1. What is an Air Source Heat Pump Calculator?

Definition: This calculator estimates the required heat pump capacity in BTU/h based on room area, heat loss per square foot, and a correction factor.

Purpose: It helps homeowners and installers determine the appropriate size of air source heat pump for UK properties.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat pump capacity (BTU/h)
• \( A \) — Area to be heated (square feet)
• \( BTU/ft^2 \) — Heat loss per square foot (BTU/h·ft²)
• \( F \) — Correction factor for insulation and climate

Explanation: The area is multiplied by typical heat loss values, then adjusted for specific property characteristics.

3. Importance of Proper Sizing

Details: Correct heat pump sizing ensures efficient operation, prevents short cycling, and maintains comfort while minimizing energy costs.

4. Using the Calculator

Tips: Enter the area in square feet, heat loss value (default 20 BTU/h·ft²), and correction factor (default 1.2). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical BTU/ft² value for UK homes?
A: For moderately insulated UK homes, 20 BTU/h·ft² is common. Poor insulation may require 25-30, while well-insulated homes may need 15-18.

Q2: How do I determine the correction factor?
A: Use 1.0 for well-insulated homes, 1.2 for average, and 1.4+ for poorly insulated properties or colder regions.

Q3: Should I include all floors in the area?
A: Yes, include the total heated floor area of all levels being served by the heat pump.

Q4: How does this differ for different heat pump types?
A: Air-to-air and air-to-water systems use similar calculations, but water systems may need slightly higher capacity.

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