I really like this idea and feel it could be applied much more widely. 1 downstairs (mainly) for heating and 1 upstairs mainly for cooling. As has been said, the heating bit might make a dent in gas consumption in the shoulder season, the cooling just makes life nicer when there is surplus pv available and it is hot outside.Oldgreybeard wrote: ↑Tue Jul 19, 2022 5:35 pm We only have aircon in our bedroom, a DIY split system I installed a couple of years ago. As mentioned earlier, if we leave the bedroom door wide open this does tend to set up a sort of thermosyphon, where warmer air from the hall flows up to the bedroom, with cool air flowing back down the stairs. The air flow is surprisingly high, holding a hand out near floor level on the stairs I can feel the cooler air flowing downwards. Not sure how much it's contributing to the lower temperatures we've had indoors over the past couple of days, as I changed too many things at the same time, but I think it would be fairly effective on its own.
A