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.










