Programmable Thermostats = bad?

[spearchucker]

I knew that mine was on it way out and wanted to replace it on my terms when I could get a good deal, not in the middle of January when it is below 0. Then you just bend over.

I went from a mid 70's model that was about 65-70% efficient to a 95% model so it was a big jump. With the rebates and tax credit it was cheaper to buy top of the line equipment.

[swamptiger]

Quote:

Have I got this right?

Sounds right to me. I have a heated shop that I usually keep at about 65 degrees during the day, but I turn the thermostat down to about 45 degrees at night. Quite sure I'm saving some fuel.

This is a little off-topic, but one thing I found out when studying the newer condensing type boilers is that the efficiency of the boiler is affected to a large extent depending on the temperature differential of the heated water going out of the boiler vs the return water. The larger the Delta T, the better the condensing effect, and the greater the efficiency. Which is basically contrary to the way the old-style boilers were operated - I think the general recommendation was to never exceed a 20 degree differential, because it would be hard on the boiler.

If you think of the Delta T or temperature differential in terms of a pressure differential, and apply it to air temperature, in my mind the greater the difference, the more the cold air would be trying to replace the warm air.

[BoxMN]

I knew that mine was on it way out and wanted to replace it on my terms when I could get a good deal, not in the middle of January when it is below 0. Then you just bend over.

I went from a mid 70's model that was about 65-70% efficient to a 95% model so it was a big jump. With the rebates and tax credit it was cheaper to buy top of the line equipment.

Spearchucker, that is exactly what I did. The AC carped out in August about 5 years ago, so I just weathered the rest of the heat, and shopped around and ended up getting ac and furnace in Sept/Oct, and installed my old furnace in my detatched garage where it works great.

The prog. T-stat and 92.5% eff. furnace with DC variable speed motor has made the home more comfy and saved us money, even with the hgier cost of gas AND me heating the garage to 38 degrees all winter, my Excel bills are lower than 5 years ago.