Clean/Dry Rooms
Clean/Dry Rooms
When constructing a Lithium Ion Battery Facility for Fuel Cell or Field Device use, a particular portion of the facility is required to be a dry and/or clean. Additionally several preliminary assembly steps (Case Manufacturing, Sub Assembly, and Welding) require cleanroom assembly and/or cleaning and packaging due to the need to insure the substrates do not add or contribute contamination to the process. Most notably the facilities will have the following parameters:
• Class 10,000 (ISO Class 7) to Class 1000 (ISO Class 6)
• 70 degrees F Temperature Parameters
• 2% to 10% Relative Humidity (As low as -40 degree dewpoint)
Given the above requirements there are several significant technologies, both from an engineering and construction material perspective developed for pharmaceutical and semiconductor cleanrooms and BSL (Biological Safety Level) facilities that are applied to these facilities. Hodess Construction Corp’s experience in both clean and dry room design and construction is unique, and without equal delivering combination clean/dry facilities.
Desiccant Drying capability is required to meet the needs of the dry rooms, due to the low level of humidity and dewpoint of the factory air. Integrating the requirements of a cleanroom without looking at the air systems holistically can affect the performance and cost of a combined clean/dry room dramatically.
How Does the Requirement for Cleanliness Effect a Dry Room Design Concept?
• It requires increased airflow to achieve cleanliness classification (ISO 5-7), from non cleanroom classified space.
• It creates a requirement for more return paths to get cleanliness at work surfaces.
• Dictates the requirement for ceiling mounted filtration used as final filtration versus central air handling as final filtration.
• Requires reduction of horizontal protrusions that cause particle accumulation.
• Rooms require certification by ISO 14644 requirements.
How do we design these facilities?
• Precondition make up air with cooling to minimize desiccant dryer size.
• Separate the air drying function from the cleaning function
• Extend the clean/dry envelope to incorporate the air recirculation function.
• Get the duct distribution into the envelope (buffer zone) immediately after discharge from the drier, to minimize its cost.
• Use the return side of the air system as a buffer zone for the supply air