[Laurie Warner]

Laurie Warner  asked the Naked Scientists:
   
Dear Dr. Chris and crew,
 
I listen eagerly to both the "Naked Scientist" and "Ask the Naked Scientist" podcasts over here in the US.  

I am currently living in South Carolina, although I am from upstate New York originally.  (In case you're not familiar with the idiom, "upstate" New York is pretty much everything that's not New York City.  In South Carolina, it actually refers to the northern third or so of the state, in a slightly more logical fashion, and yes, I'm "upstate" here too.)
 
A couple of weeks ago, I think, you had a podcast which featured talk about climate, weather, and weather-related items.  

I was wondering whether you could address the following question:

When I lived in the Northeast, it was commonly accepted that one method of saving energy was to turn the thermostat down when you didn't need the house heated (or, occasionally in the summer, cooled) to a comfortable level.  

For example, let the house cool down in the winter during the day while everyone is at work, and during the night while we're all asleep.  

I'm not talking about turning the HVAC *off*, just letting it do less work by changing the temperature setting so it's closer to the outside temperature but still well within a range that will keep our plants and cats alive, appliances working, etc..  

One of the first things my husband did here was to install a programmable thermostat.  People here, however, seem universally to believe that changing the temperature setting actually uses MORE energy, because the system has to work so much harder to return the house to a comfortable temperature.  

I readily agree that in the morning, for example, our heat runs a lot as it warms the house back up for us.

But, I have to believe that even if it runs steadily for an hour raising the temperature from 62F to 68F, it would have run more than that keeping the house six degrees warmer all night, albeit in smaller increments.
 
Which camp is correct?  Is it possible that we're *both* correct?  Maybe what applies to northern systems such as wood stoves, oil-burning furnaces, and window AC units does not apply to heat pumps (which do seem to be much less efficient) and central AC?
 
Thanks for any insight!
 
Laurie Warner
Greer, SC

What do you think?

[Karsten]

This thread should help. Well, it helped me.

http://www.thenakedscientists.com/forum/index.php?topic=15029.msg270312#msg270312