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Daikin Altherma Split

Isle of Wight · Detached · 300 m² · Pre-1900 · 11 kW · underfloor

Last 30 days

704 hourly rows · MID-class heat meter present: yes
1.46efficiency (COP) over 704 hours, from the heat meter
better than 0% of the metered fleet in January 2026
Electricity used
90 kWh
Heat delivered
131 kWh (heat meter)
Estimate without heat meter
flow sensor 2.28 · temperature model 5.24
Mean outdoor temperature
12.3 °C · 17 space-heating hours
Flow temperature at 0 °C outside
11.3 °C (curve slope 1.60 per K)
Flow − return while heating
2.5 K
House needs at −3 °C
-1.0 kW (unit rated 11 kW) · fit r² 0.06
Hot water
33% of electricity, COP 1.49
infoOnly 17 space-heating hours in this window
Space-heating findings need at least 60 hours with the compressor running below 15 °C outside. Choose a winter window or come back during the heating season.
noteOwner’s note on the source site: “Not main heating source or a holiday home, booster heater not metered”
valueReaching the fleet’s January median (3.69) would have saved about £14 in this window at 0.25 GBP/kWh. An estimate, not a promise.

Day by day

electricity per daydaily COP3.0 floor
electricity, kWh per day05102026-10-08: 9.2 kWh, outside 13.2 °C2026-10-09: 9.5 kWh, outside 16 °C2026-10-10: 3.1 kWh, outside 12.4 °C2026-10-11: 3.2 kWh, outside 12.8 °C2026-10-12: 3.4 kWh, outside 15.4 °C2026-10-13: 3.8 kWh, outside 17.5 °C2026-10-14: 4.3 kWh, outside 14.5 °C2026-10-15: 3.5 kWh, outside 17.8 °C2026-10-16: 2.4 kWh, outside 13.4 °C2026-10-17: 4.2 kWh, outside 10.6 °C2026-10-18: 1.3 kWh, outside 10.8 °C2026-10-19: 1.3 kWh, outside 11.8 °C2026-10-20: 1.5 kWh, outside 12.1 °C2026-10-21: 1.3 kWh, outside 10 °C2026-10-22: 1.5 kWh, outside 12.2 °C2026-10-23: 1.3 kWh, outside 10.8 °C2026-10-24: 4.6 kWh, outside 9.8 °C2026-10-25: 9.1 kWh, outside 12 °C2026-10-26: 3.1 kWh, outside 12.8 °C2026-10-27: 1.9 kWh, outside 14.3 °C2026-10-28: 1.6 kWh, outside 12.1 °C2026-10-29: 1.2 kWh, outside 13.6 °C2026-10-30: 1.1 kWh, outside 12.1 °C2026-10-31: 1.3 kWh, outside 11.4 °C2026-11-01: 1.6 kWh, outside 10.2 °C2026-11-02: 1.7 kWh, outside 10.3 °C2026-11-03: 1.7 kWh, outside 10.2 °C2026-11-04: 1.9 kWh, outside 10 °C2026-11-05: 1.9 kWh, outside 9.9 °C2026-11-06: 1.9 kWh, outside 10 °C2026-11-07: 0.7 kWh, outside 5.4 °Cdaily COP (heat ÷ electricity)1352026-10-08: COP 3.362026-10-09: COP 2.812026-10-10: COP 0.472026-10-11: COP 0.562026-10-12: COP 0.622026-10-13: COP 0.772026-10-14: COP 0.662026-10-15: COP 0.792026-10-16: COP 0.552026-10-17: COP 0.652026-10-18: COP 02026-10-19: COP 02026-10-20: COP 02026-10-21: COP 02026-10-22: COP 02026-10-23: COP 02026-10-24: COP 1.612026-10-25: COP 3.32026-10-26: COP 5.752026-10-27: COP 0.152026-10-28: COP 0.012026-10-29: COP 02026-10-30: COP 02026-10-31: COP 02026-11-01: COP 02026-11-02: COP 02026-11-03: COP 02026-11-04: COP 02026-11-05: COP 02026-11-06: COP 02026-11-07: COP 010-0810-1210-1610-2010-2410-2811-0111-05
Daily COP needs a heat meter; days without one show electricity only.
Public system published by its owner on HeatpumpMonitor.org. Cycling (starts per hour) comes from the site’s 365-day statistic. Findings use installer rules of thumb; see methodology.