Two testing units have been installed

1. Indoor
Allows testing independently of the solar radiation and external temperatures.
The sun is simulated using halide daylight spotlights

2. Outdoor
Used to verify the test results under real solar radiation

HyWin Indoor Test

  • Aluminum frame with isolated side walls

  • Dimensions: W=0.5 m H=1.1 m and D=0.3 m

  • Textile sun shield in the cavity

  • Outside glass: tripple layer, u-value 0.5 W/m²K

  • Internal glass: safety glass, u-value 5 W/m²K

  • Cooling unit at bottom with 5 small fans

  • Sun simulation: 8 metal halide lamps,  total  power of 2'400W

  • Cooling water temperature control   

  • Data acquisition with computer controlled datalogger

    • 8 temperature sensors inside the cavity

    • 2 temperature sensors outside the cavity

    • 2 temperature sensor for cooling water in and out

    • 2 humidity sensors inside and outside the cavity

    • 1 precision flow meter for  cooling water  

HyWin Outdoor Test

  • Same basic design as indoor

  • Mounted on a frame with wheels to align with sun direction

  • Cooling and heating optimized for outdoor application

  • As an option, the energy required to operate the fans can be drawn from a solar cell mounted above the window

  • Measurement devices and electronics protected for outdoor operations

HyWin cools down an overheated window

In this indoor experiment a CCF (Closed Cavity Facade) was simulated first. Then the  cooling was switched on (temperature of cooling water 18°C) 




0 to 6'070 sec

Heating with 8 haline spotlights, no cooling. The temperature in the window keeps rising as the energy from the heating accumulates. The six curves represent the readings from the temperature sensors on the "sunny" side (upper 3 lines) and on the "room" side (lower 3 lines)




6'070  to 10'000 sec

Cooling and fans are switched on. The heat removal kicks in instantly. HyWin reacts within seconds and after 10-15 minutes the temperature is stabilized between 20 and 23 °C and the the heat extraction at constant 200 W. 




HyWin behaviour on a hot, sunny day

Here the HyWin was operated outdoor for 10 hours. The cooling water temperature was kept at around 18°C.

The outside temperature increased up to 30°C and dropped after the sunset to 24°C.

The relevant average temperature in the  cavity at the indoor side was kept at 22°C and dropped after the sunset to about 20°C.






During the day the power removed from the heat exchanger increased from 150 W at the beginning  up to 200 W at 18'000 s (high noon) to 50 W  in the evening. The drop around 20'000 s was due to clouds, which covered the sun for few minutes. ( 

HyWin measurement Hot day
HyWinPower Sunny day