Case Study – Capital Equipment operating efficiency in an Automotive Plant

Sector: Industrial Sector

Project: Capital Equipment operating efficiency in an Automotive Plant



Many manufacturing processes involve either the introduction or the removal of heat. To do this boilers or chillers are used as auxiliary systems to control the temperature of the process. If these systems are not running optimally they will use more energy than required. An example of where a temperature-controlled process is used is in the cleaning process before a vehicle body is painted. Various chemical baths are used each with a different temperature requirement.




In this case-study’s plant, three chillers provide chilled water to the pre-treatment and treatment dipping lines. The chillers are located within the fabric of the building and due to their location (on the floor above a critical part of the production line) they had never been cleaned.

A small trial project was initiated to clean one of the chillers to see if the energy consumption would be reduced. It was also necessary to place a water tight tank under the chiller to ensure no liquid could seep down onto the production line below.

Energy sensors were fitted to the unit to measure the before and after energy consumption levels. The chiller was then cleaned with a chemical wash and rinse to remove all dust and particulate. Once cleaned the energy usage of the chiller was re-measured.




The average daily cost for the week after the clean dropped to £476. This represents a 16% reduction in energy consumption for the week. However, the interesting set of information was that the drop in energy consumption during non-working hours fell from £17 an hour to £5.34 which is a 68% reduction in energy.

Energy optimisation needs to be holistic in terms of looking not only at efficient use of energy but also the performance and quality of systems. This is especially true in auxiliary systems which tend to be hidden from view.

By running a trial project such as this, it provides the evidence base of what works and what doesn’t. This knowledge can then be disseminated across the organisation and even down through the supply chain in typical Yokoten fashion.

This plant uses a ratio of the amount of reduced greenhouse gas per thousand pounds spent. Typical projects range at 2,000 eCO2kg to 4,000 eCO2kg. This project was 37,000 eCO2kg per annum.


reduction in energy consumption per week


reduction in energy during non-working hours