1. What is a Boiler Size Calculator?

Definition: This calculator determines the required boiler size based on peak heat demand and system efficiency.

Purpose: It helps HVAC professionals and engineers properly size boilers for heating systems to ensure adequate capacity.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Boiler size (kW)
• \( P \) — Peak heat demand (kW)
• \( E \) — Boiler efficiency (dimensionless, 0-1)

Explanation: The peak heat demand is divided by the boiler efficiency to determine the required boiler output capacity.

3. Importance of Proper Boiler Sizing

Details: Correct boiler sizing ensures energy efficiency, prevents short cycling, and provides adequate heating capacity while avoiding oversizing.

4. Using the Calculator

Tips: Enter the peak heat demand in kW and boiler efficiency (default 0.85). Efficiency must be between 0 and 1 (typically 0.8-0.95 for modern boilers).

5. Frequently Asked Questions (FAQ)

Q1: How do I determine peak heat demand?
A: Calculate heat loss for the building or consult HVAC design manuals. For rough estimates, allow 50-150W per m² depending on insulation.

Q2: What's a typical boiler efficiency?
A: Modern condensing boilers typically have 90-95% efficiency (0.9-0.95), while older boilers may be 70-85% efficient.

Q3: Should I add a safety factor?
A: The calculator provides exact sizing. For safety margins, add 10-20% to the calculated size depending on application.

Q4: Does this work for all boiler types?
A: Yes, the formula applies to gas, oil, and electric boilers - just adjust the efficiency value accordingly.

Q5: How does boiler size relate to fuel consumption?
A: Larger boilers consume more fuel, but proper sizing ensures optimal efficiency. Actual consumption depends on runtime and load.