Calculate Your Room's BTU
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Height (m)
BTU (British Thermal Unit) is the standard measure of heat output for radiators. The higher the BTU, the more heat the radiator produces. Always size your radiator to at least match your room's BTU requirement.
A poorly insulated room loses heat quickly. A well-insulated room retains heat, meaning you need a lower BTU output to maintain a comfortable temperature.
For larger rooms, you can split the total BTU across two or more radiators. This is often preferable to one very large radiator.
All radiator heat outputs are quoted at ΔT50: a 70°C flow, 50°C return, and 20°C room temperature. If you run a lower temperature system (e.g. heat pump), you'll need a higher BTU radiator.
Not sure? Our heating experts are on hand for a free heat loss assessment.
📞 Call 01257 452 879