# Best thermostat span setting?



## house92

Does a thermostat's span setting have any affect on the amount of energy used?

My digital thermostat has a span setting of 1,2, or 3 degrees.  With the 1 degree setting, it doesn't run very long when it is on, but it turns on and off more often.  With the 3 degree span, it doesn't kick on as often, but it runs longer.  

For whatever reason, I just dislike to hear a unit cycling on and off all the time; it just gives me the impression it's using more energy, but it may have nothing to do with anything.

My house is older, and I'm sure the insulation is not up to par with a modern home, but again, that may not make a difference with the span setting.


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## house92

Just to make clear, I'm asking if one is going to make my bill higher, or in my case, use more propane, or does it all equal out?  One runs longer but kicks on less often, while the other runs shorter, but kicks on more often.


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## guyod

The bigger span will use less energy.  Probably not enough to notice on your heating bill.  
There is some wasted heat to heating up the furnace and ducts every time it comes on.  Also the house will be a few degrees colder some times  which will save money.


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## kok328

Guyod, not that I doubt your word but, do you have any reference to substantiate your reply?
I too have an offset/differential T-stat and often wondered the same as house92.


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## house92

kok328 said:


> Guyod, not that I doubt your word but, do you have any reference to substantiate your reply?
> I too have an offset/differential T-stat and often wondered the same as house92.



Good question.

It's ok with me if other people post answers as well.  Surely there are people here who know a little about thermostats.


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## kok328

I've heard that programmable t-stats actually will cost you more money by having to re-heat the home after being lowered during the 'away' periods.  All the walls, floors, ceilings and furniture in the home will have to be brought back to temp.  This is similar to setting your offset to a couple of degrees to prevent short cycling.  I hope the pros chime in or someone with time on their hands to search for supporting or contradicting information helps us out here.


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## house92

kok328 said:


> I've heard that programmable t-stats actually will cost you more money by having to re-heat the home after being lowered during the 'away' periods.  All the walls, floors, ceilings and furniture in the home will have to be brought back to temp.  This is similar to setting your offset to a couple of degrees to prevent short cycling.  I hope the pros chime in or someone with time on their hands to search for supporting or contradicting information helps us out here.



I used to hear that about costing more to re-heat or re-cool and that it is more efficient to set it and leave it, but from what I have read in the last few years, that is a theory that has been put to rest.  

I've noticed something this evening.  It was in the upper 50s when i came home this evening and my heat had been off today.  It was 67 degrees in the house.  It has rained all day and there was a chill in the air, so I decided to turn the heat on to get rid of the chill.  I have it on 70 at a 3 degree span.  

I turned it on, it ran for a few minutes and heated to a low 72.  It's been over an hour, and the temp is at 70 and the unit has not yet come back on; however, if it were on the 1 degree span, it would have cycled a few times.

So, I guess there are times when the longer span is better.


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## nealtw

http://www.nspower.ca/en/home/energysavings/energymyths.aspx


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## bud16415

The next generation of thermostats if we are even going to still call them that are already coming to the market. They have some artificial intelligence and learn from how you adjust them. The step after that they are being tied into the internet and will anticipate future weather. That&#8217;s where the biggest savings will come from. Our 1,2 or 3 degree differential will also look ahead at what is trending outside both thru sensors and weather predictions even time of day etc. they will know when you are home and away and when you should be arriving back. These systems also have the ability to correct for peaks and valleys in the power grid. 
Few reads. 
http://nest.com/

http://www.yorkblog.com/greenmesh/2013/01/15/review-of-the-nest-2nd-generation-thermostat-installed/

http://www.treehugger.com/clean-tec...ur-thermostat-based-on-weather-forecasts.html

Mixed reviews:
http://www.amazon.com/Nest-Learning-Thermostat-Generation-T100577/product-reviews/B006ML9J4O

 Honeywell&#8217;s newest:
http://www.techhive.com/article/205...-thermostat-review-call-it-the-anti-nest.html


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## bud16415

Double post


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