Clean Room Hvac Design
The 4 important air conditioning design considerations for clean room system design are.
Clean room hvac design. The hvac system for cleanrooms is a specialized field requiring thorough understanding of cleanliness guidelines airflow streams room pressurization temperature humidity and filtration requirements knowledge of codes and standards specialty equipment instrumentation and control and many more details. Introducing air in a manner to prevent stagnant areas where particles could accumulate. The amount of air is different in an iso class 6 and iso class 8 cleanroom. Detailed discussions will cover airflow quantity velocity flow patterns and floor arrangement key controlling variables on cleanroom s air cleanliness air shower airlock and basic pressurization.
Clean room recirculation units simple low pressure recirculating ahu design with very low unit pressure drop units are scheduled for 3 0 tsp which includes terminal hepa dp. In these applications heat removed from the cleanroom is vented into the room outside. This means that the hvac system must be capable of conditioning more than double the air. Compounding pharmacies typically have two room types with anterooms placed between or adjacent to each room.
Based on the cleanroom size desired temperature and heat dissipated inside the cleanroom terra will configure the appropriate number of units. Standard cleanroom a c module. Commonly a cleanroom service corridor needs to be designed slightly positive or neutral pressure do not design it i n negative pressure unless a du al compartment lock is utilized. Hvac design is driven by the required cleanliness of the room iso class but also by the required temperature humidity and pressure differential.
It takes a mix of engineering skills understanding the particle generating potential of the process and experience. One important item to note is that all csp areas and anterooms are cleanrooms and require hepa filtered supply air. These conditions are dictated by the process involved in the cleanroom and the comfort of the personnel working inside the room. Identification of critical area type and placement is important to hvac design and air distribution.
The first will discuss the fundamentals of cleanrooms and hvac systems design including the classifications of cleanrooms cleanroom iso standards design and testing guidelines by ashrae and nebb particulate sources from indoor and outdoor and their impacts on cleanroom air cleanliness. Traditionally designers have used an air velocity of 0 5 m s as the standard for cleanroom design however recent research has shown that velocities as low as 0 35m s are able to maintain the correct particle count within a room again dependant on the level of particles generated by people and processes.