The project consisted of a new air-handling unit above a Class 100 cleanroom. The AHU served three cleanroom zones with reheat. Make-up air for bay pressurization control was provided to the new AHU by two existing 100% outside air units.
- GBA was initially brought into the project and conducted a thorough design review, but the project then went through an extensive redesign and GBA was only brought in again at the end of the design. GBA still provided 171 design review comments and also was able to conduct three BIM reviews on coordination and maintenance accessibility. Seventy-three construction issues were identified during functional testing.
- The system operates as constant volume, and there was no isolation between the zones, so no zone setbacks could be implemented unless at the system level. The owner could choose a critical zone for temperature and pressure control, but was limited by the pressure relationship to the existing cleanroom access aisle. The cleanroom exhaust was also not completed during the construction phase, so while the sequence of operation was tested, the cleanroom was left in a limited operation condition to reduce over-pressurization of the space.
- Another issue identified during construction was that the AHU was designed for 50°F entering chilled water temperature, but the building operators set the temperature at 59°F. This could result in the site needing to lower the chilled water setpoint if the cleanroom loads required additional cooling.
- A final systems manual was issued to ANL, providing a detailed system description as well as all the design review comments, pre-functional checklists and functional performance tests, and final project results.
- Overall, the cleanroom expansion project was a complex design and required close coordination from the commissioning provider, controls and test and balance contractor, and site team.