Programmable Thermostat - Energy Saving Question

[tefleming]

I'd noticed the "AUX" light on my thermostat coming on rather often lately, so I finally did a little research. Any time the actual temp - desired temp = first stage differential, the aux kicks in. (Same thing applies with EMER with stage two differential.)

First, can anyone confirm what I'm saying above as accurate?

Second, I just changed the differential amounts (don't remember the old values, but now they're at 3 / 5 degrees).

I use the programmable thermostat to drop the temp when I'm not here, but only have so many "windows" when I can change so I can't really have it gradually increase. (So now it's set between 67 not here and 70 here).

Has anyone else had similar issues? Am I messing something up by setting the differentials so high?

 

[tefleming]

nobody?

 

[Red Squirrel]

I don't have a programmable one but all I can say is be sure to not put it TOO low as it costs more to bring the house to a certain temp then to maintain it there. We usually just leave ours at 15-20. I usually put it at 20 when I see it at 15 though, since 15 is a little chilly for inside temp.

 

[tefleming]

I figured out more. I RTFM (after I found it online) and the "First Differential" is the degrees off desired at which the main unit kicks in.

I'm not sure what the second differential is.

Right now, I've got it on a 2deg 1st and 5deg second.

At-home temp = 70F
Asleep / Away temp = 66F

 

[Indolent]

Originally posted by: RedSquirrel
all I can say is be sure to not put it TOO low as it costs more to bring the house to a certain temp then to maintain it there.

That doesn't make any sense at all...


*edit* Further explanation...

Newton's law of cooling, states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings, or environment.

From an energy loss standpoint, you can never set it TOO low in the winter.

wiki

 

[Brainonska511]

EnergyStar guidelines for programmable thermostats: http://www.energystar.gov/inde...thermostats_guidelines