1. What is a Heat Only Boiler Size Calculator?

Definition: This calculator determines the appropriate size of a heat-only boiler based on the heat demand of a property and a safety factor.

Purpose: It helps heating engineers and homeowners select a properly sized boiler for efficient operation and optimal performance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Boiler Size — Required boiler output in kilowatts (kW)
• Heat Demand — Calculated heat requirement of the property (kW)
• Safety Factor — Multiplier to account for heat loss and system inefficiencies (typically 1.2)

Explanation: The heat demand is multiplied by a safety factor to ensure the boiler can meet the property's requirements under all conditions.

3. Importance of Proper Boiler Sizing

Details: Correct boiler sizing ensures energy efficiency, reduces wear and tear, prevents short cycling, and maintains comfort levels.

4. Using the Calculator

Tips: Enter the heat demand in kW and safety factor (default 1.2). The heat demand should be calculated through a proper heat loss calculation.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my property's heat demand?
A: Conduct a heat loss calculation considering insulation, room sizes, windows, and outdoor temperatures.

Q2: Why use a safety factor of 1.2?
A: This accounts for system inefficiencies and ensures the boiler can meet demand during very cold weather.

Q3: What happens if I oversize my boiler?
A: Oversized boilers operate less efficiently, cycle more frequently, and have shorter lifespans.

Q4: Can I use this for combi or system boilers?
A: This calculator is specifically for heat-only boilers. Other types require additional considerations.

Q5: Should I round up the boiler size?
A: Choose the nearest standard boiler size above your calculated requirement.