[grover432]

We have a radiant heat hot water system in our house. It is heated with a natural gas Weil McLain high efficiency boiler (2008). We are going away for 2 weeks and have traditionally lowered the temperature in the house to +13C while we are away.

Some people have suggested that there is no energy savings with turning the heat that low and I should only turn the heat down a few degrees. I can see teh argument if I let the heat drop that low overnight, but if we are away for two weeks, it seems that the lower the heat the better.

Has someone does a study of this or have a link to a resource that has studied the issue? We are leaving tomorrow and I neglected to call our utility provider (they are closed for the weekend now).

We live on the prairies with overnight lows expected to be -20C and daytime highs -15C.

Thanks

 

[grover432]

No house plants and we have a low temp sensor in our centrally monitored alarm system so if there is a low temp warning we'll get notice and have a local person let the heating company in the house.

Do you know of any resources that discuss the issue. My sister in law (the expert - self proclaimed) says that the energy used to raise the house back up from 13C to 22C outweighs just lowering the temp from 22C to 18C and then turning it back up when we get home.

 

[grover432]

57, I see your point. I just got off the phone with a friend of mine who is an electrical engineer. He said it is a very good question for the mechanical engineering department at his firm (no real help today). He says they wrestle with this on commercial buildings all of the time.

Part of the issue is how much energy it will take to reheat the air, but the bigger question is how much energy will it take to reheat the structural materials that have dropped to 13C. The plaster, drywall, wood flooring, carpet, etc. All of this material absorbs heat during the heating season and will lose heat when you cool the house down.

If the house never needed to be warmed up again (i.e. if you left it a 13C until spring), then I agree that the lower the better, because you wouldn't have to heat the structure up to 22C. But we will when we return in 2 weeks, so that is the reason for the question ...