Re:Calgarians detail life with an electricity load limiter
by ars on Monday March 21, 2022 @03:31PM
(#30758639)
Most heating heat pumps I've seen can ramp up/down as demand changes.
Also central heat pumps (for heating) aren't so common, most are mini-split types with each room separate, or at least a highly variable central compressor than can run on low.
Re:Calgarians detail life with an electricity load limiter
by CWuestefeld on Monday March 21, 2022 @03:44PM
(#30758794)
I don't have any factual citations, but I suspect they're a lot more common than you think. At the very least, they're completely ubiquitous in central Texas. I'd imagine that's a combination of temperate conditions (as opposed to Minnesota, it never gets to the 6F temperature here), and newer construction (older houses are probably less likely to have a heat pump anyway, but with the insane growth in real estate around here, there's not very many old houses).
But in many areas an electric heat pump is common. This is a forced-air system, and controlled by zoned thermostats just like traditional gas or oil heat.
That said, such heat pumps actually have multiple states:
* Cooling
* Off
* Heating
* Emergency heat (aka Aux heat)
That last one happens when the ambient temperature is so low that the heat pump can't scavenge enough heat, and needs to augment with resistive heat (which happens through the same forced air delivery). Thus, in extreme cold you may be using even more electricity than you normally would.
I live near Austin. The only time I've seen the Aux Heat in use was during last year's February freeze, which at 6F was the lowest temperature ever recorded here. Even at the occasional 13F-15F temperatures, the heat pump still operates normally (albeit it at very long cycles).