Everyone has heard (well, at least home owners) how installing a programmable thermostat will save you money. But the question is always “how much money will I save?”.
I’ve had a few debates with friends (engineers), trying to calculate how much these could save you and what are the optimal temperatures to set. We’ve talked about the rate at which heat escapes a house vs. the fuel required to maintain that temp, about the break even point between cooling your house off to much during the day vs the fuel required to bring it back up to temp. All kinds of thermodynamic and heat mass transfer subjects that I thought I had left behind in the Mechanical Engineering building.
To date, my “scientific” method for determining the set point temperatures in my home has been to see what temp I’m comfortable at during the day (72*F in the winter) and what temp wakes me up in the middle of the night (60*F) and use those values. But something that I never looked at was how much this was actually saving me.
Well, with winter here, my natural hate for being cold set in and I decided one day to see if the chilly nights were really worth it. So I essentially turned off my programmable thermostat, locking it at 72*F for a month. The goal was to compare my gas bill to the previous month and see how much I’m saving.
Now, this experiement was far from scientific as I have no way to control or account for parameters like month-to-month differences in daily temperature, wind speed, hours and angle of sunlight, etc, etc. But, I think the results gave me the answer I was looking for nonetheless.
My gas bill came today and in the month where I locked the thermostat at a set temperature, my gas bill more than doubled! I was really surprised by this. I expected a difference of maybe $20-$40/month, but instead it jumped $70 from the previous to the current month. So, as soon as I saw the bill I walked over to the thermostat and placed it back on its regularly scheduled program. Maybe I’m a little cheap, but $70/mo is enough for me to pull the blankets up just a little tighter at night.
Your monthly delta will be different depending on what kind of heat you have in your house (I have forced air fueled by LP), your rates, the insulation in your house, your climate, etc. But, the result of this little “experiment” was enough to make me a believer. So, as soon as you’re done reading this, go out and buy a programmable thermostat and you too can trade cold toes for some monthly savings.
