1. What is a Combi Boiler Size Calculator?

Definition: This calculator estimates the required combi boiler size in kilowatts (kW) based on the heating load in British Thermal Units per hour (BTU/h).

Purpose: It helps homeowners and heating engineers determine the appropriate boiler size for efficient heating system performance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Boiler size in kilowatts
• \( Q_{btu} \) — Heating load in BTU per hour

Explanation: The formula converts the heating requirement from BTU/h to kW, where 3412 BTU/h equals 1 kW.

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 property's heating load in BTU/h. The value must be > 0. For best results, get a professional heat loss calculation.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my heating load?
A: You can use a heat loss calculator or consult a heating engineer for a professional assessment.

Q2: What's a typical boiler size for UK homes?
A: Most UK homes require 24-30kW combi boilers, but this varies based on property size and insulation.

Q3: Why convert from BTU to kW?
A: UK boiler specifications are typically in kW, while some heat loss calculations provide results in BTU.

Q4: Should I round up the boiler size?
A: Yes, it's common practice to round up to the nearest standard boiler size available.

Q5: Does this account for hot water demand?
A: This calculation is for heating only. Combi boilers should be sized to meet both heating and hot water needs.