1. What is a Combi Boiler kW Calculator?

Definition: This calculator determines the required power output (in kW) for a combi boiler based on your heating needs in BTU/h.

Purpose: It helps homeowners and heating engineers select the appropriately sized combi boiler for efficient heating and hot water production.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula converts BTU/h to kW (1 kW = 3412 BTU/h) to determine the required boiler size.

3. Importance of Proper Boiler Sizing

Details: Correct boiler sizing ensures efficient operation, prevents energy waste, and provides adequate heating and hot water without short cycling.

4. Using the Calculator

Tips: Enter your calculated heat requirement in BTU/h. The calculator will convert this to the equivalent kW rating needed for your combi boiler.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my heat requirement in BTU/h?
A: Use a heat loss calculation for your property or consult with a heating engineer. Typical UK homes need 25-35 kW combi boilers.

Q2: What's the conversion factor between kW and BTU/h?
A: 1 kW = 3412 BTU/h. This is a fixed conversion factor.

Q3: Should I round up the calculated kW value?
A: Yes, combi boilers come in standard sizes (24kW, 28kW, 32kW, etc.). Round up to the nearest available size.

Q4: Does this include hot water requirements?
A: Yes, for combi boilers this calculation should include both space heating and domestic hot water needs.

Q5: What if I only know my requirements in kW?
A: If you already know your required kW, you don't need this calculator - just select a boiler with that rating.