an electric igniter? My furnace uses one of those. It's easy
to tell when you know what high-voltage wiring looks like (like the
spark plug wires in a car).


snip

I think it would be very interesting to know all the things folks
like Honeywell considered when they designed the algorithms for their
programmable thermostats. I suspect there's a lot more technology in
there than the instruction manual reveals.

Whether electric igniters have their own issues is beyond my expertise.

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