16 October was the first day since the temperature dropped to 20 degrees.Since then the lowest internal temperature as monitored by the Boots sensor is 19 degrees.
Again the house was maintaining a very comfortable temperature. I hadnt really understood the importance of solar gain. It is quite extraordinary as once the sun appears even if its only for a couple of hours it has a dramatic and long last impact. The internal temperature will rise to 21/22 degrees and the house will maintain this as the temperature start to drop outside.
This screenshot from my Oregon shows the temperature outside at 7:31 AM at 5.4 and inside at 20 degrees.
The worse days are the dull, cloudy and overcast days. There is little solar gain to be had so the house temperature doesnt get a boost. It also impacts he Solar Hot Water tank.