Independent energy/ CALCULATOR
Estimate heat and input energy for a known water volume and temperature rise.
FROM ESTIMATE TO ACTION
Enter the litres actually heated, not automatically the nominal tank capacity. Temperature rise is final minus initial temperature: 10°C to 50°C means 40°C, not 50°C. These temperatures illustrate subtraction, not recommended settings. Use documented or safely available readings; do not open a hot or pressurised tank to measure. Different volumes or temperature rises need separate calculations before adding their heat.
For 100 L and a 40°C rise, useful heat is 4.65 kWh. Enter 90 for 90% efficiency, not 0.90: input energy is about 5.17 kWh. At 50% it is 9.30 kWh, while heat delivered to the same water stays 4.65 kWh. Use a documented efficiency applicable to the heating process; this input accepts 1–100%. Neither the default nor a comparison value is a measured rating for your appliance.
kWh is energy, not heater power in kW. This result does not determine heating time or recovery rate. The model uses about 1 kg per litre and constant specific heat for liquid water, with no boiling or phase change. Tank, pipe and standby losses are not added separately: even zero temperature rise can coexist with real standby energy use. Do not use this estimate to set safe storage temperatures, select electrical protection or predict a complete household bill.