How much air change for class 100 cleanroom?

How Much Air Change for Class 100 Cleanroom?

In a Class 100 Cleanroom, maintaining air quality is essential for processes sensitive to contamination. According to the International Organization for Standardization (ISO 14644-1), a Class 100 cleanroom allows for a maximum of 100 particles of size 0.5 micrometers or larger per cubic foot of air. 

Achieving this standard requires a precise air change rate, which is typically set between 300 to 600 air changes per hour (ACH). This means that the air in the cleanroom is completely replaced 300 to 600 times each hour to ensure the removal of airborne contaminants.

The air change rate in cleanrooms varies based on volume, activities, and personnel. For instance, a 1,000 cubic feet cleanroom needing 600 ACH requires 600,000 cubic feet per hour to effectively dilute contaminants from personnel and equipment.

To achieve necessary air change rates, cleanrooms must use HEPA or ULPA filters, which remove 99.97% of 0.3-micrometer particles. Continuous recirculation and proper airflow patterns are crucial to prevent dead zones where contaminants can accumulate.

Temperature and humidity control are also vital. A Class 100 cleanroom is typically maintained at 20°C to 24°C and 30% to 60% relative humidity, protecting sensitive products while ensuring a comfortable working environment for personnel.

Relevant Standards and Guidelines

• iso 14644-1: Cleanrooms and Controlled Environments - Part 1: Classification of Air Cleanliness.

• Federal Standard 209E: Cleanroom Standards for Airborne Particulate Cleanliness.

• ASHRAE 170: Ventilation of Health Care Facilities.

What are the air change requirements for a cleanroom?

The air change requirements for a cleanroom vary significantly based on its classification, which directly impacts the cleanliness standards necessary for specific industrial processes. For instance, a Class 100 cleanroom typically requires between 300 to 600 air changes per hour (ACH) to maintain acceptable particle levels. 

The precise rate also depends on the activities conducted within the cleanroom, including the number of personnel, the equipment in use, and the specific processes being performed. Higher personnel counts and more complex operations necessitate greater air changes to maintain cleanliness. Ultimately, meeting these air change requirements is fundamental to ensuring compliance with international standards, protecting sensitive products, and minimizing contamination risks.

How much air does a cleanroom need?

1. Defining Air Volume

The air volume required for a cleanroom is typically calculated based on its dimensions and the desired air change rate. For example, a cleanroom measuring 1,000 cubic feet and requiring 600 air changes per hour needs to circulate 600,000 cubic feet of air per hour (CFH).

2. Flow Rate Calculation

To determine the necessary flow rate, the formula used is:

Therefore, for a 1,000 cubic foot cleanroom requiring 600 ACH, the required flow rate would be 10,000 cubic feet per minute (CFM).

3. Filtration Systems

Cleanrooms require HEPA or ULPA filters to achieve the necessary air quality. HEPA filters are designed to capture 99.97% of particles that are 0.3 micrometers, critical for maintaining Class 100 standards.

4. Air Balancing

Proper airflow distribution is essential to prevent areas with stagnant air, where contaminants could accumulate. Air balancing ensures that all areas of the cleanroom receive adequate and uniform airflow.

5. Continuous Monitoring

It’s important to continuously monitor airflow and particle counts to maintain compliance with cleanliness standards. Adjustments to airflow may be necessary based on changes in personnel, equipment use, orenvironmental conditions.

6. Maintenance of HVAC Systems

Regular maintenance of heating, ventilation, and air conditioning (HVAC) systems is crucial to ensure that they operate efficiently and maintain the necessary air flow and cleanliness levels. This includes replacing filters, checking for leaks, and cleaning ductwork.

7. Impact of External Factors

Factors such as building layout, doors opening and closing, and the introduction of materials can affect air flow and cleanliness levels. Therefore, implementing protocols for material transfer and personnel entry is vital to minimize contamination risks.

What are the specs for Class 100 cleanroom?

A Class 100 cleanroom adheres to stringent specifications to maintain a controlled environment crucial for sensitive processes. According to ISO 14644-1, a Class 100 cleanroom allows no more than 100 particles of size 0.5 micrometers or larger per cubic foot of air. 

Temperature and humidity control are also vital specifications for a Class 100 cleanroom. The recommended temperature range is generally between 20°C to 24°C (68°F to 75°F), with relative humidity maintained between 30% to 60%. These parameters not only protect sensitive equipment and materials but also enhance the comfort of personnel working within the cleanroom, enabling optimal productivity.

The air change rate in a Class 100 cleanroom typically ranges from 300 to 600 air changes per hour (ACH). This high rate of air change is essential for removing airborne contaminants generated by personnel and equipment. The cleanroom must be equipped with a reliable HVAC system that can manage these air changes while maintaining the desired temperature and humidity levels. 

What is Class 100 air quality?

Class 100 air quality is defined by specific particle concentration limits, primarily focusing on the allowable number of airborne particles. According to ISO 14644-1, a Class 100 cleanroom must not exceed 100 particles of size 0.5 micrometers or larger per cubic foot of air. This stringent requirement ensures that the environment is suitable for processes that are sensitive to contamination, such as Semiconductor manufacturing and pharmaceutical production.

Particle Count Monitoring

To maintain Class 100 air quality, continuous monitoring of particle counts is essential. This is typically done using laser particle counters that can provide real-time data on the number and size of particles present in the air. Regular sampling and monitoring help in identifying trends and potential contamination sources.

Air Filtration Efficiency

The use of HEPA filters is a critical component in achieving and maintaining Class 100 air quality. These filters must be regularly inspected and replaced to maintain their efficiency. In some cases, ULPA filters may be used for even stricter environments. The effectiveness of these filtration systems not only affects particle counts but also influences the overall air quality within the cleanroom.

Impact of Personnel and Equipment

The activities carried out within a Class 100 cleanroom greatly influence air quality. Personnel, equipment, and materials can introduce contaminants, thus necessitating strict protocols for gowning and equipment handling. Implementing cleanroom best practices is essential for minimizing particle generation and maintaining compliance with air quality standards.

What is the difference between Class 10 and Class 100 cleanroom?

Cleanrooms are controlled environments designed to minimize the introduction, generation, and retention of airborne particles. They are classified based on the maximum allowable particle count per cubic meter of air. The two common classifications are Class 10 and Class 100, which differ significantly in cleanliness levels, applications, and operational requirements.

1. Cleanliness Levels

Class 10 cleanrooms allow a maximum of 10 particles per cubic meter for particles sized 0.5 micrometers and larger. In contrast, Class 100 Cleanrooms permit up to 100 particles per cubic meter for the same size range. This means that Class 10 cleanrooms are ten times cleaner than Class 100 Cleanrooms, making them suitable for more sensitive operations.

2. Applications

Class 10 cleanrooms are typically used in industries where the highest level of cleanliness is critical, such as semiconductor manufacturing, biotechnology, and pharmaceuticals. These environments are essential for processes that are highly sensitive to contamination. 

3. Operational Requirements

To maintain the required cleanliness level, Class 10 cleanrooms have stricter operational protocols. This includes more advanced air filtration systems, controlled airflow, and stringent gowning procedures. Class 100 cleanrooms, although still requiring cleanliness measures, have slightly less rigorous protocols, allowing for a broader range of operational flexibility.

4. Cost Implications

The cost of constructing and maintaining a Class 10 cleanroom is generally higher than that of a Class 100 cleanroom due to the need for more sophisticated technology and stricter operational protocols. 

This includes advanced HEPA or ULPA filters, more extensive airflow management systems, and increased monitoring and maintenance efforts.

How to Reduce Particle Count in a Clean Room

Reducing particle count in a cleanroom requires a multifaceted approach. Key measures include using HEPA or ULPA filters, controlling airflow to minimize turbulence, enforcing strict gowning procedures, and thoroughly cleaning equipment and surfaces before entry. Continuous monitoring ensures compliance with cleanliness standards.