Positive Air Pressure Cleanrooms

Cleanrooms are classified into 2 categories, positive and negative air pressure cleanroom HVAC ( Heating, Ventilating and Air Conditioning ) systems. Positive air pressure cleanrooms systems are normally used for Electronics, Aerospace, Optics, Military and Defense applications, and Research, etc., where the air escaping from doors, ceilings, or walls, due to the positive air pressure, is not hazardous and not creating safety or health concerns. The amount of particulate cleanliness required determines the design concept, amount of air filtration, CFM (cubic feet per minute) and total HVAC.

Positive Air Pressure Cleanrooms normally operate in an air pressure range of 0.02 in. to 0.2 in water column (H20). Positive air pressure means the cleanroom or rooms are "pumped up” with more filtered air then the surrounding space outside the cleanroom(s). There are different cascading levels of positive air pressure from the cleanest rooms at the highest pressure down to the gown room/or airlock room.

A) Electronics, Aerospace, Optics, Research, Military, Defense, etc. This style of cleanroom design normally involves products research, manufacturing, or repair & calibration that does not normally require the room surfaces, and equipment to be sanitized or sterilized to eliminate microbial contamination.

B) Pharmaceutical Production - FDA Validatable

This style of cleanroom requires additional details of construction to allow wet chemical sterilization of surfaces, equipment, and increased positive air pressure gradients, etc. FDA validatable cleanrooms require additional capability to validate and certify control and monitor equipment and procedures to either manually or automatically record permanent written records or data- logging to match manufactured batches of product with the cleanroom facility performance.

C) Medical Production - FDA Validatable

This style cleanroom is similar to the pharmaceutical style. The product requirements for particulate cleanliness and sterility will determine specifications for finishes, controls, and manual and automatic documentation.

D) Pharmaceutical / Medical Research
This style of cleanroom is similar to the requirements for pharmaceutical or medical products cleanrooms except that there is usually no requirement for any FDA validatable features.