Polish project demonstrates effectiveness of Rehau ground-to-air heat exchanger
The performance of the Rehau Awadukt system at a 1000 m2 Tesco store in Poland has demonstrated a performance about 25% higher than predicted by Rehau GAHE software.
The independent validation comprised a year of research and monitoring carried out in collaboration with Tesco and the institute for heating technology at the Technical University of Posen.
The Awadukt Thermo ground-to-air heat exchanger can achieve a COP of up to 50 on commercial projects. When used with an energy-recovery system, HVCA equipment can be significantly downsized.
The Awadukt system has an heating output of about 26 MWh a year, more than half the store’s annual requirement of 46.3 MWh — making it possible to downsize heating plant from 48 kW to 28 kW and cooling plant from 38 to 23 kW.
The installation has an air flow of 2700 m3/h and uses a 35 m-long Tichelmann grid system with 20 runs of DN200 pipes for heat transfer and DN500 header pipes. The grid is directly under the store, which improves cooling performance.
With external air at -7°C, exit temperatures form the AWADUKT Thermo pipework reached 13°C, only 6 K below the typical internal air temperature of 19°C.
On the hottest summer day, an external temperature of 35°C was reduced to just 18°C.
