1. What is a Boiler Size Calculator?

Definition: This calculator determines the appropriate boiler size based on a building's heat loss and the heating system's efficiency.

Purpose: It helps HVAC professionals and homeowners select a properly sized boiler for efficient heating.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Required boiler size (kW)
• \( H \) — Building heat loss (kW)
• \( E \) — System efficiency (dimensionless, 0-1)

Explanation: The heat loss is divided by system efficiency to determine the minimum boiler output needed to maintain comfortable temperatures.

3. Importance of Proper Boiler Sizing

Details: Correct sizing ensures energy efficiency, prevents short cycling, maintains comfort, and extends equipment life.

4. Using the Calculator

Tips: Enter the building's heat loss in kW and system efficiency (default 0.85 for 85% efficiency). Efficiency must be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my building's heat loss?
A: Conduct a professional heat loss calculation or use our Heat Loss Calculator tool.

Q2: What's a typical efficiency for modern boilers?
A: Condensing boilers typically have 90-95% efficiency, while older systems may be 70-85% efficient.

Q3: Should I round up the boiler size?
A: Yes, select the next available standard boiler size above your calculated value.

Q4: Does this include domestic hot water needs?
A: No, this calculates space heating requirements only. Add 3-5kW for hot water if needed.

Q5: What if my boiler is oversized?
A: Oversized boilers operate less efficiently, cycle more frequently, and have shorter lifespans.