Heating energy comparison

Enter the useful heat delivered to the building per year, not the electricity or fuel bought. Use the same currency for every price. Currency labels amounts; it does not convert rates. Prices, energy contents, efficiencies and CO₂ factors are illustrative, not current tariffs or certified equipment data.

For boilers and resistance heating, efficiency is useful heat divided by purchased energy (0–100%, same calorific basis). For a heat pump use the seasonal ratio of delivered heat to electricity, e.g. 3.5, rather than 350%. A single instantaneous COP is not an annual seasonal factor.

Useful kWh per unit = energy content × efficiency/100; for a heat pump multiply by its seasonal factor. Purchased units = useful heat demand / useful kWh per unit. Annual cost = purchased units × price. The table is ordered by annual fuel cost; installation, fixed charges, maintenance and financing are excluded. Equal costs and zero demand do not pick an arbitrary cheapest source.

Open assumptions to adapt energy contents and optional CO₂ factors per purchased unit. Use supplier data on a consistent calorific basis; efficiencies above 100% based on lower heating values must be converted to the chosen basis. Unknown factors stay blank. Wood combustion emits biogenic CO₂: the old zero factor was removed. Other example factors are approximate, and electricity is an example mix, not your grid. Consumption & CO₂ shows amounts, direct fuel combustion or electricity generation; no lifecycle footprint, CH₄/N₂O or carbon-neutrality claim. Changing an input clears old output. Inputs, currency and open assumptions are saved locally on this browser, including unfinished entries. Recalculate after reloading; results are not restored.