Cleanrooms are among the most energy-intensive facilities in the pharmaceutical and biotechnology industries. This presentation explores practical strategies for improving energy efficiency in cleanroom HVAC systems without compromising contamination control or regulatory compliance. Topics include airflow optimization, advanced control systems, fan and filter selection, and recovery systems for heating and cooling. Real-world examples will demonstrate how thoughtful design and operation can significantly reduce energy consumption and carbon footprint while maintaining GMP and ISO 14644-16 requirements for cleanroom classification.