The clean room ventilation system consumes a lot of energy, especially the fan of the ventilation system, summer cooling and dehumidification, and steam for heating and humidification in winter. Therefore, there has always been this question: Can the company close the ventilation of the room at night or when not in use to save energy?
Purification Engineering engineers generally do not recommend a complete shutdown of the ventilation system, facilities, pressure conditions, microorganisms, during which everything will be uncontrolled. This will make the subsequent measures required to restore GMP compliance to the state very complicated, because each time you have to re-confirm to achieve normal GMP compliance.
Some companies reduce the amount of ventilation and reduce the power of the ventilation system by reducing the power of the ventilation system. However, the GMP compliance status must be met before reusing the clean room, and the procedure must be verified.
This small series must be reminded:
The power of the ventilation system can only be reduced to a certain extent, because it is guaranteed that the overall limit of the clean room in the relevant case is not violated. In each case, the limits in these operating states and in the reduced power state must be defined, including the allowable minimum and maximum values. Note that the selection of the value in the reduced power mode must cause the facility to reach the GMP compliance status within the specified time prior to the start of production.
Also, it is recommended to install a separate clean room monitoring system so that the specified parameters of the clean room can be continuously monitored and recorded. In this way, the conditions of the area of interest should be monitored and recorded at any time.
When reducing fan power, care should be taken to ensure that there are no unintended effects of external interference, such as personnel entering. In this case, it is recommended to use the appropriate personnel access control. If an electronic lock system is used, access rights can be associated with the above time schedule and associated with a separate clean room monitoring system so that access authorization must meet predetermined requirements.
In principle, both states must be confirmed first and then periodically reconfirmed. In general, measurements in normal operating conditions, such as recovery time measurements in the event of complete equipment failure, must be performed. If there is a clean room monitoring system, the program is verified to be, in principle, not required – as described above – for further measurements when the operation is resumed after reducing the ventilation power. Of particular note is the procedure to restart the run, because, for example, when the direction of the airflow is short, reverse is possible.
Overall, depending on the operating mode and the shift mode, approximately 30% of energy can be saved, but it may be offset by additional investment costs.