One of the most overlooked—but critical—factors in optimizing a heat pump’s performance is the flow temperature. If you’re aiming for higher efficiency, lower energy bills, and longer unit lifespan, this is the number to pay attention to. In today’s #FridayTech, we break down what flow temperature is, why it matters, and how to adjust it for peak performance.
What is Heat Pump Flow Temperature?
The flow temperature refers to the temperature of the water leaving the heat pump and entering your heating distribution system—radiators, underfloor heating, or fan coils. Typical flow temperatures range from 30°C to 55°C depending on the type of emitters in your system.
Why Lower Flow Temperatures Mean Higher Efficiency
Heat pumps work best when they move heat rather than generate it—the lower the target temperature, the less work they have to do. This is directly linked to the Coefficient of Performance (COP):
- At 35°C flow, the COP can be over 4.5
- At 55°C flow, it can drop below 3.0
That’s a 35–40% efficiency difference, just by adjusting the temperature.
When and How to Lower the Flow Temperature
- Underfloor Heating Systems: These are ideal for heat pumps because they can operate efficiently with flow temperatures between 30–40°C. If you’re using a Tongyi R290 heat pump, you can fine-tune this setting via the control panel or the IoT app interface.
- Oversized Radiators or Low-Temperature Radiators: These allow you to drop flow temperatures to 45–50°C while still maintaining comfort.
- Weather Compensation Curve: Modern Tongyi units support automatic adjustment of flow temperature depending on outdoor temperature. This dynamic response—known as weather compensation—is one of the smartest ways to keep efficiency high without manual intervention.
Installation Tip: Get Your Installer Involved
Reducing flow temperature isn’t just about changing a number—it’s about matching the system design. Speak with your installer or heating engineer to:
- Rebalance emitters if needed
- Enable or fine-tune the heating curve
- Verify return temperatures and delta T values for optimal compressor operation
The Takeaway
If your heat pump is operating at unnecessarily high flow temperatures, you’re leaving efficiency on the table. By understanding and adjusting your heat pump flow temperature, you can unlock up to 40% energy savings and extend your unit’s life—all while keeping your home just as warm.
Need support adjusting your flow temperature settings? Reach out to us or check your Tongyi smart controller manual for step-by-step guidance.
