Viewing a single comment thread. View all comments

quintus_horatius t1_j1a6369 wrote

Reply to comment by Bunslow in Why do we use phase change refrigerants? by samskiter

You only have a few options for heat, and only one that can exceed 100% efficiency - a heat pump.

A typical heat pump exceeds 2.5, a good heat pump exceeds 3.0, and a fantastic heat pump approaches 4.0.

The latter generally show up in highly specialized applications like geothermal, where you can tailor your working fluid to a narrow, predictable temperature range.

2

Bunslow t1_j1ajqfp wrote

cool, so 2.5-3 is totally achievable for residential/end consumer purposes. is that what residential air conditioners achieve as well?

1

seven_tech t1_j1assin wrote

Mine almost does.

It uses a maximum of 1.9kW of electricity to move up to 5.2kW of heat in best circumstances. That's a CoP of 2.74. And it's definitely not as efficient as they get.

3

samskiter OP t1_j1co3h0 wrote

There are residential heat pumps with SCOP (seasonal cop) of 5.

1