CALCULATE · COMPARE · UNDERSTAND
Test a practical change. See the energy used and the emissions saved.
YOUR SCENARIO
Factors are illustrative, not official values for a country or year. For a real exercise, enter a suitable local factor in the units shown.
ANNUAL RESULT
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An estimate of annual operational emissions for the activity you enter. CO₂e means carbon dioxide equivalent: greenhouse gases expressed on a common basis. Results cover the boundary of your chosen factor; they are not a complete personal, company or product footprint.
Equipment manufacture, installation, refrigerant leaks, end-of-life and upstream fuel emissions are excluded unless explicitly included in a factor. A lower-emission setup is not necessarily more efficient: compare the same useful service.
The editable defaults — electricity 0.25 kg CO₂e/kWh, gas 0.20 kg CO₂e/kWh fuel, and liquid fuel 2.70 kg CO₂e/litre — are rounded teaching assumptions, with no assigned geography or reporting year. All example equipment values are hypothetical.
For real measurements, use a source matched to your country, year, fuel and boundary. Record that source in your coursework. Do not substitute a CO₂-only factor for a CO₂e factor without changing how you describe the result.
Use average electrical input power measured during operation, not a motor’s mechanical output rating. Running hours must account for cycling and idle periods. Metered annual consumption is preferable when available.
Heating holds useful heat demand constant. Use seasonal efficiency and seasonal heat-pump performance for annual estimates. Match boiler efficiency and the gas factor to the same net or gross calorific-value basis. The simplified comparison excludes additional auxiliary loads.
GHG Protocol calculation tools and guidance ↗
Methods and guidance for constructing an emissions inventory.
SEAI energy conversion factors ↗
An example of a national source. Its published fuel factors are direct CO₂ only; check coverage carefully. These sources are not the source of the calculator’s illustrative defaults.