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Case Study: Trial to replace belt-driven fans with EC fans

Before replacing all the belt-and-pulley fans in their data centre with new technology EC fans, the client wanted to confirm that the new fans would actually save energy and not reduce system performance.

The client asked if they could trial the new technology. A trial, providing a detailed quantitative report, would supply the evidence needed to support the business case for rolling out the technology across a number of sites. A trial would also assess any potential operational impacts from the upgrade, and would therefore reduce the risk of the project. The small expense of undertaking the trial therefore offered significant cost benefits and risk mitigation to the client.

Out Performers carried out the trial by replacing the existing fans with new EC fans in one of their computer room air conditioning (CRAC) units, and conducting a detailed study of energy use and performance before and after.

The trial consisted of:
1. An M&V plan, designed in accordance with the International Performance Measurement & Verification Protocol (IPMVP), world’s best practice for energy measurement and verification (“M&V”).
2. Installation of temporary data loggers on the existing CRAC unit, and measurement of the three existing belt-and- pulley fans’ energy use, air pressure, air temperature, and volumetric air flow over a two week period. As the fans were run at 100% all the time, and the chilled water outlet was also run at 100%, there was little variability in the load.
3. When the old fans were removed and replaced by the new EC fans in their pre-fabricated metal arrangements, our data logging and analysis confirmed energy savings of 29.8%.


  • Energy savings: 29.8%*
  • Maintenance savings (no belt!): providing a further 15%-20% saving
  • Successful trial – the EC fan retrofit has been extended to other CRAC units on site, with a view to a national roll-out to more than 15 sites.

* The energy savings were calculated following IPMVP guidelines, using rigorous methodologies with lower confidence factors and the most conservative assumptions. The client’s electricity tariff rate was also below average, due to the size of their operations, and we did not take into consideration any increases in electricity costs over the life of the project (10 years). We would therefore expect higher returns for those clients with moderate to high electricity tariffs, or if electricity rates were to increase.

For more information see our website, or phone Phil Goodfellow on 0452 410 652.