Key Takeaways from IEST Educon 2024: Cleanroom Design and Energy Efficiency

The IEST Educon 2024 conference provided invaluable insights into cleanroom design, particularly through the Contamination and Control Training Session titled "Fundamentals of Cleanroom Design Including Energy Efficiency Using ISO 14644-4 and 14644-16." Taught by Norman Goldschmidt of Genesis AEC, a firm specializing in life sciences facilities. The session offered practical and critical knowledge for anyone involved in the design, construction, or operation of cleanrooms. Here are the key takeaways:

1. Particulate Type and Industry-Specific Cleanroom Design

A critical takeaway from the course was understanding how different industries prioritize particulate control. In the semiconductor industry, the focus is on non-viable (inert) particles that can disrupt manufacturing processes. In contrast, life sciences facilities are concerned with viable (pathogenic) particles, such as microorganisms, that could compromise product safety. These differing concerns lead to distinct cleanroom design approaches:

• Semiconductor cleanrooms emphasize high unidirectional airflow and frequent air changes per hour (ACH) to capture and control particles.
• Life sciences cleanrooms, on the other hand, focus on creating smooth, cleanable surfaces to reduce microbial contamination and improve sanitation, while maintaining proper air filtration.

2. Energy Consumption and HVAC Systems

One of the most striking revelations was the massive energy consumption of HVAC systems in cleanroom environments. HVAC systems can account for 50-80% of the energy usage in these facilities. This makes optimizing HVAC design and technology critical for improving energy efficiency and reducing operating costs. Companies like Nortek, with their FANWALL energy-saving technology, are helping to optimize HVAC performance, which can drastically reduce energy consumption over the lifetime of the cleanroom.

3. Dilution Calculations vs. Air Changes per Hour

A common metric in cleanroom design is air changes per hour (ACH), but this course stressed that dilution calculations should play a more prominent role. The key to effective air exchange is not just the volume of air, but also how uniformly the air diffuses throughout the cleanroom. Faster, more uniform airflow increases dilution efficiency, which is essential for maintaining particle control. Therefore, it’s important to consider the volume of the cleanroom (cubic feet) when designing the air distribution system.

4. The Role of Temperature and Humidity Control

Temperature and humidity control are crucial in cleanroom settings, especially in life sciences. While maintaining comfort for personnel is important, it’s just as critical for ensuring that chemicals and materials within the cleanroom remain within their specified ranges. In life sciences, higher relative humidity (RH) can provide more moisture for microorganisms to thrive, making it essential to control RH levels for contamination prevention. On the other hand, lower RH increases the risk of electrostatic discharge (ESD), which must be mitigated through grounding, conductive materials, and ionization systems.

5. Recovery Testing and Cleanroom Certification Levels

Understanding how a cleanroom responds to disturbances is essential for maintaining its operational integrity. Recovery testing measures how quickly the cleanroom can return to its required condition after an interruption. According to Annex 1 guidelines, an optimal recovery period is between 15 to 20 minutes.

Cleanrooms can also be certified at different levels, including:

• As Built: The state of the cleanroom upon completion.
• At Rest: The cleanroom’s performance with no personnel inside.
• In Operation: The cleanroom’s performance when in use, with people present.

6. Contamination Control Strategy (CCS)

A thorough Contamination Control Strategy (CCS) is now a requirement in the latest version of Annex 1, which quotes CCS 48 times throughout the document. The CCS isn’t a new concept, but its implementation is becoming increasingly important. Essentially, a CCS is a strategy document that references existing procedures and outlines a detailed risk analysis procedure for contamination prevention, remediation, and monitoring. It ensures that contamination risks are proactively managed throughout the cleanroom’s lifecycle.

7. Cleanroom Costs and Long-Term Investment

One of the most eye-opening points discussed was the true cost of a cleanroom. While the initial cost of building the cleanroom is significant, the ongoing operational costs—particularly HVAC energy consumption—can be 10 times higher. Even more startling, the cost of personnel can be up to 100 times the cost of the cleanroom itself. This highlights the importance of investing in high-quality design and materials upfront. Cutting corners on cleanroom design can lead to significantly higher costs in the long run. Skimping on quality may lead to higher operational expenses, increased contamination risks, and ultimately, failure to meet regulatory standards.

8. The Importance of Expertise in Cleanroom Construction

Lastly, it was emphasized that not all contractors have the specialized knowledge necessary for cleanroom construction. While some may claim to have experience building cleanrooms, they may lack the expertise required to meet the unique needs of life sciences or semiconductor facilities. Poor design or construction can lead to costly mistakes, product losses, or even the failure of a startup business. Ensuring that you work with contractors who have deep knowledge of cleanroom requirements and best practices is essential to the success of any cleanroom project.

Conclusion

The Fundamentals of Cleanroom Design course provided essential insights into the intricacies of designing and operating cleanrooms. With a focus on energy efficiency, particle control, and the long-term costs of cleanroom operation, it reinforced the importance of upfront investments in quality design. The cleanroom industry is evolving, with a greater emphasis on strategies like CCS and recovery testing to ensure cleanrooms perform at the highest standards. Whether in life sciences or semiconductor manufacturing, it’s clear that careful planning, expert knowledge, and attention to detail are vital for maintaining a successful and cost-effective cleanroom operation.