It's frikkin cold outside

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LeoC2

New member
OK, set backs and programmable and learning thermostats. Everyone from the users to the energy suppliers say that using a set back thermostat saves money. Here's the thing though... Can someone show me proof? I have for years wondered why and how we are saving money by this practice.

I have simple questions:
- Setting the thermostat to 70 or set to 65... does it take more energy to MAINTAIN 70 than it does 65? In other words does it take more energy to MAINTAIN a high temperature (70) as opposed to a low temperature(65)? Seems to me it shouldn't make any difference.
- Setting the thermostat down several degrees at night then having to raise the heat in the morning. Does it use less to maintain the lower setting and bring it back up? Or does it actually use more fuel to bring the temperature up to comfort? Never mind the comfort factor at night, I'm just talking fuel or gas use here.
- If going away for a few days does it save to reduce the temp to say 50 or leave it at 68? If it costs no more to maintain temperatures then why bother and have to come home to a cold house with a chill that will take a few hours to heat up?
 
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steve

With "LOD" Since 1997
I thought you people used coal to heat your homes. :p

So no wind and 18 deg, it is all relative, it feels balmy out, went out with no hat or gloves and was fine now, I am like a Sherpa acclimated to the Himalayas ;)
 
driller

driller

El Presidente
LeoC2 said:
OK, set backs and programmable and learning thermostats. Everyone from the users to the energy suppliers say that using a set back thermostat saves money. Here's the thing though... Can someone show me proof? I have for years wondered why and how we are saving money by this practice.

I have simple questions:
- Setting the thermostat to 70 or set to 65... does it take more energy to MAINTAIN 70 than it does 65? In other words does it take more energy to MAINTAIN a high temperature (70) as opposed to a low temperature(65)? Seems to me it shouldn't make any difference.
- Setting the thermostat down several degrees at night then having to raise the heat in the morning. Does it use less to maintain the lower setting and bring it back up? Or does it actually use more fuel to bring the temperature up to comfort? Never mind the comfort factor at night, I'm just talking fuel or gas use here.
- If going away for a few days does it save to reduce the temp to say 50 or leave it at 68? If it costs no more to maintain temperatures then why bother and have to come home to a cold house with a chill that will take a few hours to heat up?
Click to expand...
Proof is all in calculating heat loss/gain.

Setback programs can save money but perhaps not as much as some would have you believe. It is all derived from the heat loss of any particular enclosure and the heat capacity of the contents and envelope. In any typical enclosure, heat loss (or gain) is greater with temperature differential. So technically, it takes more BTUs to maintain a higher internal temperature at any given external temperature just as it does to maintain a fixed inside temperature with a colder outside temperature. It is also true that it takes more BTU input to raise the internal temperature than it does to maintain a temperature. The trick is to find the balance point where the saved BTUs from setting back the thermostat exceed the expended BTUs from returning to the desired temperature. It is obviously complicated further since the external temperature is a moving target.

So, to answer your first question, yes it takes more energy to maintain 70 than it does to maintain 65 since the heat loss is higher at 70 all other things being equal.

The second question is a time equilibrium balance problem. You will use less BTUs to maintain a lower temperature setting, but the time at the lower setting determines the total BTUs saved while the temperature difference determines the BTUs required to raise the temperature back to the original setting. This is a wildly variable situation and the answer depends on many factors, but length of time and the temperature 'setback' in degrees are the predominant variables.

The 'away' question is simply an exaggerated version of the nightly setback. But almost always the answer is it saves money to cut the thermostat back when you are 'away'.

The usual answer is the 'programmable thermostat' but few are actually programmed to maximize efficiency while retaining comfort especially considering the optimum setback temperature is constantly changing. Hence the promise of a 'learning thermostat' like the Nest. Not only will it operate as a programmable thermostat, it 'learns' from the user input and the connectivity since it 'knows' the external temperature and the temperature forecast.
 
driller

driller

El Presidente
steve said:
I thought you people used coal to heat your homes. :p
Click to expand...
We still do. :)

Except now we ship coal to the power plants and they provide electricity. 96% to 98% of WV electricity is generated by coal and WV typically generates more electricity than it consumes.
 
Green Machine

Green Machine

New member
Presently here in the Twin cities, Mn, it is 5 deg. tomorrow, ahem, will have a high of -10 deg with a low of -21. wind chills could be well below -60 below zero...... just another day in paradise....it makes working on your Mark Viii kinda interesting.
 
Roadboss

Roadboss

On Work Release
I was blessed with having to replace my 2 furnaces (dual zone) last winter due to their age. The replacements are the new Carrier units and they have a brain in them that controls both the combustion rate, and also the blower speeds ( variable speed blower). When I built this house (25 yrs ago) I had it built with 2" X 6" outside walls and had it well insulated all around. That said I have seen savings with these new furnaces. I have experimented over time and have come to the conclusion that I am better off setting the thermostats at one temperature and leaving them set. I have them set at 70 degrees during the winter.
 
S

steve

With "LOD" Since 1997
man that is cold, don't know why people would not move south. they say we are having MN like weather here back east, it sucks.
 
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Lownslowlsc

New member
Getting down to -21 here tonight, no idea about the wind chill. -2 now and don't think it's supposed to break zero today.

This is one winter I'd love to forget.
 
Slowmkviii

Slowmkviii

i want summer
Its getting warmer here, up to -17°f what really sucks is that with this cold its windy too and for me that means snow blowing my drive way every other day cause of 1-2 foot drifts blocking me in.
 
budpytko

budpytko

Super Senior Associate
50* here now.... will be 5* at 8AM tomorrow! And I moved her to get AWAY from upstate NY winter!
 
tixer

tixer

Lincoln Evangelist
-17 was "warm enough" to go out to breakfast with a couple friends. (School is canceled today, so no work for me.) I discovered this nice little Finnish cafe in St. Paul, and had some oatmeal and cardomom pancakes. :)
 
tixer

tixer

Lincoln Evangelist
http://finnishbistro.com/food/

"Finnish Oatcakes" - Ground old fashioned oats blended with fresh buttermilk and cardamom grilled until golden brown served with cinnamon spice butter and Sugar Bush maple syrup.
They were pretty fantastic.

Next time, I'm trying the "Potato Lefse Scramble" though. Their "French" toast is pretty incredible too..
 
mlschultz

mlschultz

Boost King
The Governor just announced a state of emergency for Georgia.

I am hunkered down in the house.

The hill I live on has turned to ice. Nobody driving up or down the hill

65* is the forecast for this weekend. Hope I can make it until then.







 
redn8

redn8

LOD Officer
Same here Mike. The high today was 20 and and snow all day.The interstates are closed. Many people have abandoned their cars and are walking home and many more are stranded at work. It's a real mess, we aren't set up to handle this kind of weather.
 
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mlschultz

mlschultz

Boost King
lol Norm, It's pathetic here. I shoveled my sidewalk with the leaf blower. Total snowfall about 2" by me. The snow does pack down and become ice very easily. People are abandoning their cars and walking around here too. Some schools did not let the kids out early enough, and they are stuck spending the night at school. What a nightmare.
 
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