Cleanroom energy saving strategies
01 May 2018

Cleanroom energy saving strategies

At the onset of the project, the goals and objectives for the project were set. Energy reduction was one of them. And the owner was pursuing this goal aggressively, not just for this project but for the rest of the existing facility as part of a separate but parallel project. Efficiency targets were provided by the client to the design team that needed to be met or exceeded. It was refreshing that this client was willing to support this effort by not value engineering out energy saving features to save money and encouraging and providing a simplified path to justification and approval of approaches that reduced use and conserved energy. This client viewed energy savings beyond simple payback analysis. Some of the salient energy savings are listed below.

At the clean space level:

  • Minimize air change rate — the largest energy saver
  • Recirculate the air from the CNC zones
  • Recirculate the air from the ISO 7 space (with additional safety features added to the mechanical design due to hazardous classification of the space)
  • Implement an occupied/unoccupied mode of operation for the cleanroom (or set back mode) to depress air changes per hour even more
  • Specify doors with low leakage rates

At the facility level:

  • Low pressure drop ductwork design
  • Heat recovery of the exhaust
  • High-efficiency plant equipment (chillers, condensing boilers, cooling tower, pumps)
  • High-efficiency central air handlers (greater than 70 percent)
  • Extended media HEPA filters
  • Variable frequency drives

These measures promoted energy saving by design and reduced operating cost, and in some instances, installed cost due to reductions in the size of the mechanical infrastructure.