1. What is an Underfloor Heating Boiler Size Calculator?

Definition: This calculator determines the appropriate boiler size needed for an underfloor heating system based on total heat loss and system efficiency.

Purpose: It helps homeowners and heating professionals select the correctly sized boiler for efficient and effective underfloor heating.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Boiler Size — Required boiler capacity in kilowatts (kW)
• Total Heat Loss — Calculated heat loss of the space in kW
• System Efficiency — Efficiency factor of the heating system (0-1)

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

3. Importance of Proper Boiler Sizing

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

4. Using the Calculator

Tips: Enter the calculated total heat loss of your space (in kW) and the system efficiency (default 0.85 for most modern systems). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine my total heat loss?
A: Heat loss calculations consider building insulation, window quality, floor area, and climate. Professional heat loss surveys are recommended.

Q2: What's a typical efficiency value?
A: Modern condensing boilers typically have 0.85-0.92 efficiency, while older systems may be 0.7-0.8.

Q3: Should I add a safety margin?
A: It's common to add 10-20% to the calculated size for extreme weather conditions and future extensions.

Q4: Does this work for both electric and gas boilers?
A: Yes, the calculation applies to all boiler types, though efficiency values may differ.

Q5: What if I have multiple heating zones?
A: The calculator still works as long as you input the combined heat loss of all zones.