text:  that the outside temperatures only make it partway into the center of that wall, and the inside temperatures only make it partway into the center of the wall. And that battle between the outside temperature and the inside temperature is taking place in the middle of the wall. You don't want the outside temperature to make it all the way through to the inside, and then the conditioned space is having to make up for that. You want the passive insulation to try to do as much of that work as possible.