1. What is a Boiler Size Calculator?

Definition: This calculator determines the required boiler size in kilowatts (kW) based on the heat load of a house in BTU/h.

Purpose: It helps homeowners and HVAC professionals select the appropriately sized boiler for efficient heating.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_{kW} \) — Boiler size in kilowatts
• \( Q_{btu} \) — Heat load in BTU per hour
• 3412 — Conversion factor (BTU/h to kW)

Explanation: The heat load in BTU/h is converted to kilowatts by dividing by 3412 (since 1 kW = 3412 BTU/h).

3. Importance of Proper Boiler Sizing

Details: Correct boiler sizing ensures efficient operation, prevents energy waste, and extends equipment lifespan. Oversized boilers cycle more frequently, while undersized ones can't meet demand.

4. Using the Calculator

Tips: Enter the heat load of your house in BTU/h. This value can be obtained from a Manual J calculation or from your HVAC professional.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my home's heat load?
A: A professional energy assessment or Manual J calculation provides the most accurate heat load measurement.

Q2: What's a typical heat load for a house?
A: A well-insulated 2,000 sq ft home might need 40,000-60,000 BTU/h, but this varies by climate and insulation.

Q3: Why convert to kW when boilers are often rated in BTU?
A: Many modern boilers (especially in Europe) are rated in kW, and this provides a standardized measurement.

Q4: Should I round up the boiler size?
A: It's common to add 10-20% to the calculated size for safety margin, but consult an HVAC professional.

Q5: Does this account for domestic hot water needs?
A: No, this calculates space heating needs only. Add 20-30% if the boiler will also provide domestic hot water.