Heat Pump Sizing Calculator UK

Heat Pump Sizing Formula:

\[ \text{Size} = \frac{\text{Heat Loss}}{\text{COP}} \]

Heat Pump Size (kW):

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1. What is a Heat Pump Sizing Calculator?

Definition: This calculator estimates the required size (capacity) of a heat pump based on your property's heat loss and the system's Coefficient of Performance (COP).

Purpose: It helps homeowners and installers determine the appropriate heat pump size for efficient heating in UK properties.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \text{Size} = \frac{\text{Heat Loss}}{\text{COP}} \]

Where:

Size — Required heat pump capacity (kW)
Heat Loss — Your property's heat loss (kW)
COP — Coefficient of Performance (typically 3.0-4.0 for UK heat pumps)

Explanation: The heat loss is divided by the COP to determine the heat pump size needed to maintain comfortable temperatures efficiently.

3. Importance of Correct Heat Pump Sizing

Details: Proper sizing ensures optimal efficiency, prevents short cycling, maintains comfort, and extends equipment lifespan. Oversized heat pumps are less efficient and more expensive to run.

4. Using the Calculator

Tips:

Enter your property's heat loss (from a heat loss calculation or SAP assessment)
Use the default COP of 3.5 (typical for UK air source heat pumps at 35°C flow temperature)
Adjust COP based on your specific heat pump's performance data if known

5. Frequently Asked Questions (FAQ)

Q1: How do I find my property's heat loss?
A: Through a professional heat loss assessment, SAP calculation, or using our Heat Loss Calculator tool.

Q2: What's a typical COP for UK heat pumps?
A: Most modern air source heat pumps have a COP between 3.0-4.0 under standard UK conditions.

Q3: Why does COP affect sizing?
A: Higher COP means the heat pump is more efficient, so it can meet your heating needs with less electrical input.

Q4: Should I add a buffer to the calculated size?
A: Generally no - heat pumps are most efficient when sized closely to the heat loss. Oversizing reduces efficiency.

Q5: Does this work for both air and ground source heat pumps?
A: Yes, but ground source heat pumps typically have higher COP (3.5-4.5) due to more stable heat source temperatures.