The University Hospital Großhadern is home to a specialized company that produces a unique, radioactively charged drug for cancer diagnostics in human medicine. Our task was to design and install a state-of-the-art refrigeration system that reliably cools the sensitive equipment and materials with maximum security of supply.

Project execution and challenges

For this demanding and critical project, our highly qualified team installed a dual redundant refrigeration system to guarantee maximum availability and reliability. However, the implementation was associated with considerable challenges:

• Limited space: Due to the limited space on the construction site, it was impossible to install the system in its original state. We had to dismantle the entire refrigeration system on site, transport the individual parts to the basement and the technical centers and reassemble them there. This complex process required precise planning, coordination and expert execution to ensure that all components were correctly installed and functional.

• Time-critical installation: Due to the high demands on the operational readiness of the medical devices and the strict deadlines, a prompt yet careful installation was necessary. Our team was able to master this challenge thanks to efficient work processes and close cooperation with the other trades involved.

Technical details and operation

The refrigeration system was installed in 2013 and uses the refrigerant R410A. At that time, natural refrigerants were still very rare, and the limited space available only allowed for compact and capacity-controlled scroll compressors.
The efficiency and cost-effectiveness requirements necessitated the use of this classic refrigerant. The decision to use R410A enabled us to raise the heat recovery of the system to over 65°C.

Since its commissioning, the refrigeration system has been running continuously and trouble-free. Regular maintenance measures contribute significantly to the longevity and reliability of the system:

• Oil change: A comprehensive oil change is carried out every two years to ensure the smooth operation of the compressors and other mechanical components.
• Filter dryer replacement: The filter dryers are replaced once a year to maximize the safe functioning of the cooling system and prevent contamination.

It is remarkable that neither compressors nor switchgear or sensors have had to be replaced so far, which underlines the high quality of our installation and the perfect planning of the system.

Redundancy and security

The refrigeration system has a classic design and consists of two redundant refrigeration systems with two redundant cold water systems that load a buffer storage battery with 10,000 liters of cold water. This storage battery provides a small additional fault reserve to compensate for any failures. Further safety measures include:

• Fault reserve connection: There is a connection for the Großhadern University Hospital’s fault reserve, which can be activated if one or both systems should fail. This mechanism guarantees three-stage maximum availability.

This three-stage redundancy is crucial, as the cyclotron must be shut down continuously and in a defined manner in order to guarantee the safety functions of the entire system and avoid potential hazards.

Efficiency and sustainability

Our refrigeration system not only impresses with its reliability, but also with its efficiency and sustainability. Each chiller in our system provides 330 kW of cooling, which fully covers the company’s high cooling requirements. The facility also offers:

• 80 kW heat output: These are used as a heat recovery system for heating. This is particularly important as the ventilation units also operate laboratories and therefore require cooling, dehumidification and reheating to ensure the air conditioning of the relevant rooms.

• Energy savings and sustainability: The efficient use of waste heat not only contributes to energy savings, but also supports the sustainability of the entire system. These measures demonstrate our commitment to environmentally friendly and sustainable solutions.

Conclusion

Our expertise in the planning, installation and maintenance of complex refrigeration systems ensures that highly sensitive medical facilities such as the University Hospital Großhadern are always cooled reliably and efficiently. With our technology, we ensure that vital medical processes can continue uninterrupted. Through precise planning and careful implementation, we offer maximum security of supply for the demanding medical applications of this specialized company.