How to Select EN 14511 Test Conditions to Maximise Commercial HPWH Modelling Outcomes

For VEU Activity 44 and ESS IHEAB, EN 14511 testing forms the foundation of heat pump performance modelling.

While EN 14511 is a European standard, in the VEU and ESS schemes it is used for a different purpose: to construct a heat pump performance map that feeds into annual AS/NZS 4234 simulation models. This performance map defines how the heat pump performs — thermal capacity, input power, and COP — across combinations of air temperature (dry bulb/wet bulb) and water inlet temperature.

Selection of EN 14511 test conditions is not simple. Refrigerant choice, control logic, and thermal storage configurations all impact the range of test conditions chosen. Selecting appropriate test conditions is therefore a key step in ensuring accurate and compliant modelling results to maximise certificate outcomes.

Regulator Minimum Requirements

Scheme administrators (ESC, IPART) allow some flexibility in the selection of test conditions to suit different products. The minimum requirements are:

Water temperatures: maximum inlet temperature during operation (e.g. 60 °C)
Air temperatures (dry bulb/wet bulb): 2 °C/1 °C, 7 °C/6 °C, 12 °C/11 °C, or 19 °C/15 °C

The maximum inlet temperature is the highest inlet water temperature expected during normal operation. Two examples:

R-290 heat pump; tank set point 75 °C; temperature rise (ΔT) 5K — maximum inlet temperature = 70 °C
CO₂ heat pump; outlet 90 °C; compressor turns off when inlet temperature exceeds 50 °C — maximum inlet temperature = 50 °C

Instead of a “low temperature operation penalty”, results are linearly extrapolated down to dry bulb -5 °C — it is not necessary to test at -5 °C.

Additional Testing to Improve Modelling Outcomes

Inlet Water Temperatures

It is strongly recommended to include additional inlet water temperatures to capture maximum performance data:

Add minimum inlet water temperature (~10 °C) to showcase high capacity and COP at low water temperature
Add an intermediate inlet water temperature between minimum and maximum to capture the shape of the performance curve — units tend to spend more operation time at higher temperatures, so bias towards the higher temperature range (e.g. 50 °C)

Air Temperatures

It is strongly recommended to add a higher dry bulb point (30–38 °C) to show higher performance at higher air temperatures. System capacity and COP tends to be higher in hotter ambient conditions. While not mandatory, this additional test point provides significant improvement on certificate outcomes.

Baseline Recommendations

Baseline EN 14511 testing recommendation for R-290 systems:

Water temperature (inlet): 10 °C, 50 °C, 70 °C
Air temperature (dry bulb/wet bulb): 2 °C/1 °C, 7 °C/6 °C, 19 °C/15 °C, 38 °C/25 °C

Baseline EN 14511 testing recommendation for CO₂ systems:

Water temperature (inlet): 10 °C, 30 °C, 50 °C
Air temperature (dry bulb/wet bulb): 2 °C/1 °C, 7 °C/6 °C, 19 °C/15 °C, 38 °C/25 °C

Summary

To maximise certificates from modelling, start with accurate performance mapping, which leads to more accurate and compliant simulations, and thus optimum certificate yield. Smart testing means targeting data resolution where it matters most.

How EnergyAE Can Help

The precise choice of test conditions depends on your specific heat pump system. EnergyAE can assist with:

Reviewing your system and controls to refine test condition selection
Analysing in-house testing, modelling, and optimisation
Arranging third-party NATA-accredited testing
Final AS/NZS 4234 modelling
VEU (ESC) and ESS (IPART) commercial HPWH scheme applications

Get in touch with EnergyAE to discuss your project.