Heat pump Performance COP variation with output temperature

| Pump_type_and_source | Typical_use | _35_C_e_g_heated_screed_floor | _45_C_e_g_heated_screed_floor | _55_C_e_g_heated_timber_floor | _65_C_e_g_radiator_or_DHW | _75_C_e_g_radiator_and_DHW | _85_C_e_g_radiator_and_DHW_ |
|---|---|---|---|---|---|---|---|
| High-efficiency air source heat pump (ASHP), air at −20 °C |  | 2.2 | 2.0 | ‐ | ‐ | ‐ | ‐ |
| Two-stage ASHP, air at −20 °C | Low source temperature | 2.4 | 2.2 | 1.9 | ‐ | ‐ | ‐ |
| High efficiency ASHP, air at 0 °C | Low output temperature | 3.8 | 2.8 | 2.2 | 2.0 | ‐ | ‐ |
| Prototype transcritical CO , 2 (R744) heat pump with tripartite gas cooler, source at 0 °C | High output temperature | 3.3 | ‐ | ‐ | 4.2 | ‐ | 3.0 |
| Ground source heat pump (GSHP), water at 0 °C |  | 5.0 | 3.7 | 2.9 | 2.4 | ‐ | ‐ |