1. What is a Boiler Size Calculator for UK?

Definition: This calculator converts the heat output requirement from BTU/h to boiler size in kilowatts (kW), which is the standard measurement used in the UK.

Purpose: It helps homeowners and heating engineers determine the appropriate boiler size for UK properties based on heat demand.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Boiler size in kilowatts (kW)
• \( Q_{btu} \) — Heat output requirement in British Thermal Units per hour (BTU/h)

Explanation: The formula converts BTU/h to kW using the conversion factor 3412 BTU/h = 1 kW.

3. Importance of Proper Boiler Sizing

Details: Correct boiler sizing ensures efficient operation, prevents energy waste, and maintains comfort while avoiding short cycling or insufficient heating capacity.

4. Using the Calculator

Tips: Enter the heat output requirement in BTU/h (typically calculated from room sizes, insulation levels, and other factors). The calculator will provide the equivalent boiler size in kW.

5. Frequently Asked Questions (FAQ)

Q1: Why convert BTU/h to kW for UK boilers?
A: The UK heating industry uses kilowatts (kW) as the standard measurement for boiler output capacity.

Q2: What's a typical BTU/h requirement for a UK home?
A: A small flat might need 18,000-27,000 BTU/h (5-8 kW), while a large detached house might need 68,000+ BTU/h (20+ kW).

Q3: How do I find my heat output requirement?
A: Use a heat loss calculation that considers room sizes, insulation, windows, and other factors, or consult a heating engineer.

Q4: Should I round up the calculated kW size?
A: Boilers come in standard sizes (e.g., 24kW, 30kW). Choose the next available size above your calculation.

Q5: Does this account for hot water demand?
A: No, this is just for heating. For combi boilers, you'll need to consider both space heating and domestic hot water requirements.