For Business Leaders: Strategically Managing Energy and Cost Efficiency

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

Learn more

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 allows you to increase efficiency, supply reliability, and plant availability without adding complexity.

Learn more

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 humble beginnings, the company has grown to employ more than 485 people and has earned worldwide recognition and awards for its energy-saving system solutions as well as for its corporate performance. Today, more than 6,000 customers in over 70 countries around the world—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

Key Topics

Your ONI Contact

We’re happy to answer your questions!

+49 2266 4748-0
info@oni.de

All Locations

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.

Read more

 

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

Read more

 

Success through quality, efficiency, and hygiene standards

Read more

 

C. Hübner has implemented a system that allows for the reuse of energy once it has been used, while ensuring a high level of supply reliability, along…

Read more

 

Precision and efficiency for innovative products.

Read more

 

Innovative, energy-efficient, and successful worldwide

Read more

 

In collaboration with the systems specialist ONI, Bergi-Plast GmbH, based in Saxon Switzerland, has implemented a comprehensive, optimized supply…

Read more

 

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 that allows for the reuse of energy once it has been used, while ensuring a high level of supply reliability, along…

Read more

 

Secure packaging, designed with sustainability in mind.

Read more

 

With a strong focus on quality and cost efficiency, Heinlein Plastik-Technik, the Ansbach-based fastener specialist, 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…

Read more

 

ZKW is investing to save money. Energy savings are part of a strategic plan

Read more

 

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

Read more

 

Plastik- und Elektrotechnik GmbH uses refrigeration systems manufactured by Oni-Wärmetrafo GmbH at its production facility 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

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

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