CO2 Heat Pump Efficiency
Figure 4. Efficiency of CO2 heat pump as a function of ambient temperature (domestic hot water application).
- The efficiency is routinely higher than equivalent HFC heat pumps in domestic hot water application.
- The increase in COP is roughly fixed across non-freezing ambient temperatures. This means that the relative efficiency benefit increases as the ambient temperature drops towards zero.
- The maximum hot water temperature achieved by the CO2 system is higher than that for the HFC system.