Heat demand result
Estimated peak heat demand
63.8 kW
Indicative annual heat delivered
114,300 kWh
Recommended system types
Air-to-water heat pump with low-temperature emitters, modular condensing gas boiler, warm air heating for taller open-plan zones.
| Option | Annual running cost | Annual CO₂ | Comment |
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Budgeting note
Taller spaces, poor insulation, and long operating hours push commercial heating costs upward very quickly, so the most important design step is usually reducing unnecessary heat demand before selecting plant.
How to use this estimator
1. Set the fabric and volume
Floor area and ceiling height together tell you much more than area alone. Double-height or high-bay spaces can need significantly more heat, especially where stratification and infiltration are present.
2. Compare energy options
Use the output table to compare the delivered heat cost of gas, direct electric heating, and heat pumps, rather than comparing tariffs in isolation.
3. Sense-check the shortlist
The best system depends on occupancy profile, zoning, emitter type, ventilation losses, and whether the building needs warm air response or steady low-temperature heating.
Methodology
How the commercial heat demand is estimated
The calculator starts with a space-type heat intensity benchmark expressed as watts per square metre under normal commercial winter design conditions. Offices and retail spaces sit in the middle of the range, warehouses rise once height and door losses are considered, workshops need extra allowance for intermittent ventilation and fabric losses, and restaurants run higher due to longer occupied hours and comfort expectations.
Ceiling height is then used as a practical volume multiplier, while insulation quality and region adjust the peak demand up or down. Occupancy hours do not directly change the design-day peak load, but they do affect the estimate of annual delivered heat because a building heated for 16 hours a day will use more energy across a season than one heated for 8 hours a day.
Annual running costs are calculated using indicative UK commercial energy assumptions based on the tariff inputs requested: gas at 6.24p/kWh and electricity at 24.50p/kWh. Heat pump running cost assumes useful seasonal performance rather than direct one-to-one electricity conversion, with COP adjusted modestly by building type and ceiling height.
Carbon values are estimated from delivered fuel use using factors of 0.203kg CO₂/kWh for gas and 0.207kg CO₂/kWh for electricity. This tool is intended for early budgeting and strategic comparison. Final system design should account for ventilation rates, setpoint temperatures, occupancy zoning, emitter temperatures, domestic hot water where relevant, and any process loads not captured here.
Products worth considering
Based on your results, these product categories may be relevant to your next step.