Traveling with the furnace running

beemerphile1 wrote:

Padlin wrote:
I don't understand the "sucking the heat out", have you tried it?

Thought it would take an hour to heat it up, will try it on a cold day at home.

Thanks

In still air, a structure has an envelope of slightly warmer air around the outside. Driving down the road will prevent that envelope from forming and the moving air will literally suck the heat out much worse than if parked.