ISO-class air cannot be compromised
Semiconductor fabs move enormous volumes of conditioned air to hold ISO-class cleanliness, then exhaust much of it. That exhaust can carry trace chemicals and particulates that must never return to the cleanroom, which rules out any recovery device with stream carry-over.
The safe recovery design
A sensible plate heat exchanger recovers heat from fab exhaust to pre-condition incoming make-up air, with a solid partition guaranteeing zero cross-contamination. Only temperature moves; moisture and contaminants stay in the exhaust.
Where the savings land
Fab make-up-air heating and cooling is a major load. Recovering even part of it cuts utility cost and carbon intensity while keeping the cleanroom within specification.
What to watch
Verify chemical compatibility of the plate material with exhaust constituents, and provide drain and purge provisions for any condensate.