A manager in a suit operates a tablet in a production hall, with machines blurred in the background.

For Business Leaders: Strategically Managing Energy and Cost Efficiency

Rising energy prices, increasing regulatory pressure, and limited investment leeway require clear business decisions today.
ONI supports executives of energy-intensive companies in leveraging energy efficiency as a strategic business lever—with concrete, verifiable savings potential, well-founded business cases, and solutions that can be strategically justified. This enables you to secure sustainable EBIT, liquidity, and competitiveness without getting bogged down in technical details.

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A plant manager in a hard hat and high-visibility vest works on a laptop in a production hall.

For Plant Managers: Optimize Processes, Ensure Stable Operations

Rising energy costs, high production pressure, and limited personnel resources demand solutions that work reliably in day-to-day operations. ONI helps plant managers safely integrate energy efficiency measures into existing workflows—with measurable savings, stable processes, and solutions that don’t slow down ongoing operations. This way, you increase efficiency, supply reliability, and plant availability without adding complexity.

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Portrait photo of Wolfgang Oehm, founder of ONI-Wärmetrafo, in a dark blue suit.

The ONI Success Story: From a Garage to a Global Market Leader

Founded in the early 1980s, ONI has been writing a success story for four decades now. From very humble beginnings, the company has grown into a business with more than 485 employees, earning worldwide recognition and awards not only for its energy-saving system solutions but also for its corporate performance. Today, more than 6,000 customers in over 70 countries worldwide—ranging from small and medium-sized businesses to global corporations—rely on energy-saving technology from ONI.

About the History

Energy Optimizer

Annual savings for ONI customers:

Heating energy

11.316.611
MWh

Electricity

6.497.872
MWh

Emissions reduction

5.995.226
tCO2

Your project from a single source

ONI Solution Overview

Cooling

Industrial cooling ensures that heat is reliably removed from processes, machines, and systems—ensuring quality, cycle times, and operational safety. ONI designs and implements customized systems for this purpose.

About cooling

Heating

ONI implements heating concepts primarily through heat recovery, high-performance hydraulics with industrial pumps, and—depending on your needs—combined heat and power (CHP) units as an efficient solution for both electricity and heat. This results in a customized industrial hall heating system tailored to your specific industrial application and requirements.

About Heating

Ventilation

With modern industrial ventilation technology, you lay the foundation for clean air, stable processes, and safe industrial operations. 

About Ventilation

All Solutions

Everything from a single source at a glance.

Heating
Cooling
Ventilation
Energy Supply & Storage
System Technology & Plant Optimization

360° interior view of an ONI container refrigeration unit

Key Topics

Your ONI Contact

We’re happy to answer your questions!

+49 2266 4748-0
info@oni.de

All Locations

Portrait of a smiling ONI contact person with arms crossed in a production hall.

Industry Overview

We are already active in these industries

Your benefits

Why Choose ONI

Comprehensive
system solutions


ISO-certified

Assistance
with applications

24/7 service
worldwide


Over 40 years of experience

Patented
efficiency technologies

Financial stability
through CrefoZert

International
recognition

Proven Excellence

References & Testimonials

Bernhard Gell | Project Manager | HILTI

“For over 20 years, ONI has been responsible for the installation and technical support of refrigeration systems at Hilti Kunststofftechnik GmbH. During this time, our experience working with them has been entirely positive, both in terms of their consulting services and the quality of their work and technical support.”

Secure packaging, designed with sustainability in mind.

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With a strong focus on quality and cost efficiency, the Ansbach-based closure specialist Heinlein Plastik-Technik has invested in its energy and…

Read more

 

Success through quality, efficiency, and hygiene standards

Read more

 

C. Hübner has implemented a system for reusing energy once it has been utilized, ensuring a high level of supply reliability, along with a heating…

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Precision and efficiency for innovative products.

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Innovative, energy-efficient, and successful worldwide

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Bergi-Plast GmbH, based in Saxon Switzerland, has partnered with systems specialist ONI to implement a comprehensive, optimized supply concept.

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Secure packaging, designed with sustainability in mind.

Read more

 

Bernhard Gell | Project Manager | HILTI

“For over 20 years, ONI has been responsible for the installation and technical support of refrigeration systems at Hilti Kunststofftechnik GmbH. During this time, our experience working with them has been entirely positive, both in terms of their consulting services and the quality of their work and technical support.”

Secure packaging, designed with sustainability in mind.

Read more

 

Success through quality, efficiency, and hygiene standards

Read more

 

C. Hübner has implemented a system for reusing energy once it has been utilized, ensuring a high level of supply reliability, along with a heating…

Read more

 

Secure packaging, designed with sustainability in mind.

Read more

 

With a strong focus on quality and cost efficiency, the Ansbach-based closure specialist Heinlein Plastik-Technik has invested in its energy and…

Read more

 

Success through quality, efficiency, and hygiene standards

Read more

 

Minimizing Energy Consumption as a Competitive Advantage

Energy management at PET blow molding and injection molding company Obeck Verpackungen.

Read more

 

Given the German government’s ambitious goal of reducing CO2 emissions by 40% by 2020 compared to 1990 levels, energy-intensive businesses in…

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ZKW Investing to save. Strategically planned energy savings

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With a strong focus on quality and cost efficiency, the Ansbach-based closure specialist Heinlein Plastik-Technik has invested in its energy and…

Read more

 

Kunststoff- und Elektrotechnik GmbH uses refrigeration systems from ONI-Wärmetrafo GmbH at its production site in Mönchweiler.

Read more

 

Innovative, energy-efficient, and successful worldwide

Read more

 

Minimizing Energy Consumption as a Competitive Advantage

Energy management at PET blow molding and injection molding company Obeck Verpackungen.

Read more

 

Our customers

These customers already trust us

AEG logo
AFK logo
Ahle Federn logo
Airbus logo
AKG logo
Akro-Plastic logo
Atlas Copco logo
Audi logo
Aurubis logo
Balda AG logo
Barlog plastics logo
Battenfeld logo
Behr Service logo
Bergi-Plast logo
Bilstein logo
BMW logo
Borscheid + Wenig logo
Bortec logo
BP logo
Brose logo
Bruder logo
Bosch und Siemens Hausgeräte (BSH) logo
Badische Stahlwerke (BSW) logo
BWP logo
Coko logo
Cotarko logo
Degussa logo
Delphi logo
Deutz logo
Disc-Pac logo
Dörrenberg Edelstahl logo
Dura Automotive Systems logo
Drahtwerk Köln (DWK) logo
Dynamit Nobel logo
Eaton logo
EDAG logo
Ehlebracht AG logo
EKT Kunststoff logo
Elotherm (SMS group) logo
EMA Induction Technology logo
EnBW logo
Engel logo
Ensinger logo
Euroguss logo
Evonik logo
Faurecia logo
FEP logo
Ferromatik Milacron logo
Flender logo
Flühs Drehtechnik logo
Ford logo
Fries logo
Fronberg logo
Gambro logo
Gardena logo
Gealan logo
Georg Fischer logo
Gerodur logo
Gizeh logo
Carl Gommann Härterei logo
Hager logo
Hansgrohe logo
HBW-Gubesch Kunststoff-Engineering logo
Heismann Drehtechnik logo
Hella logo
Heyco logo
Hilti logo
HKM logo
HTP logo
Hünersdorff logo
Husky logo
International Automotive Components (IAC) logo
Ineos logo
ITW Automotive logo
Johnson Controls logo
Jokey logo
Joma-Polytec logo
Kärcher logo
Kautex logo
Key Plastics logo
Kirchhoff Automotive logo
Kuhn Edelstahl logo
KMS logo
Korinex logo
KraussMaffei logo
Kröger logo
Kunststofftechnik Backhaus logo
KTW Group logo
Lear logo
Leoni logo
Liebherr logo
Linpac logo
LKH Kunststoffwerk logo
Lüdecke logo
Lumberg logo
Magna logo
Mapa logo
Menshen logo
Mercedes-Benz logo
Mitsubishi Paper Mills logo
Möller logo
Möller Tech (MöllerGroup) logo
Montaplast logo
Müller Technik – Präzision in Kunststoff logo
Multiform logo
Otto Fuchs logo
Otto logo
Perstorp logo
Philips logo
Phoenix Contact logo
Plastitec logo
Plaston Group logo
Plastromayer logo
Playmobil logo
Pollmann logo
Polymer-Chemie logo
Polytec Group logo
ARaymond logo
Reese Härterei logo
Renolit logo
Rexam logo
Riegler Kunststoff- und Medizintechnik logo
Rittal logo
Röchling Gruppe logo
Rosti logo
Rotho logo
RPC logo
Sachs logo
Salzgitter Hydroforming logo
Scanex logo
Schaegner logo
Schaltbau logo
Schmidt + Clemens logo
Schneegans logo
Schoeller Allibert logo
Schuler logo
Simona logo
SLM Kunststofftechnik logo
SMP (Samvardhana Motherson Peguform) logo
Sonoco Plastics logo
Schoeller logo
Sprint Metall logo
Stauff logo
Stehr logo
Stöckli logo
Streng Plastic logo
Sulo logo
TDK logo
ThyssenKrupp logo
Ticona logo
TPP logo
Trisa of Switzerland logo
Tupperware logo
Veka logo
Vema logo
Vetter logo
Voss logo
Volkswagen logo
Warsteiner logo
Webasto logo
Weber logo
Weidmüller logo
Wilden Gerresheimer logo
Wirthwein logo
Ypsomed logo
ZF logo
Zittauer Kunststoff (zik) logo
ZKW logo

About ONI

Responsibility for the Future

ONI operates based on a clear philosophy: taking responsibility for the future—together with our customers. At the core of this is the conviction that economy and ecology are not mutually exclusive. That is why ONI develops system solutions that require less and less energy, counteract rising energy costs, and simultaneously significantly reduce the environmental footprint.

Sustainability is not just a buzzword here, but a guiding principle for development, growth, and service: From the initial idea to implementation, energy-efficient systems and services are delivered from a single source—with the goal of ensuring a sound return on investment and minimizing environmental impact.

The impact is measurable: Collectively, ONI customers reduce the environmental burden by more than 5.5 million tons of CO₂ annually. Complemented by reliable, comprehensive service even after delivery, our vision and mission evolve into long-term partnerships—for more efficient processes and a more sustainable industry worldwide.

About Mission & Vision

Careers at ONI

Join our team

"Our success is the result of outstanding teamwork and a product and service portfolio that is perfectly tailored to market needs. We are a strong team […]. That is why, for me, our employees are just as important as our customers!" 

(Wolfgang Oehm, company founder and managing partner)

Discover your opportunities. At ONI, every day brings the chance to learn, grow, and share in others’ success—if you choose to. Seize this opportunity: Take the next step with us.

View open positions

Stronger Together

Network partners of ONI-Wärmetrafo GmbH

Kunststoff-Cluster (KC) logo
Kunststoff-Netzwerk Franken (KNF) logo
Kompetenznetz Mittelstand logo
Kunststoff-Initiative Oberberg (KIO) logo
Kunststoffland NRW e. V. logo
Kunststoff-Zentrum Leipzig (KUZ) logo
Kunststoff-Verbund Brandenburg Berlin (KUVBB) logo
SKZ – Das Kunststoff-Zentrum logo
Polysax Bildungszentrum Kunststoffe logo

ONI on the Road

Our trade show dates

05/19/2026    05/22/2026
06/09/2026    06/11/2026
KUTENO / Booth 20-F25
Bad Salzuflen
09/16/2026    09/17/2026
Plastics Trade Show / Booth 306
NL-'s-Hertogenbosch