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Cool Talks: "We have been fans of natural refrigerants for 125 years"

20.08.2021 , News :

Monika Witt is an enthusiastic advocate of natural refrigerants, not least in her role as Managing Director of a long-established German refrigeration company and board member of eurammon. We spoke to her about her motivation, her role in the family-run business and why we need a reality-check for safety regulations.

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WITT is celebrating its 125th anniversary this year - first of all, congratulations! Mrs. Witt, you are the Managing Director in fourth generation. Was it clear to you from the start that you also wanted to join the family business?

I am lucky that my father did not pressure me at all. The company was always present, but I was free to make my own decisions. However, after graduating from school, I decided to study mechanical engineering. I guess as a daughter you always try, maybe subconsciously, to impress your father. And a technical degree was the best choice to do so.

During my studies, I was particularly interested in ecological topics and therefore wrote my diploma thesis on the denitrification of drinking water in a bioreactor using bacteria to remove harmful nitrates. After graduating from university, I consequently wanted to work for a company involved in water and soil treatment. However, I actually ended up in the field of cryogenic cooling by coincidence and built air separation plants.

During my first job, I had the opportunity to work in the US for three years. When I told my father that I would like to extend my stay for two more years, my father confronted me with a choice: I would either get into the family business on the occasion of the 100th anniversary in the following year, or he would sell the company – something that had never crossed my mind. The choice was therefore easy, and I never regretted it.

Cool Talks

opens in a new window)In our "Cool Talks" interview series, members of the Green Cooling Network share their vision of Green Cooling. The Network is an alliance of key players in the refrigeration, air-conditioning & foam sector. It comprises government institutions, international organisations and the private sector. They are united on one goal: the transformation of the cooling sector – for the benefit of people, the environment, and our shared future.

25th anniversary

So this year you are celebrating your 25th company anniversary. Congratulations on this as well! What has been one of the most memorable experiences during your career?

Thank you! Yes, it has been 25 years on the first of May 2021. Thinking about my most memorable experience… It's hard to say, there are quite a few. Maybe at the beginning, when I was responsible for a multimillion budget and, as a greenhorn, I was afraid of making mistakes. But then I told myself that mistakes are necessary for your development process, and my employer would have assessed the risks and found them acceptable.

You also mentioned that you have always been interested in ecological issues and that your thesis was in this area. Why do you personally care about our environment?

I have always cared for the environment and always wanted to work in this area. We all see what environmental damage means and the issues of pollution and global warming are now more and more in the public consciousness and intensively discussed. It is important to keep the world in a state that future generations would also like to live in. And as an engineer, I am naturally interested in finding solutions to complex problems.


WITT is a family-owned and managed company that has been providing the refrigeration industry with proven and custom-fit products and solutions for 125 years. The company is specialized in pumping liquid refrigerants with to some extent gas content, separation of gas from liquid refrigerant and oil recovery from the refrigeration cycle. Energy efficiency and environmental friendliness are always priorities in WITT’s product development. Therefore, WITT has preferred natural refrigerants such as ammonia (NH3) and carbon dioxide (CO2) since its establishment. These refrigerants offer customers advantages from both an energy and an ecological point of view.

Safety aspects

WITT has focused on sustainability from the very beginning. That was not something that could be taken for granted 125 years ago. Do you know what the motives of your great-great-grandfather were back then?

WITT worked with ammonia from the very beginning because it was simply the best refrigerant in terms of thermodynamics. More than 125 years ago, people probably didn't give much thought to the environmental aspect. But ammonia was also easy to handle and predestined for high performance. My great-great-grandfather first provided refrigeration for breweries. In the following generations, the company focused more and more on industrial refrigeration. “Safety refrigerants” (editor’s comment: HFOs, HFCs) were never a topic of discussion. They were less effective, more expensive to buy, simply not suitable for the industrial sector. We have always been fans of natural refrigerants.

Speaking of safety: What would you say to people who think natural refrigerants are too risky to handle?

Mankind has had to learn how to deal with hazardous substances from the very beginning. This starts with the handling of fire - which is also not completely harmless. You have to weigh up how great the risks are compared to the benefits. With natural refrigerants, it is now increasingly recognised that the benefits are significantly greater and the risks manageable.

I can honestly admit: We have already had accidents with ammonia in our company. They mostly happened when technicians were not careful enough. But if you treat the consequences of accidents immediately (rinse out ammonia in the eyes immediately with water, for example), there is no permanent damage. We sometimes joke: our mechanics all live to be very old, usually 80 or 90 years. Probably because the cold preserves them well.

In your keynote at the Green Cooling Summit 2021, you said it was absurd that propane is used by amateurs for camping or barbecuing, but trained technicians are only allowed to put small amounts of propane into professional refrigeration systems. Do we need more reflection on safety standards in practice?

Absolutely! Don't get me wrong: security standards are extremely important for safe handling, but we should not make a distinction between private and business sector. Necessary safety standards must be reasonable and adhered to everywhere. And we must learn to assess risks and take the necessary measures to minimise them.

Future cooling sector

Monika Witt in one of the company's production halls

There are so many examples that show that safe handling of flammable or even toxic substances is possible: Isobutane, for example, is flammable and is now used in almost all refrigerators around the world. In the beginning, the chemical industry questioned whether safe handling could be guaranteed, and after 30 years of operation, nobody talks about it anymore because it has proven to be safe in practice.

According to your keynote, “the future is natural" and "leapfrogging" is the smartest choice. How do you envision the ideal cooling sector of the future?

The ideal cooling sector does not exist. There is an ideal refrigerant and an ideal process for every application. You can't generalise. The fact is: Natural refrigerants are available for at least 95% of applications.

The technology is there in most cases and only needs to be applied. Ammonia and carbon dioxide are well established and propane for mobile air conditioning is also state of the art as it is the best solution to achieve a GWP < 150 and only small quantities are needed. Larger air conditioners could follow as soon as EU regulations allow larger charges. These would still be smaller, by the way, than those in the usual propane gas cylinders for barbecues mentioned before. The technology is already being used successfully in China and India.

We are hoping that companies like Godrej and Midea will sell equipment with CE mark for propane to the European market. As we can see, besides our own wish for propane air conditioning, there is a growing demand. And last but not least I’m wishing more installers will become familiar with the technology and get the necessary training.

Please complete the sentence

The biggest obstacles for Green Cooling at the moment are…
disadvantages in the regulations and false facts about the use of ammonia, carbon dioxide and hydrocarbons spread by the chemical industry to secure the investment in their expensive synthetic refrigerants that they want to continue selling.

I love my job because…
it is versatile and never gets boring.

There should be more women in refrigeration and air conditioning because…
they prefer to judge according to facts rather than their ego.

Did you ever feel you were at a disadvantage as a woman in the cooling sector?
I never had an authority or acceptance problem. As long as someone is capable and does a good job, it's not an issue.

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