[Maxburn]

It's an industry term for mechanical equipment that can heat AND cool. One piece of equipment replaces your AC AND heat source.

Heat pumps in particular are getting a push from "green" initiatives because they only use electricity for fuel which can potentially be supplied by "renewable" sources.

ie; it's a buzz word.

[kevin_thibedeau]

It's not just buzz. It's more efficient than resistive heating and modern units have better performance in cold temps. Hence the push to promote them. The downside is that you have added complexity driving up installation costs and reliability down.

[Maxburn]

Walk around in the American Heating and Refrigeration conference for a while to get a feel of these trends, this was specifically called out by many manufacturers as driven by the green movement.

[1-more]

> because they only use electricity for fuel which can potentially be supplied by "renewable" sources.

They also can operate at >100% efficiency. Under the right conditions (I'll let someone who knows more about it fill that in) they can provide more heat than the same amount of power going into a resistive heater (which is I think per-se 100% efficient right?). Kinda wild.

[IanCal]

This should happen under a fairly wide range of temperatures for modern heat pumps. Quoted figures are usually in the 3-4x more efficient than resistive heating when adjusted for seasonality for air source heat pumps. Ground source are more like 5+ I think.

That's lab figures though so I guess similar to car efficiency figures.

[Maxburn]

OR another (incorrect) way of thinking is that resistive heating is 100% efficient as every bit of heat generated is inside the home. VS mechanical heat has some "loss" with some of the heat being left outside the home.

But yes, mechanical might be up to 600% efficient depending on how you think about it as moving heat around based on energy usage per therm delivered inside the home is really what people are looking for.

[jondwillis]

Why put renewable in quotes? Because it isn’t 100%?

[Maxburn]

Basically yes. Renewable is more of a supplement to current grids for most of us. There might be a couple rare few areas that currently claim 100%.