02-16-12, 03:25 PM | #11 |
Master EcoRenovator
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wow, I don't ever turn my heat up to 72. I go up to 67 during the day and let it drop to 64 at night. The woodstove will get the house over 72 after running for a few hours though.
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04-02-13, 08:20 PM | #12 |
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The recent Ask This Old House episode had a realy good segment on the newest version of the Nest "learning" thermostat - skip to Chapter 5 (the fifth hash line on the bottom):
Video: Ask TOH | Painting Cabinets, Smart Thermostat | Watch This Old House Online | PBS Video They are pretty thorough in the walk-through of the features. |
04-03-13, 08:51 AM | #13 |
Steve Hull
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Tim,
Sadly, look at the degree day data with the dumb and smart thermostat. Yes, you paid 5% less with the smart one, but the heating load, as measured by degree days, was 11.5% lower in the interval when the smart one was in use. I support programable thermostats for the right application, but I not sure this data proves your point. Steve
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04-03-13, 10:13 AM | #14 |
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If you run the numbers, its actually a 16% decrease in natural gas usage. It a 5% decrease per heating degree day.
Programmable thermostats really are a never-loose kinda device. They pay for themselves very quickly in almost every case I've ever seen.
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04-03-13, 11:29 AM | #15 |
Steve Hull
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Daox,
You are right about the therm reduction (60.8 to 51.0 =-16.12). However the reduction of degree days is 1029 to 911 = -11.47. So , despite a decrease in the heating load of ~ 11.5%, there was a reduction in gas usage of 16%. Maybe that difference was where the 5% reduction came from . . . . Steve
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04-08-13, 01:09 PM | #16 | |
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Quote:
I compared natural gas use for the same billing period (Jan / Feb.) bill for the year before and after I installed the programmable thermostat. I then pulled the Heating Degree Day data (from wunderground.com) for the same days as the billing period for each year. Then I divided the Therms of Natural Gas used by Heating Degree Days (Therms / H.D.D.) to compare the difference the programmable thermostat made. Therms of Natural Gas used per Heating Degree Day was the point of comparison that showed the 5% reduction in Natural Gas used. There is probably a more accurate way to calculate the difference, but not with the tools that I have. I hope that helps, Tim
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