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_ |
|---|---|---|---|---|---|---|---|
| GSHP, ground at 10 °C | Low output temperature | 7.2 | 5.0 | 3.7 | 2.9 | 2.4 | ‐ |
| Theoretical Carnot cycle limit, source −20 °C |  | 5.6 | 4.9 | 4.4 | 4.0 | 3.7 | 3.4 |
| Theoretical Carnot cycle limit, source 0 °C |  | 8.8 | 7.1 | 6.0 | 5.2 | 4.6 | 4.2 |
| Theoretical Lorentzen cycle limit (CO , 2 pump), return fluid 25 °C, source 0 °C |  | 10.1 | 8.8 | 7.9 | 7.1 | 6.5 | 6.1 |
| Theoretical Carnot cycle limit, source 10 °C |  | 12.3 | 9.1 | 7.3 | 6.1 | 5.4 | 4.8 |