The compact chiller will deliver a cooling capacity up to 160 kW in a very small space. The chillers are operated with two redundant refrigerant circuits to increase operational reliability. Both circuits are controlled on the basis of the required cooling capacity, so that the respective circuit is activated with maximum efficiency when minimal cooling is needed. The WPAmini is equipped with maximum size aluminium microchannel condensers and four scroll compressors, which are activated and deactivated (25, 50, 75, 100 %) in stages, in line with the current heat load. The compressor operating time can be reduced to a minimum using the optional free cooling facility, which will considerably reduce power consumption, and operating costs. Three operating modes are available in total: DX mode, free cooling mode and mixed mode. In mixed mode, cooling capacity is generated by means of simultaneous free cooling and compressor cooling. This means that significant energy savings can be achieved even at moderate outdoor temperatures.
In noise critical applications, a ‘quiet’ version is available that has extra acoustic insulation. Here, the compressors are enclosed in a special sound-insulated housing, which lowers the volume to conversation level. The chillers can also be fitted with optional fan diffusers, which will improve the air conduction and further reduces the noise level, as well as electricity consumption.
Thanks to the technology, this latest innovation from STULZ can also run in extreme local climates. Its extensive operating limits range from -40 to +50°C, depending on the model. The generously designed switch gear cabinet ensures there is space for any additional electrical equipment. This is a real benefit as there is no need for extra switch gear cabinets or extensions. Looking to the future, the WPAmini chillers already meet stage 2018 of the EU legislation - Ecodesign of the Energy-related Products Directive (ErP) which comes into effect September 2018.