Cleanrooms and controlled environments are used for a variety of purposes, from food and drink preparation, to advanced microtechnology manufacture and surgical operations. The ability to effectively prevent contamination within these areas is heavily reliant on the performance of the HVAC system. The choice of ductwork therefore needs to be given careful consideration.
Why does Ductwork specification matter for cleanrooms?
The basic principles of a modern cleanroom are identified within ISO 14644-1:2015 which defines the space as a:
“room in which the concentration of airborne particles is controlled, and which is constructed and used in a manner to minimise the introduction, generation and retention of particles inside the room and in which other relevant parameters, e.g. temperature, humidity and pressure, are controlled as necessary”.
The standard also places cleanrooms into one of 8 classes based on the size of particles, and the number found within a cubic metre.
The ventilation system is the primary means by which both the filtration and other environmental parameters are controlled. To achieve this, High Efficiency Particulate Air (HEPA) or Ultra-Low Particulate Air (ULPA) filters are incorporated within the system. They’re also operated at an extremely high air flow rate with air changing tens or even hundreds of times per hour within the cleanroom (see CIBSE recommendations in table 2) compared with just 2 or 3 times per hour within a conventional living space.
