Programmable Thermostat... I thought you were supposed to set the temp and leave it alone?

Question

I do not have a programmable thermostat, and I was told to set my the thermostat to the desired temperature and leave it alone. I thought it wasted more energy when your unit has to heat up a cold house or cool down a hot house.

Don't these thermostats do just that and wouldn't that lead to higher energy bills?

Answer 1

As they say there is some truth in everything. The new digital t-stats are usually more accurate than the old ones.Higher end programmable ones let you set the temp. for so many hours each day and even adjust for weekends when you won't be home.If you are comfortable at 72 degrees you may save by setting the t-stat at 75 while you are at work and have it return to 72 an hour before you come home.Where people go wrong is setting at 80 or turning it off while at work,then expecting it to cool down when they get home.That doesn't work.With most homes it can take several hours to cool down 10 degrees. remember you are cooling the home and contents such as furniture.I have a good friend who is a mechanical engineer. He says the programmable saves money with out a doubt. If you save 20-30 dollars a month that's worthwhile.I use one myself and our heating and cooling bills are 30 to 50 dollars less than most of my neighbors.But you have to be reasonable with the settings.

Answer 2

Turning things off saves energy. The more time off the more energy you save over leaving it at a set temp all the time.

In reality it does NOT cost more to heat or cool a house after being off.

That said, then you have the human factor. The problem that occurs is that when people come home to a cold house they tend to turn the thermostat well above the desired temp because every thing in the house is cold, feels cold.

Say if you want 70 and you come home and it is 60 in the house people will turn it up to 75 until they FEEL warm then later turn it down to the 70 that is comfortable.

It is during the time they turn it up too high ( or very low for cooling) that you use more energy because the more extreme temps cause higher heat loss or gain for cooling.

With programmables you can set them to come on an hour or so before you are home and that avoids the problem of being uncomfortable.

Having them off saves energy if you don't turn them too high when you return. But most people do just that. That is why they say to leave it.