The hot exhaust air from air compressors is used to heat water for numerous applications in the automotive industry.

Sustainable heat recovery systems: Hot water applications in the automotive industry

Energy efficiency and sustainability are key drivers for the future, particularly in the automotive industry, where companies are increasingly exploring innovative solutions to minimize operating costs and reduce their environmental impact. One up-and-coming technology that is gaining increasing importance in this context is heat recovery using compressors. 

In this blog, we will take a closer look at the advantages of hot water applications enabled by these systems.

Heat recovery can significantly reduce a company’s energy consumption. During compressed air generation, a substantial portion of the energy is converted into compression heat. Instead of releasing this heat unused into the environment, it can be captured by a heat recovery system and used to heat water. This not only reduces energy costs but also ensures more efficient use of resources.

Installation of innovative heat recovery systems therefore not only saves money but also helps reduce CO₂ emissions. By minimizing the use of fossil fuels for water heating, companies can take an active role in protecting the climate.

Versatile application possibilities

The automotive industry is inherently a driver of innovation and serves as a pioneer for many technologies. It is no wonder that heat recovery is becoming an increasingly valuable asset in this sector, enabling a huge range of hot water applications as diverse as the vehicles offered by the automotive manufacturers themselves:

Preheating cleaning water:

In automotive production, large volumes of water are required for various cleaning processes. Heat recovery can be utilized to preheat this water, significantly reducing the energy consumption required for heating.

This hot water is then used to clean parts and components, effectively removing oil, grease, dirt, and other contaminants. Regular cleaning of machinery and production equipment is also essential to maintain optimal performance and product quality, as contamination can cause breakdowns or lead to product defects.

Exhaust air from a compressor heats the water for hot water applications in parts cleaning.
Efficient manufacturing: Heat recovered from air compressors is used to generate hot water, which is then used to clean automotive parts.

Surface treatment preparation:

Before painting or coating, metal surfaces must be thoroughly degreased. In these processes, hot water enhances the effectiveness of chemical cleaning agents in removing oils and grease.

Following cleaning, phosphating - a method to improve surface adhesion and corrosion resistance - is often applied, which also requires hot water.

Vehicle bodies were cleaned with the hot water generated using heat recovery.
Heat recovery systems ensure a consistent supply of hot water for thorough bodywork cleaning during production.

Process heat:

In manufacturing processes, such as injection molding, tools and molds need to be preheated to specific temperatures. Hot water is used as a highly efficient medium for temperature control in these applications.

Another application of process heat is in the use of process baths. In metalworking or surface coating, various baths often need to be heated to specific temperatures to facilitate chemical reactions. These include electroplating processes (galvanizing) and chemical processes (electroless plating).

Electroplating with hot water produced by a compressed air compressor.
Hot water, heated using recovered energy, supports the galvanizing process to ensure high-quality surface finishes.

Heating production spaces:

The exhaust heat generated by compressors can be repurposed to heat production halls or workshops, creating a comfortable working environment that enhances employee satisfaction and productivity. 

Hot water for sanitary facilities:

Heat recovery systems can also supply hot water for sanitary facilities, a critical requirement for handwashing in production areas where employees frequently handle greasy or dirty materials.

Hot water for handwashing is generated using heat recovery from a compressor.
Energy-efficient: Heat recovery systems provide hot water for handwashing, supplying the exact amount and temperature needed for maximum efficiency and convenience.

Efficient heat recovery systems from KAESER

To fully harness the potential of the generated heat energy, almost all rotary screw compressors from KAESER can be equipped with advanced heat recovery systems.

SM series rotary screw compressors (from 7.5 hp) and upwards can be equipped with plate-type heat exchanger (PTG) systems. Depending on the size of the system, the PTG heat exchanger is either integrated into the compressor or installed externally.

For water-cooled systems, integrated plate or shell-and-tube heat exchangers are available, depending on the water quality at hand.

In compressed air stations with multiple compressors or blowers, our SIGMA AIR MANAGER 4.0 compressed air management system ensures maximum efficiency at all times. This allows systems with integrated heat recovery to be specifically controlled and operated according to exhaust heat demand. Networking via the secure KAESER SIGMA NETWORK enables connection to control technology.

Investment in heat recovery systems can lead to swift returns through energy cost savings. This reduces operating expenses over the long term and improves profitability.

KAESER experts highlight the potential of heat recovery.
Exhaust air from the compressors is used to heat the water for your processes. KAESER experts are available to identify energy-saving opportunities through detailed analysis.

Current data analysis and KAESER Energy Saving System

We know what matters: Using the initial situation analysis (ADA) and the KAESER Energy Saving System (KESS), our experts can provide detailed insights into your compressed air system. This enables optimization of your compressed air supply for maximum efficiency and reliability.

Unlock the full potential of heat recovery: With our KAESER Energy Saving System (KESS), it is possible to precisely calculate the heat recoverable through hot water, depending on the operating behavior of the compressors. Your advantage: After an assessment by our experts, you will receive a personalized report detailing the potential heat recovery for your system. This provides you with a clear and tangible summary of your prospective savings.

Advantages of heat recovery at a glance

  • Energy savings: Utilizing exhaust heat reduces the need for additional energy to heat water, leading to significant cost savings.
  • Eco-friendly: Lower energy consumption helps reduce CO₂ emissions, thereby supporting sustainability goals.
  • Enhanced efficiency: Integration of heat recovery systems enhances overall production process efficiency by reducing energy demand for heat generation. 

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