60 years of industry-related cutting-edge research (1964 - 2024)

Since its foundation in January 1964, the ILK Dresden has stood for cutting-edge research.

Top-level research is comparable to top-level sport. An inspiration alone does not make a resilient product. Daily dedicated work with setbacks and doubts are the rule rather than the exception. Cutting-edge research also means constantly reinventing yourself, questioning the tried and tested and networking people with each other, their talents and their abilities in order to achieve the best results.

In 2024, the Institut für Luft- und Kältetechnik gGmbH will celebrate its 60th anniversary. Since our foundation in 1964, we have been a close partner to industry, science and society. Our work is geared towards the practical needs of our customers. On the one hand, we make a concrete contribution to economic value creation. On the other hand, we are committed to protecting our planet and people by looking for sustainable solutions to preserve our environment. As early as 1964, it was laid down in the statutes that the ILK Dresden has the task of developing new products with a long service life and low material and energy consumption. These are all issues to which we still feel committed today.

Minister President Michael Kretschmer emphasises: "Germany's most important resource sits between our ears."

The reason for the meeting was a public information event on the topic of "KETEC" in Reichenbach im Vogtland, which focused on the planned Federal Competence Centre for Refrigeration and Air Conditioning Technology.

At the so-called "Market of Innovations", all of the centres of excellence for refrigeration and air conditioning technology in the Vogtland region as well as the KETEC-1 project participants, the ILK Dresden, the ISE Freiburg and the TU Chemnitz, presented themselves.

Reichenbach in Vogtland is historically, but above all looking to the future, a predestined location for training, studies, industry and research in the field of refrigeration and air conditioning technology. The company Thermofin GmbH alone, which provided the idea for the competence centre, employs more than 500 people in the region. In addition, the BSZ and the SKF Saxon Refrigeration College as well as the Saxon Guild of Refrigeration and Air Conditioning Technology are already based here.

The KETEC project builds on this potential and will strengthen the location as well as the transfer of knowledge between research and applied refrigeration and air conditioning technology.

The ILK Dresden is involved in 3 of 13 forward-looking sub-projects:

• SP5: Generation and storage of liquid ice/ice slurry as a refrigerant using the vacuum ice process, development and testing of a system in the low power range (80 kW)
• SP7: Development and testing of components and operating modes for systems with the refrigerant ammonia, in particular for deep-freezing processes down to -30 °C
• SP9: Generation and storage of ice slurry as a refrigerant using an innovative injection process and development and testing of a demonstrator system with feed-in to cold water systems

Visitors to the Dresden Long Night of Science were magically drawn to the ILK Dresden this year, as our scientists created a special highlight - real snow!

The cool white in our research projects on the topic of vacuum ice storage is actually much more liquid - a so-called ice slurry.

This is a process in which liquid ice is produced in a direct evaporation process using a water vapour turbo compressor specially developed by the ILK Dresden. The areas of application for the process are extremely broad. For example, "cold/liquid ice" can be used to store renewable energy, e.g. from wind turbines, in a highly efficient manner. Server stations and data centres could also be cooled in an environmentally friendly and effective way. There are also many other examples of applications.

The youngest visitors to the Long Night of Science were satisfied for the time being with the surprising cooling effect of throwing snowballs.

The prestigious prize is awarded every two years to recognize an outstanding partnership project that improves the environment through novel and creative approaches.

The "ColdHubs" project provides energy-efficient, solar-powered walk-in cold rooms to close Nigeria's cold chain gaps and reduce post-harvest losses for smallholder farmers in rural Nigeria. The ILK Dresden led the technical research and prototype design, while the Smallholders Foundation contributed its regional expertise, market access and technical know-how to the collaboration. Dr. Goldberg accepted the award at Harvard.

On August 18, 2022, the time has come. The foundation of the first start-up of the ILK Dresden is notarized and entered in the commercial register.

Christoph Steffan, previously a research assistant in Dr. Safarik's team, ventures into self-employment with the institute's liquid ice technology. The decision to phase out coal in his home region of Upper Lusatia was a sign for him. The technical developments at the ILK Dresden are almost ready for the market.

The infrastructure is already in place, as are existing district heating networks, an inquisitive workforce and industrial manufacturing companies. The first excursions to Zittau took place in November 2022. Under real conditions, a short-term function test demonstrated for the first time how heat can be efficiently generated and used from surface water all year round.

Website Aqva Synergy

The 2.5 meter high thermometer on the façade of the ILK Dresden is inaugurated together with the head of Dresden's economic development department, the students of the Kreuzgymnasium and all employees.

Institute director Franzke sees the 2.5 meter high thermometer on the corner of Bertolt-Brecht-Allee and Mansfelder Straße as a symbol of “world-renowned research in the middle of Dresden’s Striesen” – a district to which the ILK scientists feel deeply connected . “This local connection gave us the idea of giving Dresden residents more insights into refrigeration and air conditioning technologies.”

"Excellence from zero Kelvin" - self-confident, young & transparent - the new external image of the ILK Dresden

The rejuvenation of the workforce at the ILK Dresden, which has already taken place and is still being sought, requires new perspectives. In autumn 2021, the management decided, in close coordination with the public relations department, under the leadership of Daniela Koch, to modernize the institute's external appearance.

Together with all employees and the logo designs from the Ajete Elezaj design office, the corporate design of ILK Dresden is being further developed and a new claim is being established: “Excellence from zero Kelvin”.

The guiding principle reflects, on the one hand, the high quality standards of the institute and, on the other hand, the enormously wide spectrum, the scale of scientific research areas. It is the intellectual and economic recipe for success of the ILK Dresden.

At the same time, the institute remains true to its values of “researching together – strengthening the economy – creating perspectives”.  

At its meeting on 26.11.2019, the Board of the Verein zur Förderung der Luft- und Kältetechnik e.V., as the sole shareholder of the ILK, passed the baton of sole management of the ILK from Dr. rer. nat. habil. Ralf Herzog to Prof. Dr.-Ing. Uwe Franzke.

On this occasion, the Board of Directors recognized the great achievements of Dr. Duke honored by the ILK Dresden. Dr. In his role as managing director and institute director, Herzog has led the institute into a recognized, economically stable, non-university research company with 150 employees since the company was founded on December 21, 1990. For his great services to the ILK Dresden, he will in future have the title of "honorary director of the institute".

Dr. Goldberg and Dr. Hempel become authorized signatories.

KETEC is an innovative platform for research and development as well as education, which has the potential to find new solutions to the current challenges of the energy transition and thus further strengthen Saxony's and Germany's innovative power in the sector.

Since 2012, the company Thermofin, the city of Reichenbach im Vogtland and Saxon experts in the field of refrigeration and air conditioning technology have been working to strengthen research, development and training in Saxony. The special efforts of the city of Reichenbach led to the signing of the declaration of cooperation with the following partners in 2019:

• Free State of Saxony - Prime Minister Michael Kretschmer,
• Vogtland district,
• City of Reichenbach im Vogtland,
• Bundesinnungsverband des Deutschen Kälteanlagenbauerhandwerks,
• Saxon Guild of Refrigeration and Air Conditioning Technology,
• Corporate group Bildungswerk der Sächsischen Wirtschaft,
• ILK Dresden,
• Saxon Vocational Academy,
• Technical University of Chemnitz.

The Fraunhofer Institute for Solar Energy Systems joined the consortium in fall 2019.

The Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) has awarded the German Refrigeration Prize for the sixth time.

Together with its cooperation partner EAW Energieanlagenbau GmbH, ILK Dresden was able to score points in the most competitive category of refrigeration and air conditioning innovation: Both companies were awarded second place for the development of a new type of absorption refrigeration system using the environmentally friendly refrigerant water.

Absorption chillers use surplus heat from power generation (CHP), industrial waste heat or solar heat to provide cooling for air conditioning and process cooling with the lowest possible electricity requirement.

In the new WEGRACAL C generation of systems, which was presented by EAW in October 2017, compact plate heat exchangers were used for the first time. This allows the system volume to be reduced by 40% with the same output. In addition, the amount of material used has been reduced and internal power consumption has been cut even further.

Natural refrigerants have long been the focus of ILK Dresden's scientific work. In 2018, the institute developed and built the first performance test bench for semi-hermetic propane compressors.

The institute was already familiar with handling flammable refrigerants at this point, but the team from the "Refrigeration and Heat Pump Technology" division still achieved a completely new level of quality with the project planning and construction of this test bench:

At the customer's request, individual areas of the test bench had to be constructed in explosion-proof design. Another new feature was the complete accommodation of the test bench in a container, so that it could be placed on the customer's premises "on a greenfield site".

The safety concept was planned and implemented in close cooperation with the approved inspection bodies of the ILK Dresden as the manufacturer and the customer as the operator.

With effect from January 1, 2018, Prof. Dr.-Ing. Uwe Franzke took over the position of Managing Director at the ILK Dresden and, together with Dr. rer. nat. habil. Ralf Herzog to manage the company.

Prof. Uwe Franzke has been with the company since 1991 and has worked as an authorized representative and division manager for the main air and air conditioning technology division since 2000.

As part of his managing director role, Prof. Franzke devotes himself to business administration, while Dr. Herzog fulfills the tasks of research and external impact of the ILK Dresden.

Environment Minister Barbara Hendricks presented the 10,000 euro prize for the best innovation to ILK project manager Marcus Honke on April 11, 2016.

ILK Dresden took first place for the best innovation in 2016 with its liquid ice-based system for the efficient storage and distribution of cold. Mathias Safarik and Marcus Honke, who played a key role in driving this development forward, are delighted with the recognized achievements: "This award is an incentive for us to continue driving forward the development and market launch of vacuum liquid ice technology, combined with the hope of attracting users for further pilot systems."

After a four-year break, the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) once again awarded the "German Refrigeration Prize" in 2016. The award is endowed with a total of 52,500 euros and is aimed at companies and individuals who develop and implement particularly climate-friendly, i.e. low-emission, measures in refrigeration technology.

Shortly after the founding of the SIG in Saxony, the joining of forces also takes place at a national level. On April 30, 2014, the German Industrial Research Association KONRAD ZUSE e.V. is founded in Berlin. The ILK Dresden is one of the 66 founding members.

In total, there are around 130 non-profit, privately organized research institutions across Germany. ZUSE thus forms the third pillar in the German research landscape - alongside the universities and the four major research associations. As the competent voice of this third pillar, it will continue to grow to almost 100 members in the coming years. It is a research partner for SMEs.

As a practical and creative source of ideas for German SMEs, these institutes translate scientific findings into applicable technologies and thus prepare the ground for innovations that make German SMEs successful worldwide.

The SIG was founded in April 2014 to pool the strengths of the industrial research institutes in Saxony - with more than 950 employees. With around 150 employees, the ILK Dresden is one of the largest institutes of the 18 founding members.

In 2013, all SIG institutes generated around 82 million euro in revenue.

As part of an accreditation procedure in accordance with DIN EN ISO/IEC 17025, the ILK Dresden testing laboratory was officially awarded this competence.

In 2009, the heat pump testing laboratory (PLWP) at ILK Dresden was recognized for the first time as part of an accreditation procedure in accordance with DIN EN ISO/IEC 17025 by DAP Deutsches Akkreditierungssystem Prüfwesen GmbH, the test procedure-compliant competence for "Determining the heating and cooling capacity of water/water and brine/water heat pumps".

Services of the PLWP

In January 2008, the first research project for a vacuum ice store, a process for ice production and ice production using the direct evaporation process with water as a refrigerant and a mechanical compressor is approved for the ILK Dresden.

The potential for our society's energy industry is enormous. For example, highly efficient storage using “cold/liquid ice” can be used to store renewable energy, e.g. from wind turbines. There are also many other possible applications: https://www.ilkdresden.de/ services/products-and-prototype-construction/project/vacuum-liquid-ice-technology

The ILK already has many years of experience in the field of “water as a refrigerant”. In order to deepen this branch of research, the new main area HB5 “Applied Energy Technology” is being founded. Under the leadership of Dr. Albring the first systems are developed.

A first pilot system will be put into operation at the West Saxony University in Zwickau in 2014. It is used for load management in the university's cooling supply.

In the following years, additional, more powerful systems will be built in a laboratory building and at the University of Göttingen.

In 2016, the ILK Dresden received the German Refrigeration Prize for this development: https://www.co2online.de/ueber-uns/campaigns-projekte/deutscher-kaeltepreis/5-deutscher-kaeltepreis/

The “vacuum liquid ice cream” phenomenon:

Special steam turbocompressors developed by ILK Dresden are used to produce vacuum liquid ice cream. Why? When making ice using the so-called vacuum ice or triple point process, water is evaporated from a free water surface at around -0.5 °C in a vacuum. Energy is removed from the water and ice particles form. The more water is evaporated, the more ice is created in the water-ice mixture - the liquid ice.

In addition to thermal factors, the thermal comfort of rooms also depends on the air quality. In the Federal Chancellor's office, the quality of the ventilation was measured using volume flow measurements and the distribution of air in the room was assessed using tracer gas.

The assessment of ventilation in the room with regard to indoor air quality must therefore be based on two abilities, which are summarized in the concept of ventilation effectiveness:

• to replace the existing (used) air with fresh air
• to remove the air contaminants present in the occupied area

Based on the results, another measurement took place in the Federal Chancellor's Office in June 2006. In this case it was an acoustic analysis. The office areas of the Federal Chancellery are equipped with mechanical ventilation. As part of the revision of these air conditioning systems, it was determined that the planned air volume flows were not being achieved, so retrofitting was sought. Due to the direct dependency between volume flow and sound power, an acoustic analysis should be carried out before the conversion in order to prepare the decision on the extent of the retrofitting.

In the following years, further projects followed in the government district, such as:

Displacement air carpet measurement in the Federal Chancellery, cooling load calculations, measurements in the plenary halls, etc.

When the Gläserne Manufaktur was commissioned, its core business was the production of the "Phaeton' - a luxury-class saloon. High demands were placed on the architecture and technology, as the factory is located right in the center of Dresden.

As a regional energy company of the city of Dresden, DREWAG was commissioned to supply the Gläserne Manufaktur with the required media. The ILK Dresden was consulted for the cold water supply with natural refrigerants. The advantage of water as a refrigerant is obvious: it is available everywhere, inexpensive, easy to handle and non-toxic.

The chilled water supply is still used exclusively for room air conditioning. Four main units are available for this purpose: Two Aqua-Turbo chillers, each with a cooling capacity of 1,000 kW, which use water (R718) as a refrigerant. An absorption chiller with a capacity of 1,400 kW and the refrigerant water/lithium bromide as well as a separate compression chiller with a capacity of 500 kW. A special feature is the two-wire system for HEATING and COOLING. Depending on the load situation, the built-in radiant ceiling panels can be used for cooling in summer.

The Aqua Turbo technology scores with the following advantages:

• future-oriented and environmentally friendly
• chemical-free refrigerant
• extremely fast maximum cooling capacity output
• Investment savings due to lower recooling capacity
• Lower evaporation water consumption
• Lower conditioning agent in the cooling water system
• Predominantly simple commercially available components

Dr. Herzog continues to manage the company and grants Dr. Franzke power of attorney. Franzke becomes a member of the management.

With effect from August 1, 2000, the sole management of the ILK Dresden to Dr. rer. nat. habil. Ralf Herzog, as the previous co-directors Prof. Heinrich and Dr. König retired. Prof. Dr.-Ing. Uwe Franzke was granted power of attorney.

The German pavilion was cooled with R718 turbo chillers - developed and installed on site by the ILK Dresden.

The "EXPO 2000" was held under the motto "Man, Nature and Technology - A New World Emerges" and had around 18 million visitors. The exhibition took place in Hanover from June 1, 2000 to October 31, 2000. The German Pavilion was designed by the architectural firm Wund Friedrichshafen and had a total area of 17,000 m².

The German pavilion was cooled with R718 turbo chillers from ILK Dresden.

Further R718 chillers are in operation at the University of Essen, Daimler Düsseldorf and the VW Manufaktur Dresden.

The "BIG 5 SHOW" is one of the largest trade fairs in the United Arab Emirates. In 1999, the ILK Dresden presented its solar refrigerated container there and met with great interest.

During the "Big 5 Show", not only the solar technology with innovative applications of the ILK Dresden was presented, but also a variety of other research work.

Under the leadership of division manager Rainer Rudischer and a local agent (MENASCO), the self-sufficient solar water cooler was sold directly on site after extensive negotiations.

As early as 1995, 32 PV modules were installed at the ILK Dresden as a façade system with 7 kWp for research purposes - the largest system in Dresden at the time.

A photo shows the yellow module - a self-sufficient solar measuring station - which was put into operation in Tharandt by Rainer Rudischer. In addition to the use of electrical energy, back-ventilation for cooling the modules and thermal utilization of waste heat was investigated.

With the establishment of a SmartGrid laboratory, the inverters were replaced in 2016 and the PV system was integrated into the ILK Dresden laboratory. Despite age-related performance losses, the system is still in operation after almost 30 years.

Basic research and applied research go hand in hand

Even in the early years of its foundation, the institute's own philosophy of the symbiosis between basic research, in particular physics, chemistry, materials technology and design, and the institute's responsibility for applied, industry-oriented research and solutions was consolidated.

It was not until 30 years later - in 1994 - that this philosophy was put in writing.

This philosophy formed the decisive basis for the success of the ILK Dresden.

"Water as a refrigerant for large refrigeration systems and heat pumps" was the topic of the first Dresden Colloquium on Refrigeration Technology back in 1994. The event took place in the institute's main building.

The event was held in the Institute's main building and was so well attended that the colloquia are still held in Dresden every two years.

The editors of the trade journals "Luft- und Kältetechnik" and "Ki Klima Kälte Heizung", Professor Heinrich and Professor Steimle, merged the two journals to form the new journal "Ki Luft- und Kältetechnik" as of January 1, 1994.

Ki Luft- und Kältetechnik is published monthly and is still on the market today. The editorials are written by the current Managing Director Professor Uwe Franzke.

Together with the VDI, the ILK Dresden organized its first colloquium on air pollution control. The topic of this event day in the Dresden Blockhaus was "Filtering separators".

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The institute achieves an annual turnover of DM 13.8 million. The main building is to be renovated and extended. The construction of a new test hall is also planned.

Shortly after its privatization, the ILK Dresden achieved an annual turnover of 13.8 million DM (German marks) in 1993.

The calm before the storm - lots of green meadow, a few wooden barracks, an old test hall - but then: While research work is ongoing at the institute, the renovation work on the main building begins, the demolition of the roof, the addition of one floor, the demolition of the wooden barracks and the construction of the test hall. The seniors of the ILK Dresden refer to this time as the “Wild 90s of the ILK Dresden”.

04/08/1994 – the trees have to move too

09/30/1994 – Cooling towers are coming

December 7, 1994 – Foundation for new test hall is poured

03/16/1995 – Topping-out ceremony for the test hall

June 15, 1995 – Opening of the test hall

The Verein zur Förderung der Luft- und Kältetechnik e.V. buys the institute from the Treuhandanstalt Berlin for one German mark on April 23, 1993.

As part of the privatization, the Treuhandanstalt Berlin financed the renovation of the office and laboratory building and the new construction of the test hall. With the repurchase of this property from the Treuhandanstalt Berlin in 1996, the entire privatization process was completed.

Receipt: Transfer order (1 DM) to Commerzbank

The new logo was designed by Rolf Roeder. It symbolizes two intersecting streams of fabric or energy in the colors green and blue. In 1996, the registration of the trademark is confirmed by the German Patent Office.

Outwardly, the institute developed an aggressive market strategy, which was based on the fact that the institute was “unique in its diversity and professional expertise” (assessment by Prof. Fritz Steimle from the University of Essen, who had known the ILK since 1966) in the German market Research landscape finds a place if the remaining potential is used purposefully and ideas are developed.

A now legally protected logo for the new institute was designed by long-time ILK designer Rolf Roeder. It symbolizes two intersecting material or energy streams in the colors green and blue, which, along with the basic color white, were chosen as the institute's colors as part of the corporate design. White symbolizes pure air, blue stands for the cold and green represents environmental protection in the philosophy of the ILK Dresden.

The Federal Ministry of Economics and the Federal Ministry of Research provided funding of around 1.5 million DM (German marks) for 1990 upon application, thus confirming the research activity.

• Environmentally friendly, rational energy technologies,
• Environmental protection technologies,
• Safety and quality of life.

"If this valuable institution were to be lost in the context of German unification or were to disintegrate into individual parts, it would be an irreparable loss for the whole of Germany." Prof. Fritz Steimle from Essen in May 1990 on the continued existence of the ILK Dresden

On behalf of the Treuhandgesellschaft Berlin, the evaluation for research GmbHs was carried out in July 1991 by the Society for Economic Development (GEWIPLAN) Frankfurt/Main. As a result, it was recommended that the institute with 120 employees be retained.

The Board of Trustees of the Institute for Air and Refrigeration Technology was established in 1991 as an advisory body for the management of the institute. Some of the members joined together to form the Association for the Promotion of Air and Refrigeration Technology, which, under the chairmanship of Professor Fritz Steimle (Essen), took over all of the institute's shares in 1992.

Water is the oldest known refrigerant. It is used in a variety of ways in absorption refrigeration systems and in steam jet rotary systems. Research and development work on the use of water as a refrigerant in compression chillers began at the ILK Dresden in 1991.

The challenge: Compressors for water as a refrigerant must draw in a volume flow that is up to 300 times greater for the same cooling capacity. The pressure ratio is twice as high as with NH3.

The advantage: Chillers that use water as a refrigerant operate with higher coefficients of performance and lower energy requirements than compression chillers with conventional refrigerants, as there is no heat exchanger between the circuits.

The result is a ready-to-use, compact chiller in the output range between 300 kW and 1,000 kW that can produce chilled water between 0 °C and 20 °C. An ice-water mixture can also be produced in the direct evaporation process. The compression chiller with water as a refrigerant is therefore a serious alternative in refrigeration technology.

Professor Heinrich's willingness to take over the management of the institute he had established in 1964 was a decisive step towards privatization.

Within the research area, the idea of engineering changed to the goal of re-forming the institute. Since this idea was supported by the majority of employees, Prof. Heinrich from TU Dresden was also able to be won over.

On December 21, 1990, the “Institut für Luft- und Kühltechnik GmbH” was spun off as a subsidiary of ILKA Luft- und Kühltechnik GmbH.

As managing director, Prof. Dr.-Ing. Günter Heinrich, who at the same time became director of the institute again, Dr.-Ing. Peter König and Dr. sc. nat. Ralf Herzog ordered.

The entry in the commercial register as an independent research institution with a non-profit orientation and a name change to “Private Institute for Air and Refrigeration Technology” registered on October 10, 1991 took place on June 4, 1992 under HRB 6118. Indirectly, the ILK Dresden was still a trust company.

Unexpected experience:

First IIR-B2 conference EAST-WEST will take place in Dresden!

This conference was prepared in cooperation with the ILK Dresden before the fall of the Wall, which made the encounters in Dresden in 1990 all the more pleasant and at the same time unexpected.

The Kombinate disintegrate. The Treuhand Act comes into force. Windows 3.0 from Microsoft conquers the market. Germany celebrates reunification. Professor Heinrich returns to the ILK Dresden.

The Treuhandanstalt, founded in March under Hans Modrow, was supposed to unbundle the large combines. A pluralistic model of social, cooperative and private ownership structures was outlined. This plan was scrapped after the first free election. On June 17, 1990, the Trust Act was passed under Lothar de Maizière in close coordination with the federal government. With reunification on October 3, 1990, the Treuhand became an institution under public law and was subordinated to the Federal Ministry of Finance.

With the collapse of the combine in 1990, the Institute for Air and Refrigeration Technology was re-established as a non-profit research GmbH, initially as a subsidiary of ILKA Luft- und Kühltechnik GmbH. During the transition from the planned economy to the market economy, research orders from the former combine companies declined and there were no reliable statements regarding state research funding either.

Therefore, the research area in which the ILK was integrated began to be reorganized into an independently operating engineering company that was largely oriented towards contract research for industry.

According to an assessment of the market situation, a significant reduction in personnel from the previous 500 to around 170 employees was necessary.

Necessary dismissals only took effect on July 1, 1991 following the outcome of collective bargaining by IG Metall on July 19, 1990, or for Saxony only on July 1, 1991. In the meantime, short-time work had to be introduced, with zero working hours for the terminated employees and 60% for the remaining employees. Full-time work could only be approved by management if there was a secure order situation or operational necessity. The short-time work allowance was set at 85 or 90% of the net wage without loss of work.

At the end of October 1989, the Combine management acknowledged fundamental problems such as supply shortages, discontinuity in production, egalitarianism in wage policy instead of applying the performance principle, and difficulties with business trips to Western countries.

Discussions about political events took up more and more space in the work collectives. Suggestions and demands from employees for economic changes were initially answered with the already effective self-generating measures.

Reforms and changes were acknowledged as necessary, but they should build on existing positive conditions. A period of discussion began in the SFT about improving work, planning with real requirements, streamlining work processes and eliminating unnecessary processes and requirements.

Interesting for the employees were the questions of performance evaluation and remuneration, award principles, but also the motivation of the work and the meaningfulness of the competition management and the “collective of socialist work” movement.

The General Director held a discussion with managers and employees and declared his willingness to make fundamental changes and develop a new management strategy. A period of discussion began about improving work, planning with real requirements, streamlining work processes and eliminating unnecessary processes and requirements.

In the end, all of these approaches were not enough. During the peaceful revolution in the fall of 1989, professional work at the ILK Dresden continued, but the total collapse of the combine was already foreseeable.

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Many innovative ideas of ILK Dresden were used in the reconstruction of the Dresden Semperoper in the 1980s.

Among other things, we were looking for an intelligent solution for the micro-air conditioning and ventilation of the auditorium, which should be subordinate to the historical surroundings and ambience and should be as invisible as possible.

Based on this requirement, the engineers at ILK Dresden developed a ventilation system that was integrated into the supporting elements of the seating. The prerequisite for this was, among other things, a slightly larger distance between the rows of chairs. The demanding climatic conditions could be achieved by supplying fresh air via the back of the chair. The air is transported via a turbulence-generating grille - in the chair in the front row - to the head area of ​​the seated person - in the next row of seats. The comfortable speed of the air blower was determined experimentally in advance by ILK Dresden.

The same principle was implemented for the first time for the parapets. In addition to the auditorium, ILK Dresden was also involved in the ventilation concept of the main stage, the side stage, the adjacent functional building as well as the opera café and the theater workshops.

On February 13, 1985, the Semperoper was ceremoniously reopened with Carl Maria von Weber's “Freischütz” - exactly 40 years after its destruction at the end of the Second World War.

Mandatory subordination to parent company cuts the institute's independence - Institute Director Heinrich leaves the ILK Dresden and is appointed to the TU Dresden

In the GDR, the purchasing power of the population grew faster than the supply of consumer goods. The manufacturing companies and combines were unable to meet the increased consumer demands and absorb the purchasing power of the population. In order to increase consumer goods production in the GDR, the formation of so-called parent companies was promoted. The ILK Dresden also had to merge with the combine management and thus lost its independence once again. Reason enough for institute director Heinrich to “throw in the towel” and follow the TU Dresden’s appointment as full professor for refrigeration technology.

SFT means parent company for research and technology and should be based in the Dresden Klotzsche industrial area. The ILK Dresden was the focus of research, which was headed by the technical director, senior engineer Rolf Tanner.

At the last “information conference” (also the 100th conference since its founding) held by the institute director Professor Heinrich on December 10, 1979, he gave a review of 15 years of collaboration:

• The ILKA system developed by the ILK,
• the functional, cooperative research structure,
• excellent R&D results in recent years,
• 15 years of constant fulfillment of the plan despite often difficult situations,
• the trust of companies that has grown in recent years,
• the capacity expanded by the ex-construction,
• a concept for the development of a new generation of air conditioning and refrigeration systems,
• and the most valuable contribution: cadres who deliver high performance and tackle every task.

GDR refrigerators too good for Quelle

There were government-defined regulations (TGL) regarding the shelf life of high-quality consumer goods. For example, household refrigerators and compressors were initially required to have a service life of 10 and later 12 years. GDR refrigerators exported to the Federal Republic were soon removed from Quelle's delivery program because they worked for too long and the purchase of a new replacement device to boost sales took too long. (Source: Wikipedia/mdr.de)

Professor Fritz Steimle headed the Institute for Applied Thermodynamics and Air Conditioning Technology at the University of Essen for over 30 years. In 1990, he became the most important and recognized advocate for the preservation and continued existence of the ILK Dresden.

Despite all the political difficulties, science continues to exchange ideas around the world. Professor Fritz Steimle maintains close contact with the scientists at the ILK Dresden.

Quote from KI - magazine for refrigeration, air conditioning technology on the occasion of his 80th birthday in August 2018: "His services to the refrigeration and air conditioning industry are so diverse that any list can only be incomplete: among other things, he was Chairman of the Building Climate Association FGK for over 30 years and has had a significant influence on developments in the industry during this time. Other milestones included the chairmanship of the International Refrigeration Institute IIF, membership on the supervisory board of several companies, various offices in the German Refrigeration and Air Conditioning Association DKV, chairmanship and chairmanship of numerous committees as well as the editorship and authorship of specialist books and articles."

In 1990 he became the most important and recognized advocate for the preservation and continued existence of the ILK Dresden.

The Ex-Bau was to become one of the most modern buildings of its time in terms of energy efficiency.

In May 1977, Dr. Heinrich broke ground for the former building. The former building was intended to be one of the most modern buildings of the time in terms of energy efficiency. Its equipment: well heat pump, low-temperature heating, hot and cold water storage, underfloor heating, additional air heating, direct humidification using axial fans and many other sustainable solutions.

The first plans for a new test field had been in place since 1971; it was intended to serve as a demonstration facility for complex and sustainable energy use. Above all, however, the institute's ever-increasing space problems should be solved. There was a lack of test rooms, laboratories and office space. The new ex-building increased the institute's usable space from 6,640 to 9,186 m².

The opening of the new test areas took place on December 15, 1978 with a celebratory standing banquet for all company employees.

By the way:

The building was to be built with funds from the “Technology” fund, which required that 25 workers be hired. In addition, many of the institute's employees carried out so-called VMI construction work so that the building could be opened in November 1978. The abbreviation VMI stands for “Mass Economic Initiative” in the GDR and was a widespread form of voluntary work in the free time of individuals. These inserts were often used to expand or beautify playgrounds, sports facilities or forest paths.

Developments for the textile industry, among others Separation and filter technology are in focus

The dust-generating areas of the GDR economy, such as power plant technology, steel production, binder industry, cement production as well as the chemical and ceramic industries but also the textile industry, placed maximum demands on the air and filter technology of the ILK Dresden in the 1980s. It therefore became necessary to outsource the “dedusting” department and make it independent.

One of the department's main focuses was separation and filter technology for the textile industry. The systems had to be scientifically monitored and urgently developed further in collaboration with the manufacturers.

An example: Due to the higher amount of dust generated by the cheaper but more polluted imported cotton, yarn production (spinning mills) in particular became particularly important for dust removal and air quality control. In most countries, the maximum permissible clean air dust concentrations have been set by the workplace-related limit values (MAK). At that time, TGL 32620 applied to the GDR. The ILKA air and refrigeration technology combine with its subordinate VEB Air and Heat Technology Görlitz (LWG) was responsible for the air conditioning and dust removal equipment for the textile industry in the GDR. With the extensive experience of this company, a new system and equipment system was developed together with the ILK Dresden to meet the increased requirements and tested in a relevant textile company under extraordinarily tough operating conditions.

Good, effective stable ventilation is an important factor in keeping livestock. In the 1970s/80s, the institute developed patented stable ventilation systems for agriculture.

A good indoor climate promotes the health and performance of animals, regardless of whether they are cattle, pigs or poultry. In an environment that is too warm and humid, animals have less appetite, which can have a negative impact on their performance. Above all, there is an increased risk of infection. Due to the high ammonia and germ load in the air and poor stable ventilation, the mucous membranes of the respiratory tract can be damaged and the animals can therefore be more susceptible to infections. This can result in high treatment and follow-up costs.

The heart of the ILK Dresden stable ventilation was a ventilation device with patented materials, such as the air ducts made of wound pipe with patented special paper and a primary air box made of polystyrene.

The use of vacuum forming made it possible to produce this complicated geometric shape of the primary air box. This was used in the stable ventilation system of the VEB pig stable in Kleinbautzen. The devices also had to allow the supply air or outside air flow to be adjusted to the different load conditions. During this time, solutions for all animal species emerged with regard to free ventilation, forced ventilation or a combination of these.

The tasks of the 433 employees in the individual departments of the institute

The institute started in 1964 with 188 employees and grew to around 500 employees by 1980. The structure of 1973 was as follows:

• Coordination –  120
• Air technology – 70
• Testing – 66
• Refrigeration technology – 55
• Basics – 36
• Information science  – 35
• Design – 29
• Research Strategy – 22
• Computing technology – 15

But what was hidden behind the “Information Systems” department, for example, for which at least 35 employees worked?

This area supplied the scientific specialist media at home and abroad, interested specialist institutes and all combine companies with the

• weekly publication of reports,
• the publication of the trade magazine “Air and Refrigeration Technology”
• and the publication of the ILKA equipment, calculation and program catalogues.
• Furthermore, a multilingual “technical dictionary of air conditioning and refrigeration technology” was created here

GDR becomes a member of the IIR and ILK Dresden takes over the tasks of the National Committee

This membership was the basis for the fact that refrigeration and air conditioning technology had hardly any problems after the fall of the wall and was able to transfer almost seamlessly from the KdT refrigeration technology specialist committee to the DKV. Already at the first conference in Moscow in 1975, intensive contacts were established with scientists in the Federal Republic of Germany, which lasted for many years.

The International Institute of Refrigeration (IIR)is an independent intergovernmental organization. It is the only organization in the world that collects scientific and technical knowledge in all areas of refrigeration technology. Founded in 1908, it has built a global network of leading experts. The IIR is committed to spreading knowledge about refrigeration technology in order to improve the quality of life of all people while protecting the environment and taking into account economic needs. (Source: https://iifiir.org/ en/iir-presentation)

(Photo: Prof. Badylkes in Moscow)

ILK Dresden was responsible for the scientific and technical development of a total of 17 combine operations. The most important task was the development of the so-called "ILKA system".

The goal of the ILKA system: standardization of the isolated development of type series in the individual companies.

The solution: A modular system for all products and systems as well as synergy between automated production and computer-aided system planning.

The success: The program systems developed for optimization and simulation were used in over 10 institutions at home and abroad.

This system was given the name “ILKA System” based on its lead developer, the ILK Dresden, although the official explanation was given as “Integrating system of air and refrigeration equipment”. The basis of the system was a physically based structure of the basic process engineering processes.

The practical implementation of the system idea took place in the various product groups with varying degrees of success. For basic units such as fans, compressors and heat exchangers, filters and dedusting devices, the building block idea was relatively easy to implement. Examples of ILKA device series include the air conditioning system developed for the Babelsberg Karl-Marx-Werk, the filter systems from LFT Wurzen, the separator series from EAM Magdeburg and Entstaubungstechnik Krauschwitz or the open design of the material test chambers from Nema Netzschkau. The stable ventilation system was typical of ILKA system solutions.

Over the years, the system idea had to be gradually abandoned for some product series because the quantities in many of the combine's companies were too small for the intended standardization of large series.

The ILKA catalogs for equipment and calculations

The documentation of the components of the ILKA system was contained in the “ILKA equipment catalog.”

The latest status of calculation methods was recorded in the ILKA calculation catalog, which became an indispensable tool for all planning facilities. These calculation catalogs were widely used aids and rationalization tools, even outside the combine, since sufficient and technically specialized project planning and construction capacities were not only limited in the LuK combine. An editorial commission, in which representatives from the companies worked, ensured that the facts were presented in an application-oriented manner and thus ensured the high practical effectiveness of the calculation catalog.

It was only with the full implementation of high-performance PC technology with suitable planning software in the 1990s that the calculation catalog became obsolete as a working tool. Nevertheless, there are still smaller planning offices today that work with the calculation catalog in addition to the commercially available software.

The GDR's energy policy was geared towards minimizing the use of primary energy. Many new heat pump prototypes and experimental buildings were built as a preliminary stage to the widespread use of heat pumps planned by the Council of Ministers in 1981.

For the central economy, this was linked to the goal of examining the diverse possible uses of heat pumps and using the results to develop an energy management strategy and an extensive heat pump network for the country.

Extract from an ILK Dresden technical report from the refrigeration technology department in 1976: “By recovering heat, e.g. from the exhaust air of ventilation systems or from the cooling water of technical processes, a special utilization of the energy used can be achieved. The heat pump should be viewed as one of the options for heat recovery.”

Sustainable even back then - the energy concept of the ILK Dresden experimental building (ex-building)

Well heat pump, low-temperature heating, hot and cold water storage, underfloor heating, additional air heating, direct humidification using axial fans and many other sustainable solutions were incorporated into the energy concept, which was also a research project by the ILK Dresden. This made the former building one of the most modern buildings in terms of energy efficiency at the time!

The end of the heat pump strategy

In the mid-1980s, the oil crisis also hit the socialist states (CMEA states - Council for Mutual Economic Aid), which had already made the streets of the Federal Republic of Germany car-free in 1973, and the GDR had to invest again in the mining of its own lignite instead of itself to concentrate on heat pumps. The former building also had to be connected to an external brown coal heating plant in 1985 for base load heating.

The institute is subordinated to the VEB Kombinat Luft- und Kältetechnik (ILKA).

"In the centrally administered economy of the GDR, a combine was a group-like, i.e. horizontally and vertically integrated group of state-owned enterprises (VEB) with a similar production profile. The production, research, development and sales of an industry were combined. Their structure was intended to serve increased rationalization and improved, centralized control of production processes." (Source: wikipedia)

The formation of ILKA (VEB Kombinat Luft- und Kältetechnik) in 1970 was part of the ongoing wave of nationalization in the GDR. The aim was to boost the planned economy and make the country competitive on the world market. The formation of ILKA was linked to the conversion of LTAD (Lufttechnische Anlagen Dresden) into a parent company. At the head of a so-called parent company was a general director. In this case, the GD of LTAD. The institute was subordinated to him as a research center and lost its independence. One year later, on 31.12.1971, the institute came under the management of the combine.

However, there was one positive aspect to this process: When LTAD was reorganized as a parent company, the research department of LTAD was dissolved at the same time. The ILK Dresden benefited from this, as some of the employees were taken on. A new department was also created. The Design and Technology / Production Engineering departments were merged into the "Design" department.

The following companies belonged to the combine:

1. Stammbetrieb Lufttechnische Anlagen Dresden with Research Center - Institute for Air Handling and Refrigeration
2. Cooling plant construction Dresden
3. Air and heating technology Görlitz
4. Maschinen- und Apparatebau Schkeuditz
5. Maschinenfabrik Halle
6. Refrigeration technology Niedersachswerfen
7. Air technology Gotha Turbowerke Meißen
8. Karl-Marx-Babelsberg
9. Air technology plants Berlin
10. Maschinenfabrik Nema, Netzschkau
11. Apparatus engineering Mylau
12. Industrial cooling Zwickau
13. Entstaubungstechnik Edgar André Magdeburg
14. Rationalization air and refrigeration technology Meißen
15. Under legal independence, the companies with state participation (BSB) were assigned to the combine for planning and accounting purposes:

• Elektrophysikalische Geräte Feutron Karl Weiss KG, Greiz
• Gebrüder Kreisel und Co KG, Krauschwitz In 1971, the companies Gewerbekühlung Zwickau and Luftfiltertechnik Wurzen were also assigned to the combine.

As early as 1966, the range of development and research at the ILK Dresden was broad and characterized by the most diverse requirements of the companies and industry of the time. Some technical reports from this period have been preserved in the institute's archive:

• 31.12.1966 Technical report for the technical and economic design of provision refrigeration systems in shipbuilding
• 08.06.1967 Investigation of ring plate valves in the low temperature range for VEB MAB Schkeuditz
• 30.06.1967 Technical report on theoretical principles for the calculation of trickling film absorbers / focus on heat and mass transfer on absorbers

Photo: Absorbtion test rig at ILK Dresden

Plank is regarded as the founder of scientific refrigeration technology and is often referred to as the "refrigeration pope".

He was born in Kiev in 1886, studied mechanical engineering at the Technical University of Dresden between 1905 and 1909 and received his doctorate in 1909 under Richard Mollier.

Even then, Institute Director Professor Heinrich paid particular attention to the use of modern computing technology.

As early as 1966, relevant projects for the use of mechanical computing technology in the area of ​​energy economic calculations for ventilation and air conditioning systems began. In 1969, Heinrich formed a main computing technology department that reported directly to him.  

Initially, analog computers were used to simulate the non-stationary heat transfer and the control behavior. In 1967, the digital calculation of cooling load and energy consumption began with the D4a computer at the ILK Dresden and in parallel with the Robotron 300 at LTA Dresden.

The mechanical planning of air conditioning systems with air conditioning units had reached such a level in 1970 that this calculation was demonstrated at the ILK Dresden exhibition stand at the spring trade fair. The calculations were carried out on a BESM6 mainframe computer in Dresden, which was connected via remote data transmission.

BESM-6 was a completely newly developed supercomputer system and the first Soviet computer with an operating system. For example, he was employed at the Technical University of Dresden. A total of 355 examples were produced by 1987. FORTRAN-4 was used as the programming language. (Source: https://www.hardware-aktuell.com/lexikon/BESM_(Computer))(Photo: Victor R. Ruiz, Wikimedia, https://de.wikipedia.org/wiki/File:BESM-6_( London_Science_Museum).jpg, CC2 license, https://creativecommons.org/licenses/by/2.0/deed.de

In 1966, Werner Herrmann, a graduate designer, created a graphic design to cultivate a modest identity for the institute.

The symbol was replaced by a new logo as early as 1970.

In the early years, the institute grew by recruiting a large number of graduates from universities and technical colleges, in particular from the TU Dresden and the Freiberg Mining Academy. By the end of the 1960s, ILK Dresden employed around 400 people.

A large proportion of the graduate and doctoral engineers at the ILK Dresden were trained by Dresden university professors who had close links to the institute and represented the "Dresden School of Thermodynamics and Refrigeration" as well as building climatology. In the field of refrigeration technology, these were Professor Jungnickel until 1980, then Professor Heinrich until 1990. Air conditioning technology was shaped by the personality of Professor Petzold until 1991. The Dresden cryogenic physicists, Professors Bewilugua and then Knöner, also influenced the work of cryogenics at the ILK Dresden through their students.

On July 1, 1964, the appointment contract dated February 20, 1964 was signed between Dr.-Ing. Günter Heinrich, until then Technical Director at DKK Scharfenstein, and VVB Air and Cooling Technology as Director of ILK Dresden.

In applied research, ILK Dresden was actively involved in the development of equipment and systems in the fields of air conditioning, dedusting, refrigeration and cryogenics. The main areas of work were:

1. Spatial flow
2. Flow acoustics
3. Energy load and energy cost calculation
4. Air filter technology
5. Refrigerant compressors and heat exchangers
6. Optimization of appliances and refrigeration systems, such as cooling and freezing systems
7. Physical and thermodynamic material values
8. Control engineering and electronics
9. Computing technology

The journal Luft- und Kältetechnik was founded in 1964 by Dr. Günter Heinrich to publish the scientific findings of ILK Dresden, but also as a publication medium for ventilation and refrigeration technology and all related specialist areas.

Heinrich acted as publisher and the ILK Dresden as editor. The magazine was published by Verlag Technik in Berlin.

In addition to the technical articles from its own institute and the forewords (editorials) by the publisher Dr. Günter Heinrich, ILK Dresden not only exerted a national influence on research policy and the technical development of ventilation and refrigeration technology, but also contributed to the international dissemination of knowledge. The bi-monthly journal was exported to the then FRG, among other countries, and was received with interest and appreciation.

The design of the title page was a special feature. It was designed by the institute's designers for the corresponding main topic of the magazine.

ILK Dresden was only able to cope with the growth in test areas and the increasing number of employees with numerous external and branch offices.

The first main building of ILK Dresden was located on Karcherallee, plus an experimental area on Tharandter Straße and a branch office in Merseburg. Later, the institute had the three-storey main building on Bertolt-Brecht-Allee, of which the second floor was still used by the Institute for Chemical and Refrigeration Equipment.

The 40,000 m² open-air site (corner of Bertolt-Brecht-Allee and Mansfelder Straße), which was originally used by nurseries, also housed an old engine shed, three wooden barracks and a private "Hennig" car repair shop. Incidentally, this workshop only moved out in 1986. After the war, the engine shed was used to house the so-called Trümmerbahn. A train that was used to transport rubble after the destruction of Dresden.

After the branch office in Merseburg was closed in 1966, many employees relocated to Dresden. By the end of the 1960s, the ILK Dresden had eight parts of the institute. These buildings covered a total area of approx. 3,000 m². Parts thereof were located in residential buildings:

• Bertolt-Brecht-Allee 20 | Headquarters of the ILK Dresden
• Tharandter Str. /Gröbelstr. | air technology, test field, workshop
• Mockritz, Caspar-David-Friedrich-Str. | test field
• Trachenberger Str. | test field
• Stresemannplatz | Formgestaltung
• Bischofsweg | Documentation distribution
• Konkordienstr. | Office materials warehouse
• Breitscheidstr. | Engineering office

The new center in Dresden will have 184 positions (105 in Dresden and 79 in Merseburg&#41.

Former mandate or statute - today Sustainability Concept

The STATUT of the ILK Dresden was published in the decrees and announcements of the People's Economic Council No. 7/64, page 106, which came into force retroactively from January 1, 1964.

With this decree on the founding of ILK Dresden, an industrial branch institute was established in the Vereinigung Volkseigener Betriebe Luft- und Kältetechnik, which had the task of making a significant contribution to the intensification of production, increasing the utility value properties of existing products and developing a new product range with high quality, wide application possibilities, functional reliability and long service life with low material and energy consumption as well as low maintenance costs together with other companies in the industrial branch and in accordance with the requirements of the users.

Mansfelder Straße 26 corresponds to today's postal address Bertolt-Brecht-Allee 20. The building formerly housed the State Employment Office and later became the headquarters of the Institute for Chemical and Refrigeration Equipment.

Here stands the building of the former Saxony State Labor Office, which was bombed during the war and is now being acquired and rebuilt by Professor Jungnickel's institute.

The pace of development of chemical plant construction in the GDR can no longer keep up with economic needs. The consequences?

In May 1963, as part of the "Decision on measures to develop the capacity and production of chemical plants in line with demand to safeguard the GDR's chemical industry and foreign trade", the GDR government ensures that the national economy will focus on chemical plant construction in future. In order to achieve this, it was decided to separate the air conditioning and refrigeration plants from chemical plant construction. The organizational form of an institute for the research and development of air conditioning and refrigeration technology also seemed appropriate. The necessary prerequisites for the formation of such an institute were initially lacking, especially as the previous administration had remained within the Institute for Chemical Plant Engineering.