The History of Rox

Since 2006, Rox has been part of the Rosenberg Group and continues its business under the name “Rox Klimatechnik GmbH.” Together with the Rosenberg Group, many new opportunities have opened up. Today, Rox Klimatechnik GmbH covers a broad spectrum of climate technology and stands out thanks to its extremely flexible construction approach and extensive experience. Whether it’s central air handling units, cabinet units, rooftop units, hygienic compact units for operating room air conditioning, ATEX explosion-proof units, or dehumidification systems – there is a suitable solution for every application, with air volumes ranging from 1,000 m³/h to 100,000 m³/h. This includes units with integrated or external control cabinets, refrigeration systems, heat pumps, and all types of heat recovery systems – from crossflow and counterflow plate heat exchangers to rotary heat exchangers or simple to highly efficient KV systems.

In 1996, “Rox Lufttechnische Gerätebau GmbH” became the employee-owned company “ROX Lufttechnik GmbH,” continuing its dedicated, customer-focused philosophy that the unit, its application, and the system solution form an integrated whole.

Significant innovations in air conditioning technology came in 1973 with the introduction of the first ROX hygienic units and the development of unit silencers. During the 1970s, an intensive discussion among experts about the limits and acceptance of turbulent mixing flow in rooms led to the rediscovery of displacement flow or source ventilation with laminar or low-turbulence airflow. ROX operating room supply air ceilings for laminar displacement flow with extremely low contamination levels were developed in response to these new challenges. Similarly, the ROX HYD series units, with properties always optimized for individual requirements, such as housing dimensions and built-in components, became increasingly in demand and were widely used and continuously refined.

In 1965, Rox established its first climate technology laboratory. With its excellent engineers, the company enabled further research into the fundamentals of heat engineering, acoustics, and room air flow technology. A method for determining the noise and sound-absorbing properties of system components was published, as well as a calculation method for the pressure balancing of air distribution ducts for induction systems. These scientific findings formed the basis for the design of modern equipment and its application in system construction. As a result, standardized central air handling units of the N series were developed with capacities up to 80,000 m³/h and 3,000 Pa, induction units with valve and damper control, two-channel mixing units (MIXAIR), and the RADIAIR unit received a modern design.

The ROX brand experienced rapid growth. ROX produced and marketed its patented equipment with great success, including the first induction unit developed in Germany, RADIAIR, and the so-called ROX swirl diffuser for draught-free distribution of cold air from the ceiling. As early as the 1950s, ROX units of all types were in use not only in Germany but also in Belgium, Italy, the Netherlands, Norway, Austria, Switzerland, Spain, and Turkey, supported by ROX international representatives. In 1963, the production facility was relocated to Weitefeld, where it remains to this day.

In 1953, a larger office building had to be occupied, which was then further expanded. ROX Lufttechnischer Gerätebau GmbH was on a steady path of growth. Between its founding and its 10th anniversary, order intake increased tenfold, and the company grew to 42 employees. The product range was expanded, and ROX units were produced in many variations: cabinet units, niche units, box units, console units, residential units, and full air-conditioning systems initially handling air volumes of up to approximately 20,000 m³/h. With air velocities of 0.7 to 2.0 m/s, noise levels were low and energy consumption was modest. While today energy consumption for air handling units is limited by standards and regulations, this serves as an interesting reminder of the evolution of technology, business, and society over the years.

As order volumes and staff numbers grew steadily, production was soon relocated in 1950 to the Westerwald, into the site of the former ‘Auf der Bindweide’ mine.

After its founding in 1949, the Federal Republic of Germany was in the process of reconstruction following World War II. Mines, steelworks, factories, department stores, administrative buildings, and hospitals were being built and required modern technology.

The planning engineer, inventor, and founder of “ROX Lufttechnische Gerätebau GmbH” integrated all the necessary air-handling components—such as fan, heat exchanger, damper, and filter—into a single housing. This new idea led to the creation of the first ROX unit and thus the first air-conditioning unit in Germany.

It was a cabinet unit, built in a small workshop in Cologne and installed in a modern office of the company Zanders in Bergisch Gladbach. Its low noise level, easy access to all components for maintenance, and high-quality workmanship made the unit a long-lasting capital asset.