> We have efficient heat pumps and solar panels, but it's still a disturbing amount of energy usage and something I'm trying to debug. Perhaps we have too many windows letting in too much sunlight... External window blinds work wonders with that - your AC doesn't have to work hard to get the heat out of the greenhouse you inadvertently built if you avoid the heat getting in in the first place. But yeah, these might b…
It turns out at installation time the installer set all the fans on "high", and I left them that way stupidly thinking: "Well, I like circulation, and the power meters show the fans aren't actually using much power, so I'll just leave it like that."
Changing them all to "auto" fixed the problem.
It turns out that while the fans themselves weren't using a ton of power, their activity caused the heat pumps feeding them to work harder. In retrospect it seems not that surprising and I feel pretty dumb about it.
(And yes there are a lot of windows but they are not south-facing and they are all tinted in a way that blocks most of the sun's energy.)