Cleanroom Design

As a general rule-of-thumb, the pressure within a clean room should be slightly higher than atmospheric pressure to prevent dust from being blown in.

Does this help

You can find the information you're looking for in the ISO 14644-X series of standards, available from several document delivery services or from IEST.

As jlsoucey said, ISO 14644 standards should be taken into account in regard to the cleanroom technology.

ISO 14644-1 deals with classification and ISO 14644-4 is specific to design, construction and start-up of cleanrooms. ISO 14644-3 is about Test Methods.

From your message, I take that you are not familiar with cleanrooms so I advice you to learn about cleanrooms and, if possible, seek help from companies with a proven background in this field.

Designing and building cleanrooms requires a great deal of knowledge and experience and this is not to be taken lightly.

As to the differential pressure, the usual practice is having 10 - 15 Pascal across different classification rooms.

Anyway, I would like to know what is the purpose of the cleanrooms. There are different criteria and requirements for different applications of the cleanrooms, and if they will be used to manufacture medicines, in addition to the ISO standards, you should take into account the cGMPs issued by the local health authority.

I would also like to know if you are acquainted with HVAC. Are you a member of ASHRAE?

If you can provide more info, I will give more tips.

Best regards,

Mario