[steve86]

Hi, it just so happens that the city has a program to seal ducting right now (taxpayer paid), so that's going to be done in a couple weeks, but as I mentioned earlier it will be one of the few times the blower will have been turned on this winter when they test for leaks. Oh well, it should help with summer A/C also. But no way you can avoid at least some radiational losses through the ducts even if sealed against physical leakage.

One somewhat interesting thing I learned from the DeLonghi space heater experiment is how much energy was needed to maintain a steady state temperature (68F) in the house with an outdoor temp of low 20s day and night. Turns out it is around 2.7 kilowatts @ about 6 cents/kwh. Not bad for a 1973 doublewide? LOL

[steve86]

Of course, the people in the house and other energy-consuming appliances add BTUs as well. But then there are things like exhaust fans and infiltration that take it out.