1. What is a Central Heating Boiler Size Calculator?

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

Purpose: It helps homeowners and HVAC professionals determine the appropriate boiler capacity for efficient heating system design.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Boiler size (kilowatts)
• \( Q_{btu} \) — Heat output (BTU per hour)

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 energy efficiency, proper heating capacity, and prevents short-cycling or insufficient heating.

4. Using the Calculator

Tips: Enter the total heat output in BTU/h (calculated from room sizes, insulation, and climate factors). The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my heat output needs?
A: Calculate based on room dimensions, insulation quality, and local climate, or consult a heating professional.

Q2: Why is 3412 the conversion factor?
A: It's the exact conversion between BTU/h and kW (1 kW = 3412.142 BTU/h).

Q3: Should I round up the boiler size?
A: Typically yes, to the nearest standard boiler size, but consult with an HVAC professional for your specific needs.

Q4: Does this account for hot water needs?
A: No, this calculates heating capacity only. Add 3-5 kW if the boiler also provides domestic hot water.

Q5: What's a typical BTU/h requirement for a house?
A: A well-insulated 2,000 sq ft home might need 60,000-80,000 BTU/h in a cold climate.