Interesting. I read up more on PCMs.<p>The challenge I&#x27;ve had is keeping the house warm in the winter where internal temps will drop down to the 50s without the heater on. During the summer, I rarely have to turn on the AC even when it&#x27;s a 100+ day so there&#x27;s plenty of insulation. I suspect much of the heat loss is due to the giant windows that I have even though they are double pane.