Case studies

More Natural Refrigeration for the Brewing Process

Maxlrain Castle Brewery expands its Refrigeration and Production Capacity



TH. WITT Kältemaschinenfabrik GmbH



Cooling capacity:

150 kW

System start-up:




The private Maxlrain Castle Brewery in Bad Aibling, Upper Bavaria, has repeatedly been acclaimed as Germany's Best Brewery, and takes pride in having received the Federal Honorary Award for top rankings in the DLG Quality Tests nine years in succession. The product range offered by the brewery first officially mentioned in 1636 includes among others 15 beer specialities to suit every taste, from export beer, lager and wheat beer via "Märzen" beer through to craft beer specialities. In order to meet the constantly growing demand, Maxlrain was looking for a viable refrigeration solution to expand its production capacities. The existing NH3 / ethylene glycol refrigeration system was causing bottlenecks as the refrigeration capacity was no longer able to cope with the new production targets. Another challenge that came with the project was the requirement to continue using the existing system, despite the lack of space in the machine room for a second system or for a conventional extension of the ammonia system.



In view of the space constraints in the machine room, the new refrigeration system has been installed outside as a compact water chiller unit. The natural refrigerant R723 is used in the liquid chilling unit and combined with an ethylene glycol water blend in the secondary circuit. One special feature of the system: the selected reciprocating compressor works in combination with a high-pressure float regulator and the flooded high-efficiency evaporator for optimum adjustment to the varying outside temperatures. The air-cooled condenser with EC fans ensures optimum energy efficiency in part and full load. Thanks to refrigerant R723 with its very high volumetric refrigeration capacity, the system achieves a cooling capacity of 150 kW with a very small refrigerant charge of just 40 kg. Furthermore, it provides the viable solution required by the operator because R723 as a natural refrigerant is not affected by the statutory prohibitions in the framework of the European F-Gas Regulation.

Technical data:


Type of facility:




Refrigeration charge:

Refrigeration capacity:


40 kg

150 kW

Evaporating temperature:


Condensing temperature:

+40°C (max.), annual average: + 19°C

Outside temperature:

annual average: + 12°C


TH. WITT Kältemaschinenfabrik GmbH

Johannes Oellig

Lukasstraße 32

52070 Aachen, Germany