Cold weather Duers, what do you set your thermostat at during the day and at night?

[zipplewrath]

35. Bingo

Large changes in temperature, especially over short periods of time aren't "efficient". Programable thermostats should be used to avoid "chasing peaks". When it's warm, you want to allow the peak to pass without fighting it. So if the house will naturally peak out at 84 during the day, and then settle back to 80 by 6pm, you might consider allowing that, and then starting stronger cooling at 6 pm to get it down to whatever you want it to be for evening/night.

With heating, you want the whole house to stay as close to some target temperature as possible. Small incremental changes are the most efficient way to heat things. So you can let it "cool down" a little at night, but at somepoint you want to start heating up the house very slowly. So suppose you want the house at 68 when you arise at 7 am. You'd want to program the thermostat to heat the house up about 1 degree every hour. So depending how low it will go during the night, you'll have to back calculate when to start heating the place back up. But if you lose 2 degree per hour out of the house, it will take you twice as long to heat it back up. So in 3 hours you'll lose 6 degrees, and it will take you 6 hours to "get it back". So you could let it start cooling down an hour before going to bed, and then 3 hours later, start warming it back up.

Probably not a great saver. Better to just let it drop a couple of degrees during the night and then a couple of hours prior to rising, have it come back up.

What's buried in all these numbers is the value and reality of "stored heat". Huge thrermal masses are a great way to maintain the heat of the house. Brick walls, tile floors, thick insulation, these are very useful and effective because they maintain a constant temperature and represent slow, incremental changes in the temperature of the home. Slow and incremental is the most efficient way. Blasting the AC or heat to "quickly" warm things up is the LEAST efficient way to get the job done.

Oh, and to answer the original question, we tend to leave the thermostat at 64. I've got thick socks and I drink hot tea. Lots of throws around the house as well. My hand does often get cold on the mouse though.