From a small garage company to
the world market leader.

ONI started in the early 80s and has been a success story for three decades now. From the smallest beginnings, a company with more than 465 employees has emerged that has received worldwide recognition and awards for its energy-saving system solutions, but also for its corporate performance. Today, more than 5,800 customers in more than 72 countries around the world, from medium-sized companies to global corporations, rely on ONI's energy-saving technology.


The clientele of the family-owned company based in Lindlar in Oberberg includes well-known companies such as Airbus, Audi, BMW, Bosch-Siemens, EnBW, Gardena, Gerresheimer, Gizeh, Hilti, Jokey, Magna, Mannesmann, Mercedes, Salzgitter Industries, S+C, ThyssenKrupp, Tupperware, Warsteiner, VW and ZF.


The driving force is the company founder and managing partner Wolfgang Oehm. As a visionary, he had already recognized in the seventies the enormous importance that the topic of energy will have for all of us. As a long-standing plant manager at an injection moulding machine manufacturer and subsequently at a plastics processing company, he developed the world's first heat recovery system for plastics machines at the beginning of the 1980s.
This invention alone enables ONI customers to reduce their heating costs by up to 95%!


Oehm is not only an ingenious developer with vision, he is also regarded in the plastics industry as a pioneer and trailblazer for the use of energy-saving system technologies. Today, the product and service spectrum ranges from consulting and planning to the turnkey construction of complex, energy-optimized systems regarding cooling systems, heat recovery, machine optimization, patented tool temperature control, ventilation systems, clean-room technology and compressed air technology for a wide variety of industrial sectors.

ONI Gelände schmaler

Company foundation

1983

Company foundation

Wolfgang Oehm founds ONI-Wärmetrafo GmbH in 1983 in a large garage in Lindlar.

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New premises

1987

New premises

In Lindlar (industrial area of  Klause) new premises with approx. 500 m² floor space are rented.

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Acquisition of the commercial area

1998

Acquisition of the commercial area

A commercial area of approx. 40,000 m² with approx. 10,000 m² of usable space for production and administration is acquired. ONI uses 3,000 m² of this space.

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Expansion of the area

2004

Expansion of the area

Expansion of the production and administration area to approx. 10,000 m².

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Takeover of Rhytemper

2007

Takeover of Rhytemper

ONI acquires a majority stake in Rhytemper GmbH, a specialist for dynamic mold temperature control systems.

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New company name

2008

New company name

The new subsidiary operates under the name ONI Temperiertechnik Rhytemper GmbH and moves into new premises in Großröhrsdorf/Saxony.

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Expansion at the Lindlar site

2013

Expansion at the Lindlar site

Inauguration of a new production hall with an administration wing with a usable area of approx. 4,000 m². The total usable area thus increases to approx. 14,000 m² at the Lindlar location.

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Expansion of the base area

2014

Acquisition of further adjoining property area, whereby the total area at the Lindlar location grows to 76,000 m².

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Foundation of ONI-China

2017

Foundation of ONI-China

In early 2017, ONI Energy Saving Technology (Kunshan) Co., Ltd. is founded and settles in a commercial site in Kunshan City, Jiangsu Province, P.R. China.

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Rhytemper continues to grow

2017

Rhytemper continues to grow

Due its strong growth, ONI Temperiertechnik Rhytemper GmbH moves into new business premises on June 26th with approx. 1,350 m² of production and administration area.

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Further office space

2018

Further office space

In March 2018, a new office extension at the Lindlar location is inaugurated, reflecting the steady growth of ONI-Wärmetrafo GmbH.

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