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Windy Moerman
Windy Moerman has been Co-CEO of the Callens Group, together with Annick Callens, since 2003. He grew with the company from within: in the early years he, like Annick, worked his way up through every department to acquaint himself with industrial processes and customer needs.
These days, he translates that broad experience into a distinctly strategic and operational role. Under the impetus of Windy and Annick, Callens grew into Belgium’s market leader. Presently, they are purposefully building on an international future for the Callens Group, with steps into the Netherlands and France for starters.
Windy Moerman believes in entrepreneurship with strong, forward-looking partners. He sees the energy transition as a unique opportunity to guide customers to sustainable, future-proof solutions.
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Annick Callens
Annick Callens is Co-CEO of the Callens Group, a role she shares with her colleague, Windy Moerman. Her entire career has revolved around Callens, the family-owned business her dad, Willy Callens, founded in 1966.
In 1996, she joined the company as a member of staff, in the hope of leading Callens one day. She started in the warehouse and the workshop where she got practical experience in Callens’s core activity. Within a few years, she had worked her way up through every department.
In 2003, Annick Callens and Windy Moerman officially took over the helm from Willy Callens as CEOs and further developed the company into a Belgian market leader.
Annick watches over the core value her dad had always held dear: customer centricity and a people-oriented policy. As custodian of the corporate culture in the long term, she makes sure that every decision harmonizes with the DNA of the Callens Group, with a specific focus on workers’ well-being.
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Kris Stappers
Kris Stappers is Chief Sales Officer at the Callens Group. Engineer by training and with extensive commercial experience under his belt, Kris focuses on the intersection of technology and business.
As CSO, Kris now steers the Callens Group’s commercial course. He works closely with managers and technical decision-makers to translate complex energy-related issues into future-oriented solutions.
Because of his background, Kris has a thorough grasp of both the technical reality production environments face and of the strategic objectives organizations pursue. He thinks along pragmatically, poses the right questions and fosters long-term collaborations.
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Henri De Nys
Henri De Nys is the COO of Callens Belgium. With a critical eye and clear perspective, he streamlines every layer of our organization.
Thanks to his experience of engineering and project management, he knows exactly which processes are crucial and where projects can be organized more efficiently. His approach is focused on structure, transparency, and removing practical obstacles so that our teams can carry out their work in optimum circumstances.
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Stefan Vercauteren
Stefan Vercauteren is the Callens Group’s Business Development Manager. In that role, he links changing market needs to technologically relevant solutions. To do so, he works closely with the Department of Technology.
Thanks to his extensive expertise in automation, process optimization and strategic account management, he is quick to identify the core challenges production facilities have to deal with. His additional specialization in energy transition and the associated CO2-emissions reduction makes Stefan more than qualified to brainstorm ambitious, yet realistic, solutions.
Based on the conviction that businesses need economic resilience, he focuses on energy flexibility. Callens’s independence ensures that we are always able to put together the most suitable solution to cater for every situation.
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Tommie Duyvejonck
Tommie Duyvejonck is HR Director at Callens. With his people and talent-oriented policy, he creates a safe and inspiring workplace for the Family of Fire.
Thanks to his targeted employer branding and recruitment strategy, Tommie allowed the Callens Group to grow from a Belgian SME into an organization with multiple branches.
His credo? People grow best when they are given the space to discover their talents, assume responsibility and step outside of their comfort zone. Give people opportunities rather than pigeonholing them, that way both they and the organization will grow apace.
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Bert De Gryse
Bert De Gryse is Department of Technology Director at the Callens Group. He oversees the Group’s research & development component.
Together with his team, he identifies emerging technologies and translates them into concrete customer applications. From e-boilers and heat pumps to sophisticated MVR solutions, each one of them known technologies, but always an exciting challenge to integrate them correctly and make them pay.
By analyzing technological innovations at an early stage and implementing them in a targeted manner, Bert helps businesses reduce their energy consumption and meet the increasingly stringent emission requirements at the same time.
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Niels Rozendaal
Niels Rozendaal is Chief Technical Officer at the Callens Group. Drawing on his background as a technology developer, he advises the group on complex and innovative projects.
Niels’ interest in flue gas treatment systems led him to found his own company, Optimum, in 2000, built around proprietary technology. Specializing in thermal oxidation systems, the company quickly established itself as a success in the market. In 2018, Niels joined forces with Callens by bringing Optimum into the group. Today, Optimum is fully integrated within Callens, and Niels leverages his expertise to support projects and initiatives across the entire organization.
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Ivo De Decker
Richard Zappeij
Richard Zappeij is Service Manager in Belgium. He has more than 30 years’ experience in industrial environments, with a strong focus on inspection, maintenance and operations.
His strength lies in business process management. Armed with that knowledge, he streamlines the service team from planning through implementation.
Richard’s clear vision of service can be felt throughout business: solid technical service is not measured by the problems we solve but by the trust we generate.
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Ellen Beernaert
As Sales Manager Service & Maintenance Belgium, Ellen Beernaert carefully listens to industry’s maintenance and service needs and addresses them with a suitable formula.
Thanks to her previous experience of planning and work preparation within the Callens Group’s maintenance division and regular contact with customers, she developed a sixth sense for underlying customer needs.
She now uses that experience to quickly lead customers to the right solution.
An interest in people, a listening ear and a keen awareness of reality: that’s how Ellen makes the difference.
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Vincent Weyne
Vincent Weyne is the Callens Group’s Business Development Director France. In that role, he supports French companies in their energy transition, with a focus on industrial decarbonization.
Exploring the international arena has been the leitmotiv of Vincent’s career. Over the past 20 years, he gained experience in both Europe and Asia, giving him a razor-sharp insight into market development.
Other than that, he facilitates the collaboration between the Belgian Callens and the recently acquired Cometi to optimally attune know-how and expertise to the needs of French industry.
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Ann Verhue
Ann Verhue is HSQE Manager at Callens. She is responsible for the company’s policies and initiatives related to health, safety, quality, and environmental management.
With a background in engineering, she began her career at Callens as a safety advisor. This combination of technical expertise and hands-on experience has given her unique insights into continuously strengthening and refining the company’s safety culture.
Today, she oversees a broader portfolio of standards and compliance requirements. For many years, she has guided Callens through the certification processes for ISO 9001, ISO 14001, and VCA**.
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Robert-Jan Zoll-Dijkema
Robert-Jan Zoll-Dijkema is the Managing Director of Jonker, the Dutch arm of the Callens Group.
Since 2011, Robert-Jan has been playing an active role in Jonker’s growth. He joined the company as a member of the planning department and worked his way up to general manager. He took over the company from the Jonker family in 2019: in doing so, he became the owner and managing director of the successful company he had been working for with unwavering drive at the age of 35.
Under his direction, Jonker evolved into a future-oriented organization, with respect for its family atmosphere and strong customer focus that put the business on the map. In 2025, Jonker joined forces with the Callens Group to seize new opportunities from a stronger base.
Robert-Jan believes in people-centered entrepreneurship which translates into Jonker’s people-oriented policy and a close involvement with customers. In addition, Robert-Jan’s vision is very much focused on the future of industrial energy and technology to provide industry with sustainable solutions for a bright future.
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Gilles Capitaine
Gilles Capitaine is Co-Managing Director of COMETI, the French subsidiary of the Callens Group, alongside Frédéric Guichet.
He began his career with Spirax Sarco, a global leader in steam and thermal energy solutions, where he held a commercial management position. There, he gained extensive experience in the industrial sector, building a strong combination of technical expertise, commercial acumen, and a deep understanding of energy-related challenges.
In 2011, Gilles and Frédéric Guichet acquired COMETI and have since successfully grown the company into a leading player in its field. As the business expanded, his role gradually evolved from day-to-day operations to broader leadership responsibilities. Today, he focuses primarily on the company’s strategic direction, financial management, and organizational development.
Firmly convinced that the energy transition presents a major opportunity for industry, Gilles is committed to driving COMETI’s long-term growth through a balanced focus on energy efficiency, decarbonization, and industrial competitiveness. At the same time, he remains dedicated to preserving the agility, technical excellence, and close customer relationships that have always been at the heart of COMETI and the Callens Group.
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