Setting down the reversible chillers for the industrial park “The Valley”
Many may still remember: When driving past the factory A1, motorists often met with a waft of spices. The former premises of the legendary, world-famous company Maggi now houses 138 businesses. The historic industrial park “The Valley” will soon be sustainably heated and cooled using the ambient air. Boasting a total heating capacity of 2.2 MW and 2.7 MW cooling capacity, the four reversible chillers were installed in June 2023 and will supply the park with the requisite heating and cooling from October 2023. During its 30-year service life, the new energy system will save more than 44,000 tons of CO2, equivalent to the capturing and storing power of around 120,000 trees.
The four air/water heat pumps output between 170 and 550 kW of power each and are equipped with four output-regulated reciprocating compressors. The cooling circuits are filled with the natural refrigerant R-290 (propane). CTA is playing an important role in this project: Not only is it responsible for regulating the heat pumps’ cooling circuits, it also provides a control system for the entire plant. CTA thus controls all heat pumps, recoolers, and hydraulic components to ensure the correct heating and cooling output for this historic factory site.
The chillers’ cooling circuits are filled with the natural and sustainable refrigerant R-290. It has an extremely low global warming potential (GWP) value of three. However, propane does present one challenge: It is flammable. Cooling systems using propane as a refrigerant must therefore meet higher safety requirements. This challenge was met by installing and wiring the requisite safety features in the factory and by mounting, insulating and wiring most of the hydraulic components in the chiller housing prior to delivery.
The heat pumps on site
Four reversible chillers
Total capacity: 2.2 MW (heating) and 2.7 MW (cooling)
Refrigerant: R-290 (propane)
Installing the four reversible chillers on the roof enabled expensive building space to be rented out and thus be put to better use. However, the available roof size is limited. Boundaries and maximum component sizes were known from the design phase. Accurately designing and engineering the system components was the key to success right from the start.
Experiences for future projects
Energy provider: EKZ, Zurich
Site developers and property owners: Mettler2Invest, St. Gallen
Planning/design: EKZ and CTA
Installation: pietrobon hvac gmbh (HVAC) / ETAVIS AG (el. inst.)
Heat pumps and system supplier: CTA AG, Münsingen