1. What is Heat Pump Sizing?

Heat pump sizing refers to determining the appropriate capacity (in kW) of a heat pump needed to efficiently heat your property based on its size and heat loss characteristics, following UK government guidelines.

2. How Does the Calculator Work?

The calculator uses the standard UK government formula:

Where:

• \( Area \) — Total floor area of the property in square meters
• \( Factor \) — Heat loss factor (typically 50-100 W/m²)
• \( kW \) — Recommended heat pump size in kilowatts

Explanation: The calculation estimates the heat energy required to maintain comfortable temperatures based on property size and insulation quality.

3. Importance of Correct Sizing

Details: Proper sizing is crucial for energy efficiency, system longevity, and comfort. An undersized unit will struggle to heat the property, while an oversized unit will cycle frequently, reducing efficiency.

4. Using the Calculator

Tips:

• Measure total heated floor area (excluding garages/outbuildings)
• Use 50-60 W/m² for well-insulated modern homes
• Use 70-80 W/m² for average insulation
• Use 90-100 W/m² for older, poorly insulated properties

5. Frequently Asked Questions (FAQ)

Q1: Why use this calculation method?
A: This is the standard method recommended by UK government and industry bodies for initial sizing estimates.

Q2: What if my property has unusual features?
A: For properties with high ceilings, large windows, or other unique features, a professional heat loss calculation is recommended.

Q3: Does this account for hot water needs?
A: This calculation is for space heating only. Add 1-2 kW to the total if the heat pump will also provide domestic hot water.

Q4: What about climate variations in the UK?
A: The factors already account for typical UK climate conditions. Colder regions may need slightly higher factors.

Q5: Should I get a professional assessment?
A: Yes, this calculator provides an estimate only. Always consult with an MCS-certified installer for final sizing.