A pharmaceutical company that produces drugs in cleanroom asked Eolios Ingénierie to provide information on cleanroom conditions when reducing the ventilation rate of sterile air.

The ultimate goal was to reduce the throughput, and thus the energy costs (cooling, heating and energy of the fans), while the conditions of the clean room had to remain within the given limit values.

EOLIOS modeled the clean room including internal sources of pollution. After that, two phases were considered: “in operation” and “at rest”.

A steady-state calculation was carried out for the “in operation” phase , during which a continuous flow of pollution was produced. A time dependent calculation was made for the “at rest” phase, which determined the time required to ventilate a certain amount of pollution. Both phases were considered at the current ventilation rate and two lower rates. For validation, the results of the current situation were compared to the measurements of the actual recovery time. Calculations at lower flow rates have shown us that the required quality level can be guaranteed when the flow rate is reduced to a certain level.