1. What is Heat Pump Sizing?

Heat pump sizing determines the appropriate capacity (in BTUs) needed to efficiently heat or cool a space based on room size, insulation quality, and climate factors. Proper sizing is crucial for energy efficiency and comfort in New Zealand homes.

2. How Does the Calculator Work?

The calculator uses the standard sizing formula:

Where:

• \( Area \) — Room area in square feet
• \( Factor \) — BTU per square foot (typically 25-30 for NZ conditions)
• \( Insulation\ Adjustment \) — Multiplier based on insulation quality (0.8 for poor, 1.0 for average, 1.2 for excellent)

Explanation: The calculation accounts for both the physical size of the space and the thermal properties of the building.

3. Importance of Proper Sizing

Details: Correct heat pump sizing ensures optimal performance, energy efficiency, and longevity. Oversized units short-cycle, while undersized units struggle to maintain temperature.

4. Using the Calculator

Tips: Measure your room dimensions accurately. For open-plan areas, include connected spaces. Choose the insulation factor that best matches your home's thermal performance.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical BTU factor for NZ homes?
A: Most NZ homes use 25-30 BTU/sq ft, depending on climate zone. Warmer regions can use lower values (20-25), cooler areas may need higher (30-35).

Q2: How do I assess my insulation?
A: Newer homes with double glazing and ceiling/wall insulation use 1.1-1.2. Older homes without insulation should use 0.8-0.9.

Q3: Should I round up the BTU result?
A: Heat pumps come in standard sizes. Choose the next available size if your calculation falls between standard capacities.

Q4: Does ceiling height matter?
A: Standard calculations assume 2.4m ceilings. For higher ceilings, increase the area proportionally (e.g., 3m ceilings = area × 1.25).

Q5: What about rooms with lots of windows?
A: Add 10-20% to your BTU requirement for north-facing rooms with large windows, or subtract 10% for well-shaded rooms.