Overview
After 3M Pharmaceuticals commenced construction on a new clean room, which included new inhalation fill line equipment, it contracted P2S to design the MEP infrastructure for independent desiccant dehumidification air handling system. This system would supply dry air inside the equipment enclosure so that air supplied to the inhalation fill head would be delivered at 5% humidity.
Challenge
3M was challenged by moisture negatively affecting an existing cold fill process for one of its products. For the inhalation fill equipment in the new clean room 3M wanted to provide the new equipment enclosure with supply air at 5% humidity and positively pressurize it to reduce moisture infiltration from the clean room.
To supply this enclosure accordingly, P2S designed an independent desiccant dehumidification air-handling unit (AHU) along with an exhaust system. This would pull heat from different sections of the enclosure while the exhaust system would exhaust a water bath.
Because the design team worked on the project the during construction of the new clean room, it required a combined team effort between P2S and the 3M project engineers, resident engineers, construction site coordinators, field service teams and the contracting construction team.
Action
The desiccant dehumidification AHU design consists of a desiccant wheel which removes moisture from the process return air and the reactivation (heated) air stream in counterflow removes the moisture and discharges it outside. Features of the desiccant dehumidification design are 65% filtration, a pre-cooling coil, and a supply fan on variable frequency drive on the process air into the desiccant wheel. The AHU has face and bypass dampers around the desiccant wheel for energy savings with the humidity control.
Downstream of the wheel, the AHU has 95% filtration, a sensible-only post-cooling coil, ultra-violet lights, and an airflow monitoring station. Working closely with 3M resident engineers, P2S was able to reduce energy load, increase filter life and reduce wheel maintenance by providing make-up air from a conditioned space.
P2S designed the supply and exhaust duct routing inside the enclosure, as well as return air from the room, and exhaust fans on the roof. Airflow schematics provided by P2S balanced the supply, return and exhaust air flows in the equipment enclosure and in the new clean room with its air handler. P2S also provided water softening equipment and piping to serve the humidifiers and the water bath in the new clean room.
Results
To provide a comprehensive solution for this cold fill equipment enclosure, P2S engineers worked closely with 3M engineers and project managers, the design consultants and manufacturers. The desiccant dehumidification AHU solution maintains the proper environment inside the equipment enclosure making for a more efficient process.
The combined team effort for this complicated retrofit project is another example of how P2S partners and works closely with its client to successfully complete a project. The partnership on this project, between P2S and 3M project engineers, resident engineers, construction site coordinators, field service teams and the contracting construction team also created a platform for high-quality design and construction standards.
