Home / system #848

Daikin Altherma 3

South Devon · Detached · 179 m² · 1940 to 1982 · 11 kW · radiators · installed by CB Heating

Last 30 days Last 7 days 5 Jan – 4 Feb 2026 (winter reference)1–31 Dec 2025

Last 7 days

169 hourly rows · MID-class heat meter present: yes

2.92efficiency (COP) over 169 hours, from the heat meter
better than 7% of the metered fleet in January 2026

Electricity used: 146 kWh
Heat delivered: 425 kWh (heat meter)
Estimate without heat meter: flow sensor 2.43 · temperature model 3.66
Mean outdoor temperature: 8.9 °C · 76 space-heating hours · cooling 3 kWh removed (1 kWh electricity), kept out of the COP
Flow temperature at 0 °C outside: 36.6 °C (curve slope 0.03 per K)
Flow − return while heating: 3.0 K
House needs at −3 °C: 5.9 kW (unit rated 11 kW) · fit r² 0.00
Hot water: 17% of electricity, COP 2.23

seriousWinter efficiency 2.92 is below the 3.0 floor used for German subsidies

Ask the installer for a commissioning check; the causes are usually flow temperature, hot water settings, or sizing, all listed below.

valueReaching the fleet’s January median (3.69) would have saved about £8 in this window at 0.25 GBP/kWh. An estimate, not a promise.

Day by day

electricity per daydaily COP3.0 floor

Daily COP needs a heat meter; days without one show electricity only.

The installed heating curve

one heating hourfitted curve50 °C

Each point is one hour of space heating. Lower and flatter is cheaper; well-set radiator systems sit around 35–42 °C at 0 °C outside.

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.