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Energy efficiency measures - Industrial - Fans - Variable speed / United Kingdom

Case study assignment

Four electric motor-driven fans run at full speed to extract dust from a flour milling plant. Airflow is controlled by varying the position of dampers in the inlet ducts.

Base case
  • Motors are 75 kW, premium efficiency
  • Fans are variable flow and operate 7,750 h/y
  • Two fans operate at less than 50% capacity and two operate in the high flow range
  • Load factor 95%
  • Electricity rate is £0.043/kWh
Proposed case
  • Install variable speed drive on each motor
  • Cost for improvements is £13,000 per fan-motor unit
Prepare a RETScreen study, documenting any assumptions that you are required to make, and report on the significant conclusions from this analysis.

Solution

The worked-out solution is the data file selected from within the RETScreen Project Database. The user automatically downloads the Project Database file while downloading the RETScreen software.

Similar project

At a flour mill in Manchester, UK, four dust extraction fans were fitted with variable speed drive to replace the less efficient damper controlled airflow. Savings were significant.

Real project (6.97 MB)