I've seen several posts stating that a solar heater is operating at peak efficiency when the temperature difference is only 1 or 2 degrees. Is this also true of heat pumps? (I would assume that the physics remain the same, but...) There's about 8' - 10' of pipe between the heater outlet and the return, if that makes any difference. The way it is plumbed, I can raise and lower the flow rate through the heater easily enough by simply partially opening and closing valves if it makes sense to do so. I don't have a flow meter, but it's easy enough to guesstimate. BTW, I have an electric air-source unit.
Also, why does my pool heat pump shut down when the air temp gets around 55 degrees or below? I also have an electric air-source heat pump for the house, and it continues to run until the air temp gets below zero. (Well, actually it continues to run even below zero, but it then turns on the auxiliary heating elements.) It's very unlikely that I'd be swimming if the air temp was below 50 anyway, but I'm curious why the difference. Is it because heating water requires more energy than heating air?
Thanks,
Tim.
Also, why does my pool heat pump shut down when the air temp gets around 55 degrees or below? I also have an electric air-source heat pump for the house, and it continues to run until the air temp gets below zero. (Well, actually it continues to run even below zero, but it then turns on the auxiliary heating elements.) It's very unlikely that I'd be swimming if the air temp was below 50 anyway, but I'm curious why the difference. Is it because heating water requires more energy than heating air?
Thanks,
Tim.