Natural refrigeration for delectable cheese

Image: Getty / Animaflora

Quality and naturalness form the DNA of Austrian gourmet cheesemaker Woerle, which is why the company opted for three BITZER Ammonia Compressor Packs when building the new refrigeration system

Mountains, lakes, idyllic nature – there’s much to discover in the State of Salzburg. One of the region’s highlights is Lake Wallersee, a popular holiday destination some 18 kilometres north-east of Salzburg. Here, gourmet cheesemaker Woerle, in its fifth generation of family management, manufactures the finest speciality cheeses, which customers had delivered to Rome and Prague 120 years ago. Ever since, quality has been the top priority for the long-standing company, which now produces more than 28,000 tonnes of cheese each year, using exclusively milk from cows that eat fresh grass or hay.

Fine cheese dairy Woerle produces various types of cheese
As with cheese, Woerle was also right about the refrigerant: it had to be natural

Traditionally natural

Woerle applies the same high standards to its systems as it does to the components of its products, commissioning the Austrian system supplier Herzog Kälte-Klima to develop a new refrigeration system for its production. For Woerle, it has to be natural, whether it’s cheese or refrigerant.

‘We at Herzog have been working with BITZER products for 40 years. Even our customer Woerle was already familiar with BITZER. It was ultimately the outstanding value for money that made the company opt for BITZER ACPs.’


Herbert Khier
Project Manager at Herzog Kälte-Klima

Efficiency and sustainability: BITZER Ammonia Compressor Packs

The contractor preferred the use of the natural refrigerant ammonia (GWP 0) and immediately had a high-quality solution: three BITZER Ammonia Compressor Packs (ACPs). For this special application, BITZER equipped each of the ACPs with one or two OSKA95 screw compressors. Each unit can also be expanded with another compressor. Both of the double-pole high-speed motors in each ACP boast a capacity of 315 kW, a maximum speed of 4,200 rpm and frequency inverter, ensuring maximum operating efficiency.

BITZER ammonia compressor pack
Each of the three ACPs contains OSKA95 screw compressors and a three-stage horizontal OAHC oil separator

Environmentally friendly and efficient – ammonia

The three units provide cooling capacity for the cold stores, the ventilation systems and the entire production process at Lake Wallersee, maintaining the temperature of the liquid coolant at –12°C and the ice water at +2°C. Ammonia is ideal for large systems in the food industry, as it combines high energy efficiency and outstanding thermodynamic characteristics with environmental compatibility. There’s also the fact that it doesn’t have any global warming or ozone depletion potential (GWP and ODP 0). Those are perfect conditions for many applications.

‘A great advantage of our Ammonia Compressor Packs for customers is that they receive a fully assembled and ready-to-use compressor unit from BITZER that can be installed quickly and easily. And they’re already familiar with the high efficiency and reliability from our components.’


Rainer Große-Kracht
Member of the Management Board and Chief Technology Officer at BITZER

Partners for 40 years: Herzog and BITZER

‘We at Herzog have been working with BITZER products for 40 years. Even our customer Woerle was already familiar with BITZER. It was ultimately the outstanding value for money that made the company opt for BITZER ACPs. And the “Made in Germany” label also carries a lot of weight here in Austria,’ explains Herbert Khier, Project Manager at Herzog Kälte-Klima.

Lorry with BITZER ammonia compressor packs in the background and installers towards the front
It’s all a question of planning: Herzog Kälte-Klima transported the BITZER ACPs to the right place with a huge team

Huge tasks require good planning

Herzog Kälte-Klima delivered the three units at the end of 2018. And that was no easy task, as each ACP weighs in up to 7 tonnes and is impressive in size, measuring 2.2 metres in length, 2.7 metres in width and 2.3 metres in height. But that was no problem for the system professionals of the company based in Styria – after all, good planning is everything. A 220-tonne crane lifted the ACPs to a height of around 20 metres and delivered them to the installation room, which required a crane operator, two banksmen and three installers.

Teamwork with TÜV seal

With the ACPs delivered to the installation room, it was time for the vibration-reducing machine base to do its part, with five installers from Herzog Kälte-Klima managing this second transport step. Once the ACPs were securely in place, the installation team went into action: a welder, two pipe fitters and an electrician prepared the units for operation. TÜV monitored installation of the pipes with process inspection, design examination in accordance with the Pressure Equipment Directive, X-ray testing of weld seams, and a pressure test. Once everything had been carefully assessed, the specialists filled the systems with ammonia refrigerant, which was then followed by electrical mounting, approval of the safety technology, and function control provide by TÜV.

Efficient BITZER OS.A95 ammonia screw compressors: flexible and eco-friendly

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BITZER Ammonia Compressor Packs achieve a cooling capacity of up to 3 MW (–10/35°C) and consist of OSKA95 screw compressors and a three-stage horizontal OAHC oil separator. All ACPs have a high-pressure controller as standard. All the components are developed and manufactured by BITZER and are optimally compatible with each other. Parallel connection of multiple compressors and intelligent capacity control enable safe and efficient operation. Another benefit of ACPs is the servicing-friendly construction, which means that all the components are easy to reach. BITZER develops and manufactures its Ammonia Compressor Packs in Hailfingen, some 50 kilometres south of Stuttgart.