407 versus 410

[ukheatpumps]

Can anyone tell me the most efficient refrigerant in ground source heat pump systems,407 or 410?

[monkey spanners]

It would depend on the rest of the system, i would think the COP of the system would be the thing to look at.

Personaly i don't like R407C and would avoid purchasing systems with this in them.

[multisync]

I have been told 410a is better in cooling and 407c better in heating. However that was from a GSHP manufacturer who only supplied 407c kit

[Magoo]

Recently replaced a R22 heat pump at home with a 410A, after huge pressure from her in-doors, as the old unit spent half of its life defrosting on heat cycle.
The performance difference is huge, no more complaints from her in-doors, the cat is also very impressed.
Plus the power billing dropped markedly. The new system was an inverter.
magoo