1. What is Heat Pump Sizing?

Heat pump sizing is the process of determining the appropriate capacity (in kW) of a heat pump system needed to effectively heat or cool a given space. Proper sizing is crucial for energy efficiency, comfort, and system longevity.

2. How Does the Calculator Work?

The calculator uses the basic heat pump sizing formula:

Where:

• \( \text{Area} \) — Floor area in square meters
• \( \text{Factor} \) — Heating/cooling factor (typically 50-100 W/m²)
• 1000 — Conversion from watts to kilowatts

Climate Adjustment: The calculator adjusts the base size based on Australia's climate zones:

• Zones 7-8 (colder): +20% capacity
• Zones 1-2 (warmer): -10% capacity
• Other zones: No adjustment

3. Importance of Correct Sizing

Details: An undersized heat pump will struggle to maintain comfortable temperatures, while an oversized unit will short-cycle, reducing efficiency and lifespan. Proper sizing ensures optimal performance and energy savings.

4. Using the Calculator

Tips:

• Measure your floor area accurately in square meters
• Typical factors: 50-80 W/m² for well-insulated homes, 80-100 W/m² for average, 100-150 W/m² for poorly insulated
• Select your climate zone based on Australia's 8 climate zones

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between heating and cooling capacity?
A: Heat pumps often have different ratings for heating and cooling. This calculator provides a general capacity estimate - consult manufacturer specs for specific models.

Q2: How does insulation affect sizing?
A: Better insulation reduces the required capacity. For well-insulated homes, use the lower end of the factor range (50-80 W/m²).

Q3: Should I round up the calculated size?
A: It's generally better to choose the nearest available size rather than rounding up, unless you have specific needs for rapid heating/cooling.

Q4: What about ceiling height?
A: Standard calculations assume 2.4m ceilings. For higher ceilings, increase the area proportionally (e.g., for 3m ceilings, multiply area by 1.25).

Q5: Does this work for ducted systems?
A: This provides a whole-house estimate. Ducted systems require professional calculation accounting for duct losses and zoning.