Heat Pump Balance Point Calculator
Determine the temperature where a heat pump alone meets the building heating load, factoring capacity degradation and internal gains.
For HVAC sizing studies; verify with manufacturer performance data and local codes before sealing designs.
Examples
- 18.5 kW heat loss at -12 °C, indoor 21 °C, 16 kW capacity, 0.18 kW/°C slope, 1.2 kW gains ⇒ balance point -2.77 °C (26.99 °F)
- 12 kW heat loss at -9 °C, indoor 20 °C, 13.5 kW capacity, default slope, no gains ⇒ balance point 1.94 °C (35.49 °F)
FAQ
What if the balance point is above my design outdoor temperature?
If the balance point sits above the design outdoor temperature, the heat pump cannot meet peak load alone. Plan supplemental heat or increase equipment capacity.
How do I estimate the capacity slope?
Use manufacturer performance tables that list capacity at two or more outdoor temperatures. Divide the change in capacity by the change in outdoor temperature to derive kW per °C.
Should internal gains always be included?
Include steady internal gains such as lighting, servers, or process heat that persist during peak heating hours. Intermittent gains should be excluded or modelled separately.
Can I work in Fahrenheit?
Yes. Convert your design temperatures to Celsius before entry. The calculator returns both Celsius and Fahrenheit for easy cross-checking.
Additional Information
- Balance point occurs where building heat loss equals available heat pump capacity.
- Capacity slope defaults to 0.18 kW per °C drop from 17 °C when manufacturer data are unavailable.
- Outputs are rounded to two decimal places and include both Celsius and Fahrenheit.