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CryoBlizzard - Next generation of freeze drying and blast freezing

HOF has developed a new process, which uses ambient air as a refrigerant that exceeds the current requirements for freeze drying and blast freezing in the long-run.

Currently, the entire industry is in upheaval due to the social and political rules and regulations in regard to climate change, generating a level of uncertainty for many operating companies. Frequently asked questions refer to the problem of environmental compatibility, official regulations and directives as well as the availability and price development of operating media. This concerns refrigeration in particular, as the established technologies in this field are increasingly restricted by political regulations, bans and shortages. For installations with a service life of more than 30 years, operating companies focus especially on future-proof design, reliability and quality of their plants. Energy efficiency, safety, selection of components, documentation and durability are also crucial factors.

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HOF CryoBlizzard - a technology sets new standards

As an innovative market leader, HOF always puts emphasis on customer needs and market demands. Together with Mirai Intex ( as a partner, the HOF CryoBlizzard has been developed as a new technology for our market segment.

A HOF freeze dryer from 1998 was retrofitted especially for this R&D project. The plant is a freeze dryer with a batch capacity of 40 kg for insulin production. Before this retrofit, refrigeration was achieved by two refrigeration sets, each containing 12 kg of the refrigerant R404A (GWP100 = 3922). The process plant was controlled by a Siemens S5 control system.

Great performance with homogeneous temperature distribution

The overall retrofit has upgraded the lyo to a new refrigeration process, the HOF CryoBlizzard and to the current S7-1500 control system. With this new process, the refrigeration system consists of redundant cold air machines which are connected to a central primary tank in a modular system. The primary tank supplies the consuming units, such as shelf stack, ice condenser or blast freezer directly with the refrigerant medium and can therefore provide large capacities with homogeneous temperature distribution, all within a very short time. The usage of such a primary tank results in the fact that the consumption of cooling water and the power remain constant and no load peaks occur during the supply. Additionally, the cooling water consumption was reduced by half.

Air as refrigerant is free of charge and always available

The cold air machines from Mirai Intex are chillers which operate with air as a refrigerant using the Brayton cycle process. The maximum overpressure in the machines is 3 bar(a) and can be compared to that in a bicycle tire. This makes these machines particularly safe and environmentally friendly. Furthermore, no special requirements result in regards to the machine room set-up, employee training and recurrent testing. And in addition to all this, air as a refrigerant is free of charge and always available, has a GWP100 value of 0 (zero) and is therefore not affected by any regulations.

“As an innovative equipment manufacturer, we knew thatwe have to come up with a new way forward - for our customers. The advantages of air as a refrigerant are obvious. Air is available, non-flammable, non-toxic and poses no risk of suffocation. Air has no GWP value and is therefore not subject to the F-Gas Regulation or any other directives. That is the future!”, says Oliver Fleischer from the refrigeration engineering and service management department at HOF.

The HOF CryoBlizzard turbocompressor, oil-free and almost wear-free

The refrigeration circuit is driven by an air-bearing supported, oil-free turbo compressor–expander unit that runs with up to 88000 rpm and virtually no wear. The refrigeration medium is cooled in a heat transfer unit, integrated into the chiller. The air that is heated this way, is aspirated by the turbocharger and compressed (steps 1 to 2). Subsequently, the energy in the gas chiller is dissipated to the environment and cooled down (steps 2 to 3). In an inner heat transfer unit, the recuperator, the air is strongly cooled down (steps 3 to 4) and then relaxed for effective use in the expander (steps 4 to 5). This work is returned to compression. The energy is now absorbed through heating of the air in the cold medium/heat transfer unit (steps 5 to 6). After the air in the recuperator has been heated again (steps 6 to 1), it is aspirated by the compressor and the cycle starts anew.

With HOF CryoBlizzard - renewing existing systems as a retrofit or implementing new systems

The modular design enables the capacity of the HOF CryoBlizzard to be scaled up or down as needed. This allos its adaption from small freeze dryer units all the way to a central cooling system for complete factories. Existing plants can be retrofitted and new plants can be implemented. With the HOF CryoBlizzard, HOF has developed a future-proof solution for freeze drying and blast freezing which is not only safe for employees and the environment, but also sets new standards with regard to the quality and availability of the application. Therefore, the HOF CryoBlizzard is another alternative technology by HOF to solve the GWP-issue of synthetic refrigerants in the long-run.

In cooperation with the project partners:


Refolution Industriekälte GmbH

We are especially happy, that the technological magazine „DIE KÄLTE + Klimatechnik“ has published an article about our technology already in its most current issue. Source: Alfons W. Gentner Verlag GmbH & Co. KG, Fachmagazin „DIE KÄLTE + Klimatechnik“, Article "Natürlich am besten", issue 01.2020, pages 18 - 19.

For more information on the innovative development, please contact Mr. Oliver Fleischer (Phone: 0049 6462-9169-228 - Email: oliver.fleischer(at) or any other HOF representative.

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HOF received the TOP Innovator award for the fifth time in 2020

The TOP 100 – the most innovative medium-sized German companies – were selected for the 27th time and HOF once again was among the best.

HOF had to take part in a sophisticated scientific selection process. The focus is on innovation management and innovation success.

Ranga Yogeshwar
Dorothee Bär
Prof. Dr. Nikolaus Franke

Dear Sir/Madam

Despite some new coronavirus hotspots, Germany and Europe overall are on a good track to work themselves out of this crisis. Nevertheless, we all have to stay highly alert.

In this regard, HOF continues to diligently do its homework in order to maintain the hygiene standards among employees. We would like to once again say thank you to our employees for their commitment!

Looking ahead

Despite the pandemic, we are deliberately directing our attention to the future:
whether with the announcement for the Specialist Forum 2020 this November or with our many specialists who use their great know-how and many new innovative ideas to continuously develop our capacities for our customers.
This is also reflected in the fact that HOF received the TOP 100 Innovator award for the fifth time running!

To the video >

Necessity is the mother of invention

Ranga Yogeshwar, science journalist and longstanding mentor of the TOP 100: “The coronavirus has had an immense impact on our world. It is a crisis, but we all know the saying that ‘necessity is the mother of invention’. And innovators in particular sometimes find opportunities in a crisis. The TOP 100 is about innovators, about showing how these companies have the courage to reinvent themselves, to develop new things and to thereby become a shining example for others.”

TOP 100 panel member Dorothee Bär

Minister of state at the German Chancellery

“Innovative medium-sized companies are the driving force of the successful ‘Made in Germany’ concept, and TOP 100 helps to make those companies visible who use their power of innovation to contribute to Germany’s economic success and see digitalisation as an opportunity.”

Award for the most innovative medium-sized German companies

The TOP 100 – the most innovative medium-sized German companies – were selected for the 27th time this year. HOF had to take part in a sophisticated scientific selection process. The focus is on innovation management and innovation success.

The system, which was developed by Prof. Dr Nikolaus Franke, gives equal opportunities to manufacturing companies and service providers while also taking into account the respective size of the enterprises. In this independent selection process, HOF and its around 270 employees stood out in particular on account of its innovation success.
Prof. Dr Nikolaus Franke, Scientific Director of the TOP 100: “HOF Sonderanlagenbau GmbH is consistently and fully focused on innovation. This becomes particularly evident in the external orientation, which is the way that open innovation is put into practice.”

Digital award

Due to the coronavirus epidemic, the awards were handed out over video this year. One of the presenters was Linda Zervakis, a German newsreader. “I would have loved to do this again in person, but it had to be digital this time.” Ranga Yogeshwar: “This is the fifth time I can say ‘Congratulations!’ to HOF Sonderanlagenbau GmbH for winning the TOP 100 award. Brilliant!”

HOF says thank you

“We are very pleased to be among the winners for the fifth time and would like to thank all employees for their motivation and power of innovation and of course we also thank our customers for the regular exchange of knowledge.”


Hans-Georg Hof and Dr Alexander Hof



Important about SIGRAPH and EPLAN 5

Since the existence of HOF Sonderanlagenbau GmbH all switchgear documentation (wiring diagrams) was prepared at HOF electrical engineering. From 1990 to 2004/2005 we used SIGRAPH and from 2004/2005 to 2012/2016 we used EPLAN 5, later EPLAN Electric P8.

Due to manufacturer-related changes we would like to draw your attention to the following announcements:

Sigraph announcement:

The CAE system SIGRAPH, used to create circuit diagrams until 2004, has already been discontinued by the manufacturer for some time. Economic processing of the circuit diagrams is therefore unfortunately no longer possible. We can therefore process changes in SIGRAPH diagrams only to a limited extent and must discontinue support for these circuit diagrams from 2022.

For larger modifications, we recommend converting the circuit diagrams to EPLAN P8.

EPLAN 5 announcements:

The CAE system EPLAN 5, used to create circuit diagrams between 2004 and 2016, has been replaced by the EPLAN P8 system. As of version EPLAN P8/2.8, EPLAN 5 can no longer run in a system environment. Furthermore, operation under Windows 10 is not released.
In the future, EPLAN 5 projects must therefore be migrated to P8 to enable further processing.

Bernd Becker (Head of Electronics Engineering)

"If modifications to your affected systems are planned, we will be happy to support you with a future-oriented solution."

Award: in the innovation elite for the fourth time running

HOF Sonderanlagenbau GmbH from Lohra has once again been selected as one of the best in the 26th edition of the TOP 100 innovation competition.

The company received the “top innovator” award for the fourth time running from the mentor of the competition Ranga Yogeshwar, scientific coordinator Prof. Dr Nikolaus Franke and compamedia in Frankfurt on 28 June.

HOF among TOP 100 companies again

398 companies entered the current round for a TOP 100 award.
TOP 100 uses a scientific system to evaluate the innovation management of SMEs.
This system, which was developed by Prof. Dr Nikolaus Franke, gives equal chances to manufacturing companies and service providers while also taking into account the respective size of the enterprises.
In this independent selection process, HOF and its 265 employees stood out in particular on account of its innovation success.

Finding innovative solutions – exploring new directions

For 30 years, the TOP 100 company has been specialised in the development and manufacturing of freeze drying systems, loading and unloading systems, and freezing and thawing equipment for the pharmaceutical industry. More than 2,000 systems in 27 countries prove the worldwide success of HOF.
Where bottles filled with frozen blood plasma used to be opened by people wearing gloves, this is now the task of a machine from the top innovator. The bottles are partially defrosted in an automatic process, opened with a so-called guillotine and then removed by robots for further processing of the plasma. The new innovative process from HOF is significantly faster and the system can operate around the clock.

“Being open to new things is a sign of a good innovation culture”

Physicist and scientific journalist Ranga Yogeshwar, who has been mentoring the competition since 2011, summarises the qualities of the TOP 100 as follows: “Being open to new things, tolerating mistakes, constantly striving to do things in a new and different way – those are the characteristics of a good innovation culture. A culture that is practised in the SMEs which we award with the TOP 100. They are exceptional medium-sized companies where the spirit of innovation has become part of their DNA. They are far-sighted, active entrepreneurs who focus on innovation every single day.” More information at

HOF says thank you

“Receiving the award for the fourth time running makes us particularly proud.
We do not take it for granted and we will continue our endeavours to offer our customers the best, most innovative solutions.
But most of all, we want to thank our employees, without whom this success would not be possible.”


The new LYOCOM 2018 software

HOF now uses the new LYOCOM 2018 control system as a successor for the LYOCOM III Pro software. Clearly improved diagnostic options and a standardised process overview are the crucial convincing points.

LYOCOM 2018 is based on Siemens TIA Professional 15.1. In contrast to the LYOCOM III system, all system components (freeze drying plant, vial transfer system and visualisation) are integrated in one project, so that the customer only has to manage one software version for the HOF Package Unit.

LYOCOM 2018 is a software for all freeze drying systems in combination with the loading and unloading systems and includes extensive features. The system features easy, intuitive operation, compared with a user-friendly and visually appealing user interface.

LYOCOM 2018 has the following distinguishing features:

  • Use of Siemens F-CPU 15xx
  • Uniform look and feel for operation of GT and VTS
  • Development of a dedicated HOF library as per GAMP 5. Safety through the implemented TIA portal version check and tested module documentation of standard modules
  • Fine-grained display of operating equipment down to the basic function level
  • Extended service information from display of switching cycles of the operating equipment and optional batch-based performance recording
  • Minimising of qualification work by using uniform screens, standardised program modules and a uniform text basis. Only the correct connection to the periphery has to be checked. Visualisation, error message generation, etc. are standardised and no longer require checking
  • Extended system diagnosis. Siemens ProDiag was integrated for this purpose. This now makes it possible to display control sequences and interlocks on the visualisation directly from the PLC program, to immediately initiate diagnostics in case of process errors. The control of the door safety was integrated into the GT on an F control, also in the framework of better diagnostic options. Additionally, the Siemens hardware diagnostics are visualised and a torque path of the axes can be recorded for the servo drives during the diagnosis. All system components which are actuated from the control are also visualised and, with the appropriate authorisation, can also be actuated directly or locked, e.g. for service work
  • Redundancy in communication by establishing an MRP ring already in the basic version
  • The HOF FVP software is used for recipe management and batch logging. This ensures consistency of the recipes, from laboratory applications to the production lines
  • Vertical and horizontal data interfaces are executed via Ethernet, allowing flexible interfaces to be mapped. The LYOCOM 2018 system offers interfaces to higher-level systems, e.g. MES and Data Historian. Here, the link to its higher-level system can be implemented individually with an interface to the PU
  • Use of a new touch panel with new keyboard for sterile rooms
  • Improved parameter mapping of the VTS with display of all parameters on one screen
  • Automatic setting of IPC samples using a robot

“We are pleased that we have already been able to successfully integrate the new system into several new plants.”
Patrick Schuhmacher (Head of Software Engineering)

Modern remote service solution from HOF

Due to a restriction from the supplier, HOF cannot ensure support for the connection to software used over analogue remote service modems for Windows 7 beyond 14/01/2020.

We regret that we consequently have to terminate our support commitment at this time. HOF is very aware, however, of the responsibility regarding this important issue. A reliable, modern remote service solution requires extensive specialised knowledge.

“We can provide you with an individually tailored remote service solution for your system. We would be pleased to provide you with a quotation.”

Patrick Schuhmacher (Head of Software Engineering)

(+49 6462 9169-358 /

3,800 km for a good cause – a very special report

After intensive reflection, the management came up with a very special idea for Christmas 2018. Instead of Christmas gifts for customers, they decided to pack parcels with essential food and hygiene products for people in need in Eastern Europe. Diana Hof-Schneider got into contact with the Johanniter charity, and after a few phone calls HOF was able to join the Johanniter Christmas Truckers. Johanniter have been organising aid transports to the poorest countries in Europe for 25 years.

Common ground was soon found after consulting local food retailers. The Kessler family, who run the REWE supermarket in Gladenbach, immediately offered to cooperate and supplied the required relief goods directly to the HOF premises in Mornshausen.

The parcels were filled and wrapped up in three days, by employees as well as fire fighters and the Lohra Business Forum – around 200 people overall. In the end, there were 1200 parcels with essential food products and personal hygiene items, including flour, sugar, pasta, oil and toothpaste. Lovely Christmas cards made by local nursery school children gave the parcels a personal touch.


An unforgettable adventure begins

Viele Hände helfen bei HOF
Spaß hatten Sie auch
So viele lachende Gesichter
auch die ganz kleinen freuten sich

Things started rolling on Christmas Day. The two Christmas Truckers from HOF, Alex Wagner and Alex Winter, were taken to Landshut, where the journey to Bosnia with around 20 tons of relief goods on board began at 6 am on December 26.
We were able to park our trucks on the premises of the THW [German Federal Agency for Technical Relief] in Landshut so we could start bright and early from there with the maximum driving time. First, we were joined by two more trucks that had been parked there and drove to the Grieserwiese area. Here, the convoys were assembled and supplied with food and drink to last us for a week. We introduced ourselves and were received like old friends. Then the 47 trucks drove through the mediaeval centre of Landshut, where we received a send-off with a church service and various speeches, including by German-Romanian musician Peter Maffay.
Thousands of people lined the streets and waved us off. The THW had blocked all the roads so we had unhindered access to the motorway – the atmosphere gave us all goosebumps. At the border between Germany and Austria, the convoy split off towards their destinations: Romania, Bulgaria, Ukraine, Albania and Bosnia. Our destination on the first day was Croatia, where we arrived around 9:30 pm after a 16-hour day. The next morning, we continued to the Bosnian border, where we stopped for the whole day and kept the local customs authorities busy with our relief goods.
Later that afternoon, we were able to continue the journey to Bosnia. Our destination was Tuzla in the east of Bosnia, close to the Serbian border. After a long search with our six trucks, we were warmly received at the local university and invited to dinner.

The next morning, we split up to distribute the Christmas parcels in five different locations: four schools and nurseries along the Serbian border and a women’s shelter with numerous children. Getting to the nurseries or schools was not always easy, as the mountain paths were often overgrown and had to be cleared with a chainsaw. Many hands helped us with unloading. People were overjoyed to receive the parcels, as they provided them with essential items for themselves and their families, even if only for a short while.
After another night in Tuzla, we unloaded two more trucks on the following day before setting out for Banja Luka. We drove 200 kilometres across the mountains on roads that reminded us of East Germany before the reunification.
Once we arrived in Banja Luka, the last two trucks were unloaded and we started our journey home.
Our convoy stayed together until we reached the Obere Tauernalm services in Austria, where we said goodbye after a lovely dinner together – some of the trucks had to go in a different direction from there. For us, the day ended at 1:30 am at the Chiemsee lake, where we were warmly received at the Schalchen Hof Hotel with a little late-night snack. The next day was New Year’s Eve, and after a generous breakfast we started on the last leg of our journey. Our Bosnia adventure finally came to an end at 6:30 pm on New Year’s Eve, and were happy to be reunited with our families.
We can say that this aid campaign by HOF was a great success all around. We saw that our parcels actually arrived where they were meant to go – to the poor, children and others in need. When you see how a small bar of chocolate or a colouring book can put a smile on a child’s face – which we did – then we think that is proof that our company did exactly the right thing.

Alexander Wagner & Alexander Winter

Relying of knowledge and experience – 30 years HOF

Dear ladies and gentlemen,

on October 1, 1988, the company “Schäfer & Hof Vakuum und Kältetechnik Sonderanlagenbau GmbH” was founded in a former cigar factory in Lohra, city in the central Hessen.

This is not necessarily a jubilee in the classic sense of the term, but it is a remarkable milestone in our company history, of which we can be very proud.

Always think ahead ... that is the maxim that always drives HOF forward to always technologically “think outside the box” – always looking the best solution for its customers.

HOF now looks back on more than 30 years of company history.
Since its founding in 1988, HOF has continuously developed into a globally operating and innovative company in the manufacturing of individual freeze-drying plants, loading & unloading systems and freezing and thawing equipment.

Step by step and always focusing on the essentials, the company has positioned itself as a market-oriented company, and has been for more three decades now the leading specialist for individual solutions in the pharmaceutical and biotechnological industry, with more than 270 employees within the HOF group.

We sincerely thank you for 30 years HOF Sonderanlagenbau GmbH and would like to thank all business partners who have accompanied us on this way for the good and successful cooperation.

Special thanks go to our customers for their trust and longstanding loyalty, and above all to our employees for their engagement and work, without them, we could not share our success. Therefore we are proud and grateful for the work they do each day.

We look forward to what is still to come and to the next years with you.

Yours sincerely
The HOF family

"Detailed information about our company anniversary can be found in our latest issue of HOFinsight."
Dr. Alexander Hof (management)

More about that here…

HOF company history 1988 – 2018

Sometimes things don’t turn out as planned

According to the original idea, HOF (or Schäfer & Hof – Vakuum und Kältetechnik Sonderanlagenbau GmbH, as it was when it was founded in 1988) was to become a nationally active service company, offering and providing services in the form of maintenance and modifications for existing freeze-drying plants.

However, this service company never existed in this form, because when the company was founded the order for the construction of a new freeze-drying plant was placed directly. So, from day one, the business model was based in the mechanical engineering sector, and it was always clear that service in any form would have to play a key role.


A strong team, the right knack and the necessary amount of luck meant that the available space had already been used up in the business’ second year and a large assembly building was erected. Since then, the company premises have been expanded in several stages to create a total building area of 13,500 m² at three sites.

Challenges: our driving force

HOF’s development has been constantly accompanied by the growing demands of the pharmaceutical and biotechnology industries. At the same time, it was always our customers’ challenges that served as the driving force for innovations and further developments. In addition to solutions in the field of freeze-drying technology, pioneering HOF products such as freezing and thawing equipment for blood plasma in blood donation centres, effective systems for loading and unloading freeze-drying plants, freeze-thaw units for tempering pharmaceutical and biotechnological products and, most recently, thawing and cutting devices for bottled plasma were developed.

Our philosophy

With the basic philosophy of offering and delivering “on-time quality for discerning customers”, after a 30-year company history HOF is today the leading specialist for individual solutions. This much is underlined by the innovation and management awards that HOF has received in recent years.

Letting knowledge grow

In keeping with this doctrine, HOF attaches a great deal of importance to training specialists and has been a training company for over 25 years. In addition to offering the classic skilled occupations in the commercial and industrial segments, HOF has been a university partner for the Dual Study integrated degree programme and other degrees for many years.
In-depth specialist knowledge, many years of experience and a high degree of flexibility, coupled with short decision-making paths and the spontaneity of a medium-sized, owner-managed family-run business, have made HOF strong – not only in the field of plant engineering, but also in the all-important area of service. This has been just as important as plant engineering since the company was founded, and, like the company, has been steadily expanded over the years.

Today, HOF manages more than 2,000 plants – both its own and ones from third-party manufacturers – at international level. With knowledge and experience, crucial quality and the familiar flexibility we’re known for, HOF will remain a stable partner in the future as a specialist for individual solutions.

More about that here…

Hans-Georg Hof takes a look back

It all started in what was formerly a cigar factory

At that time, we spent a long time humming and hawing over whether acquiring such a large building would be worthwhile. I never thought that we’d have to contend with our first extension in the second financial year due to a lack of space – let alone today’s dimensions.

Where 260 employees work today, in the early days I was a salesman, planner, electrician, locksmith, commissioning engineer, service fitter and manager all rolled into one. Although nowadays I primarily deal with strategic matters, I don’t let myself miss out on my daily walk through the workshop or tinkering around in one way or another.

The foundation of HOF Prüfsysteme GmbH
We founded HOF Prüfsysteme GmbH on 1 April 2004 through private connections and the roots of my professional career in the freeze-drying technology sector. In this company, we primarily serve the automotive industry with our leak testing systems. As a corporate group, we have been working hand-in-hand ever since and complement one another with both limited companies.

Successful attendance at trade fairs
We have been an integral part of ACHEMA in Frankfurt since 1994. Although my feet usually hurt on the first evening of the trade fair, we can always look back on a very successful attendance. What I’ve always liked – and still do like – most about this is the contact with our existing customers and the related opportunity to exchange ideas in both a business and a private context.

Sustainability and treating nature with respect are particularly important to me as an amateur farmer
Straw – the by-product created during cereal growing – can be put to more sensible use than being left chopped in the field. It took several years to get from the initial idea to the actual implementation process, but since 2013 we’ve been able to heat our Mornshausen site completely with straw.
The fact that the complete value creation chain – from cereal growing and pelleting the straw, to using the pellets in the heating system – comes entirely from a single source was a one-of-a-kind pilot project in Germany and therefore a milestone that makes me puff up with a certain feeling of pride.

A heavenly gift
On our company’s 25th anniversary, we held a large family day in addition to our first HOF Specialist Forum. During the festivities, the staff surprised my wife and I with a balloon ride, which we took a short time later.
The fact that we were able to maintain our team integrity and personal connection to one another – even after 25 years – and were thanked with such a beautiful experience truly was and is a special gift.

Always a highlight
Whether it’s a 0.5 m² laboratory plant, a 40 m² production plant, a compact FTU or a delicate loading and unloading system – integrating our solutions into our customers’ buildings is always a very special event every single time and has required us to come up with lots of extraordinary ideas in the past.
It’s all about overcoming challenges, particularly in existing buildings with specified access routes – and a task which I personally always really enjoy and am happy to take on.

More about that here…

Any questions?