From DISCPACK1 to ROXSTAcube mini – 25 years of system refrigeration at Penny
Since 1996, when Penny launched DISCPACK1 as the first system refrigeration unit in food retail, much has changed. Today, the ROXSTAcube mini with natural CO₂ ensures sustainable cooling—two generations of tech by Penny, TEKO & Wurm.
A technically innovative pioneer – that’s what Penny has been from day one and continues to be today! From the very first standardized system refrigeration unit on the market to today’s environmentally friendly CO₂ solution – all developed hand in hand by Penny, TEKO, and Wurm.
1996: A new Penny store was being planned in Frankfurt-Unterliederbach. Back then, standard practice was to operate medium- and low-temperature refrigeration with separate rack systems. Since discounters had started using plug-in freezer islands, the only low-temperature cooling point left in a typical Penny store was the walk-in freezer.
One option on the table was to use condensing units – essentially a technological step back to the 1970s, with poor efficiency and high service risks.
It was against this backdrop that Rolf Schmidt – then responsible for refrigeration technology at Penny – approached us and asked for a refrigeration system that could handle everything in a closed, compact unit. The solution had to be highly efficient, use a modern refrigerant, and simplify handling for installers. That’s when the idea was born: integrating both medium-temperature cooling and the remaining low-temperature room into a standardized system.
No sooner said than done – after some development time, the prototype of our “DISCPACK1” was ready, using refrigerant R404A. Its rollout with the REWE Group was a complete success. The advantages of this technical innovation spoke for themselves, and so the first system solution in food retail was born – setting a milestone in the industry.
Thanks to its small footprint of just 1.5 m², the DISCPACK1 quickly went into series use at Penny. The very first unit in Unterliederbach ran almost trouble-free for 25 years. For TEKO, this project was a turning point: it marked the beginning of our focus on developing optimized refrigeration systems tailored to the needs of food retail – a specialization we still pursue today.
Compared with individual condensing units, the new system refrigeration solution offered significant benefits: 50% faster installation, a much lower refrigerant charge, and improved system hermeticity thanks to about 75% fewer soldered and screwed connections. The result was lower energy consumption and reduced space requirements since a separate machine room was no longer needed – making the DISCPACK1 the ideal rack system for a typical discount store.
Its successor, the “DISCPACK2,” even won the 1999 Environmental Award thanks to its low TEWI value when using R134a in combination with a low-temperature cascade and the further developed FRIGOTAKT process from Wurm.
From day one, Wurm has been a key development partner. For the very first DISCPACK1 system, the FRIGOTAKT control solution was created to coordinate refrigeration circuits with maximum efficiency—without adding unnecessary complexity.
This smart system balanced the refrigeration load perfectly, enabling precise coordination between individual units. By staggering the load phases, it achieved energy savings of up to 25%.
Today’s evolution of the system, FRIGOTAKTplus, harnesses the power of modern processors to deliver even greater advantages. These include continuous online planning of refrigeration circuits, adaptive performance profiles, and automatic setpoint determination based on integrated compressor characteristics.
FRIGOTAKTplus constantly recalculates the current load situation in real time. The system evaluates whether, for example, switching on a compressor or delaying the start of a refrigeration circuit will optimize overall performance—and ensures the entire cooling system runs at peak efficiency.
2019: The original Penny store in Unterliederbach—typical for a discounter at the time—was still integrated into a residential block. But 25 years after its opening, the store had grown outdated. Rather than renovating, Penny built a brand-new market just 500 meters away, designed to accommodate the latest technical and innovative standards.
Since the first installation of DISCPACK1 back in 1996, much has changed. Natural refrigerants have become a top priority for operators. In the new building, DISCPACK was therefore replaced with our series solution ROXSTAcube mini, running on the environmentally friendly refrigerant CO₂. From a design perspective, the system’s compact footprint has remained the same—still requiring no more space than a single pallet.
The original 455 m² store was equipped with 18.75 meters of refrigerated shelving powered by DISCPACK1. In the new store, that number has nearly doubled to meet rising demand for fresh, chilled products. Our ROXSTAcube mini now provides cooling for 30 meters of refrigerated shelving—26.25 meters for dairy and 3.75 meters for meat. In addition, one medium-temperature and two deep-freeze storage rooms were integrated into the new market for warehousing and the in-house bakery. Thanks to glazed refrigerator doors, energy consumption has remained almost unchanged despite the larger cooling capacity.
The system also recovers waste heat, which is used to heat the store during colder months—delivering further significant energy savings for the operator.
The new building also brings practical advantages. In the old location, the refrigeration system was tucked away in a cramped, hard-to-access basement beneath the residential block. With the ROXSTAcube mini, space-saving installation was essential. Thanks to its divisible frame, the unit could be split into two modules, placed side by side, and adapted to a height of just 1.80 meters (instead of the standard 2.10 meters stacked).
Another challenge was the in-store bakery, where dough is freshly baked every day. To save space, a combined storage room was developed—accessible both from the bakery, with its constantly running ovens, and from the supermarket side for stocking. This setup required a tailored cooling solution, which was achieved with a speed-controlled compressor. Since 2019, this solution has also been rolled out across all comparable Penny stores.
From an ecological standpoint, the Penny Group has been a true pioneer, equipping its store with forward-looking technology as early as 1996. This was driven both by the innovative spirit of Penny trailblazer Rolf Schmidt and by Penny’s foresight regarding the European F-gas regulation, which continues to reshape the market and drive the development of ever more sustainable technologies.
Today, CO₂ as a natural refrigerant is regarded as the ideal solution for achieving both high efficiency and environmental responsibility in food retail. In fact, the Penny Group became a nationwide leader in CO₂ refrigeration technologies in Germany—a pioneering spirit rarely seen.
By the way!
Since April 2019, the historic DISCPACK1 from the Penny store has been on display in the TEKO showroom in Altenstadt—probably one of the very last DISCPACK1 units still in existence.