For the central kitchen and restaurant of a Dutch university hospital, we supplied a complete refrigeration system based on a transcritical CO₂ system with heat recovery. What made this project particularly challenging was that the kitchen and serving restaurant had to remain operational throughout the entire construction phase. This required tight planning, smart phasing, and close coordination with the user.
New machine room and piping routes in a running environment
To be able to realize the installation, a new location within the existing building was first selected that could be set up as a machine room. A suitable outdoor location was also determined for the placement of the gas coolers. After determining the optimal piping routes, the installation of the piping and the required cabling began. Part of the machine room was constructed on-site. To keep the nuisance for the hospital to a minimum, critical piping sections were installed at night.
Dual air coolers to ensure continuity
To continue guaranteeing the existing cooling function, temporary dual air coolers were placed in the rooms to be cooled. Once these new coolers functioned without problems, the old installation parts were dismantled in phases. Subsequently, the remaining rooms were equipped with new air coolers one by one, each time only after the old cooler had been removed. As a result, the downtime per room was kept to a minimum and the hospital's kitchen function was not compromised for a single moment.
A versatile installation for various temperature requirements
The delivered refrigeration system consists of a transcritical CO₂ compressor unit with heat recovery. Due to the variation in consumers and temperature levels, a combination of three systems has been chosen:
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CO₂ pump system, which powers 11 air coolers
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Direct expansion of CO₂, for 6 air coolers
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thermosyphon section, connected to the knockout drum, for cooling a refrigerant that subsequently supplies cold to 7 air coolers
All air coolers are equipped with hot gas defrost.
Energy efficiency and heat recovery
The heat recovery of the CO₂ system is connected to a central district heating network, allowing waste heat to be used productively elsewhere in the hospital. The gas cooler is equipped with adiabatic cooling, which achieves significant energy savings on warm days.
Control and monitoring
The complete installation is controlled by an extensive operating system with a visual interface. This ensures both local manageability and remote control, allowing the hospital to continue monitoring the installation efficiently and safely.
