Overdesign is one of the primary drivers of cleanroom size—and cost. While it is important to plan for production capacity growth, there is a big downside. The extra space built in to handle an anticipated increase in production takes more energy for heating, cooling, and more airflow.
Cleanrooms require high airflow change rates and can be as much as 50 times more energy intensive than the average commercial building. It may be cost effective to plan for growth with a modular design, allowing for increased space to be added only when warranted. Conversely, increased production within the same space may be accomplished by adding a shift, utilizing the same space and equipment for a larger fraction of time.
The airflow system design itself can have a large impact on energy consumption. Increasing airflow rates by 10% can require up to 30% more energy consumption by the air circulation system. A comparison of airflow systems demonstrated that an open plenum design has less air pressure drop and is more energy efficient than a ducted system.
From: Cleanrooms and Energy