Boiler Size Formula:
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Definition: This calculator determines the appropriate boiler size needed for a home based on heat loss and system efficiency.
Purpose: It helps homeowners and heating professionals select a properly sized boiler for optimal performance and energy efficiency.
The calculator uses the formula:
Where:
Explanation: The total heat loss is divided by the boiler's efficiency to determine the required boiler output capacity.
Details: Correct boiler sizing ensures efficient operation, prevents short cycling, maintains comfort, and extends equipment lifespan.
Tips: Enter the total heat loss (from a heat loss calculation) in kW and the boiler efficiency (default 0.85 for 85% efficient boilers). Efficiency must be between 0 and 1.
Q1: How do I determine my home's heat loss?
A: Conduct a professional heat loss calculation or use our Heat Loss Calculator tool.
Q2: What's a typical efficiency for modern boilers?
A: Modern condensing boilers typically have 90-95% efficiency (0.9-0.95), while older boilers may be 70-85% efficient.
Q3: Should I round up the boiler size?
A: It's common to round up to the nearest standard boiler size, but avoid significantly oversizing.
Q4: Does this include domestic hot water needs?
A: No, this calculates space heating requirements only. Add 3-5 kW if the boiler will also provide hot water.
Q5: What if I have multiple heating zones?
A: The heat loss should represent the total for all zones combined.