1. What is a Boiler Size Calculator?

Definition: This calculator estimates the required boiler size in kilowatts (kW) based on your home's heat requirement in BTU/h.

Purpose: It helps UK homeowners and heating engineers determine the appropriate boiler capacity for efficient heating.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Boiler power output (kilowatts)
• \( Q_{btu} \) — Heat requirement (BTU per hour)
• 3412 — Conversion factor from BTU/h to kW

Explanation: The heat requirement is converted from British Thermal Units per hour to kilowatts.

3. Importance of Correct Boiler Sizing

Details: Proper boiler sizing ensures energy efficiency, adequate heating capacity, and prevents short cycling or insufficient heating.

4. Using the Calculator

Tips: Enter your home's total heat requirement in BTU/h. The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my home's heat requirement?
A: A heating engineer can perform a heat loss calculation, or you can estimate based on home size (e.g., 30-40 BTU/sq ft for UK homes).

Q2: Why is boiler sizing important?
A: Oversized boilers waste energy and wear out faster, while undersized boilers can't maintain comfortable temperatures.

Q3: What's the typical boiler size for UK homes?
A: Most UK homes need 24-30kW combi boilers, but this varies by property size and insulation.

Q4: Does this include hot water requirements?
A: This calculates heating needs only. For combi boilers, add 3-5kW for hot water capacity.

Q5: Should I round up the calculated size?
A: It's recommended to choose the next available standard boiler size above your calculation.