Minienvironments

Cleanrooms and other types of high-tech research and manufacturing environments have a common intrinsic inefficiency: the air provided to very large spaces must be energy-intensively ventilated, space conditioned, and filtered for the benefit of processes that take place in only a small portion of the total enclosed environment. A prime example is in semiconductor wafer manufacturing, where the air supply for a large "ballroom" of say 10,000 square feet is filtered and conditioned and recirculated at a rates as high as 600 air-changes per hour, while the wafer manufacturing takes place only one relatively small area within the space.

The concept of isolating critical spaces is not new, as evidenced by glove boxes used for many decades in hazardous research or manufacturing processes. Minienvironments go by various names, including "isolators", "separative enclosures or devices", or "barriers" in microelectronics, chemical, and pharmaceutical industry, and "safety cabinets" in the biomedical and healthcare industries. Isolation is desired for protecting contamination-sensitive products or processes and/or to protect people and the environment.

The potential for energy savings is substantial, if, upon implementing a mini-environment, the ventilation and filtration standards are correspondingly relaxed in the surrounding cleanroom space. Potential non-energy benefits are also significant, including higher obtainable cleanliness levels, improved worker safety, process control, fewer product defects, lower overall construction costs, etc.

LBNL is conducting a case study, focusing on one of the promising applications: the semiconductor manufacturing sector, where particularly large amounts of energy are used in conventional cleanrooms.