In 1998, the Wuppertal Swimming Center was equipped with eight HANSA HKG-WPE dehumidification units. These units were already equipped with heat recovery system which was highly efficient at the time (WPE-16: 73% in full load operation at 15,800 m³/h), consisting of two plate heat exchangers. Of course, the fans also complied with the energy standard at the time, which is required due to the energy-intensive and thus cost-intensive utilization profile of a dehumidifier for indoor swimming pools.

Six units were used for treating the highly polluted indoor swimming pool air. After approximately 20 years of operation, the consequences of the humid, chlorine-contaminated swimming pool air in the exhaust air line became apparent. Despite high manufacturing and material standards, this could not be completely avoided. Some housing elements and air dampers, the fans and some plate heat exchangers were affected.

Measures

Since the devices were still generally in good working order after two decades, the devices were refurbished rather than replaced. In just five weeks, all six units were brought up to a very good, up-to-date standard in a minimum of working hours. The recovery rate of the plate heat exchangers had received inevitable and irreversible damage and the polluted exhaust air had caused the fins to deteriorate. Replacing these in addition to the exhaust and supply air fans particularly led to a significant increase in the efficiency of the units.

The new fans have plastic impellers and meet current requirements. With a power consumption of 6.35 kW compared to 6.58 kW of the existing fans (WPE-16), 460 watts per unit could be saved thanks to this measure alone.

Conclusion

Sustainable quality standards when manufacturing air handling units do not stand in the way of cost reduction and ecological responsibility; on the contrary, they are an opportunity to modernize components that are essential for energy consumption while making the measure highly economically attractive. Fortunately for our customers, general refurbishments with a view to reducing consumption and operating costs are in fact a growing field of activity in our company.