Discover The Key Components of Modular Cleanroom

Introduction

In an ISO Class 1 cleanroom, the Air Changes Per Hour (ACH) required are higher than 600. Pushing such high air volumes through the cleanroom components, filters, ductwork, and raised floor creates a thermal load. A significant portion of the sensible cooling capacity is utilized in removing the heat generated by Cleanroom's Fan Filter Units (FFU) and Air Handling Units (AHU). It is just one of the design nuances that manufacturers have to consider. They use Computational Fluid Dynamics (CFD) modeling to determine how particles move and create pressure gradients. The strategy significantly reduces commissioning time.

The fundamental concept around which all the cleanroom components are designed is ensuring high ACH and laminar flow. Modern cleanrooms are made using a modular approach in mind. They allow owners to scale their facilities and customize the layout. They can have laminar flow ISO 5 compliant rooms or general ISO 8 support spaces. All the components should work together to ensure particle limits, pressure gradients, and airflow uniformity under fully operational conditions.

This article will help readers understand how ISO classifications are meant through designing, maintaining, and testing each cleanroom component. It will also cover how they work together to ensure contamination free zones.

Cleanroom HVAC

The mechanical part of the cleanroom that requires careful monitoring is the Heating, ventilation, and air conditioning (HVAC) system.

Environmental Control

The first thing is to ensure that the unit replaces the complete room's air volume in a designated time as per the required ISO classification. ACH for the room is maintained at:

● ISO 8: 20-60 ACH

● ISO 5: 240-600 ACH

The clean room hvac system has makeup air units that take in fresh air from the outside. There are temperature and humidity controls with +-1 C accuracy. It removes the heat generated by workers and machinery to stay in line with GMP stability requirements. Typically, these cleanrooms have separate air handling units for fresh air and recycled air to ensure independent dehumidification and sensible cooling.

Pressure Variation and Monitoring

The key to ensuring contamination control is ensuring pressure zones. The cleaner area should have higher pressure, and the dirtiest area should have lower pressure. Typically, the difference is maintained at 0.05 to 0.15 inches of water column. It helps prevent cross-contamination between rooms.

Every pressure zone is monitored continuously using sensors that provide feedback to the centralized computer control hub. The system monitors the changing pressure and temperature to generate realtime alerts and adjusts the airflow dampers to maintain the pressure difference.

Ease of Setup and Lifecycle Efficiency

To ensure that the complete cleanroom is set up in a short time, it's important to have a module based design. All the components are modular and tested rigorously at the factory before shipment. The HVAC modular arrives ready to plug into ceiling plenums with quick connect duct interfaces. All its parts are tested to ensure pressure integrity and work flawlessly from day one.

Cleanroom Filtration

Filtration is the ultimate tool that keeps the cleanrooms free from contamination. A simple human breathing can introduce contaminants into the air, and the filtration system does all the work for their removal.

Tier Based Filtration System

There are two tiers of filters that fresh air molecules have to pass through to enter the cleanroom operating area. These are:

● Pre-filter: Air coming into the system first comes in contact with the prefilters. These typically have the Minimum Efficiency Reporting Value of 8-13 as per ASHRAE. They capture dust and debris, which can damage the expensive primary filters.

● HEPA or ULPA Filter: The final filter before the air enters the cleanroom is a High-Efficiency Particulate Air or an Ultra-Low Penetration Air filter. Their selection depends on the ISO classification for which the cleanroom is being designed. They are installed in the fan filter units (FFUs) to push clean air out in a smooth manner. For specialized applications like microchip manufacturing, they use boron-free ULPA media. They prevent ionic contamination risk.

Advanced Engineering for Control

The design of modern cleanroom air filtration systems ensures higher operations efficiency. These do not have structural dividers or aluminum separators that can restrict air flow. Instead, they use a folded design that fits 20 to 30% more filtration material into the same volume. It lowers the resistance the fan has to overcome to pass air through it.

Facilities often use modular FFU arrays with more filters in critical ones. Operators can adjust the speed to ensure the face velocity of air at that particular section. To ensure that no air bypasses the filters from the edges, they use knife edge gel seals and gasketed frames.

Testing and Predictive Maintenance

Cleanroom manufacturers perform factory testing using a DOP/PAO aerosol challenge. These ensure zero defects before it is shipped worldwide, instead of guessing the filter performance. Operators monitor the differential pressure across the filter with time and monitor trends. Increasing trends indicate ingress of contamination. It also tells about their replacement time and helps schedule maintenance.

Cleanroom Air Flow

Ensuring proper air flow is the most vital part of a cleanroom. They are rigorously designed to ensure that the clean room air flow is smooth and unidirectional.

Airflow Dynamics and Structure

We need laminar airflow with 0.3 to 0.45 m/s velocity. It acts like a broom that sweeps away contaminants during the operation. These are achieved by using ceiling-mounted FFU arrays that create a solid block of downward air (column airflow).

The system has specialized hollow walls and vents placed near the floor to ensure the contamination is taken out and there are no dead zones. Using this structure helps achieve ISO 5 compliance and 240 to 600 ACH. In non-critical support zones, the system intentionally mixes air using turbulent non-unidirectional flow. It has a higher air velocity of 0.45 to 0.55 m/s. These methods are effective in achieving ISO 7-8 compliance.

Control and Barriers

To ensure system efficiency, modern cleanrooms don't use the full air flow all the time. They have variable air volume (VAV) controls. These change the volume of air based on real time occupancy and process heat loads. To keep the cleanroom clean, every chamber is equipped with air showers and pass boxes. These have intense air blasts to ensure there is no contamination left. These air curtains have 20 to 30 m/s air velocity.

Simulation and Practical Validation

Before the cleanroom is even physically tested in the factory, engineers use computational fluid dynamics (CFD) analysis on the designed volume. Then analyze the airflow pattern mapping. Advanced models can even simulate human movement to expose hidden spots where dirty air might get trapped (hidden recirculation pockets). These are easy to miss using traditional methods.

During commissioning, the technicians use smoke visualization studies to see how the air flows practically. It helps identify subtle turbulences caused by the machinery layout. The factory validated ductwork and diffuser layouts ensure that the cleanroom air flow remains stable despite pressure changes.

Cleanroom Structural

The structure of the cleanroom is where the mechanical and airflow theories come to life. We can divide it into physical enclosure, ceiling, access management, and the testing phase.

Core Enclosure

● Wall and Ceiling: The main wall and ceiling are built using specialized multi-layered boards made with EPS, rockwool, or PU cores and metal skins. These provide incredibly smooth surfaces that do not flake or release particles.

● Surface Intersections: All potential sharp intersections of the wall where it meets the floor or ceiling are kept round. These typically have a 3 inch radius coving. It helps cover the long-term GMP audits.

● Flooring: Cleanrooms use raised floors with epoxy-coated designs and reinforcement to support heavy machinery. These can have conductive/ESD options to ensure that the entire room is grounded and sensitive components are protected against static and other charges.

● Viewing Panels: There are transparent acrylic windows strategically placed to allow outside operators to inspect the room without entering. It helps ensure contamination control.

Ceiling Systems and Transitions

The ceiling grids are modular. They can hold an air filter ceiling or have highly cleanable, walkable, pharma-grade tiles. It allows engineers to perform overhead maintenance without entering the room and prevents breaching classification.

To move items in and out without letting dirty air in, cleanrooms have integrated pass-through chambers. They are equipped with air showers and flush mounted construction to ensure there is no disturbance in air flow. These have mechanical interlocks that allow one door to open, preventing shorting of inside air with outside.

Construction and Testing

Modern cleanrooms are modular and come with prefabricated panel systems. They are locked together using tongue and groove or gasketed joints. It ensures airtightness of the room and easy setup of the facility, typically in a 1 to 3 days window. Before leaving the factory, the components of the cleanroom are stress tested to handle seismic and pressure-load situations. The rigorous factory testing ensures that the product arrives undamaged and physically sound to clear any cleanliness certifications.

Summary

A cleanroom provides a controlled environment through cleanroom hvac, filtration, airflow, and structural systems. It's vital to get the right combination to ensure durability and legal compliance. By utilizing prefabricated and modular designs, companies can improve their setup speed. The method also ensures that the factory-level quality assurance is permanently built into every single component of the cleanroom.

Ensuring operational success requires regular monitoring of pressure cascades, ACH targets, filter ratings, and seamless enclosures. Collectively, they achieve the official medical and manufacturing standards like ISO/GMP. These ensure low downtime and easy expansion.

For turnkey prefab and modular solutions, consult with the experts at SZ Pharma.Sz Pharma focuses on modular cleanroom solutions, and designs and builds cleanrooms in strict accordance with ISO 14644 and FDA/EU GMP standards. They provide rigorous inspection and global delivery options with more than a decade of experience. Feel free to contact:

● Telephone: +86-18241958031 / +86-19824886686

● Fax: 86-512-65488640

● Email: pharma@sz-pharma.com

● Whatsapp/Wechat: 008618241958031

FAQs

Q: What ACH range is typical for an ISO 7 medical clean room?

For a cleanroom to qualify for medical facilities, the ISO 7 classification is required. The HVAC system should be able to handle 60 to 90 ACH with ease. There should be enough air flow to ensure that the critical zones remain free from any external contamination or particles that can cause damage.

Q: How do modular structural panels maintain pressure integrity after shipping?

The modular structural panels come with interlocking edges and sealed rubber borders (tongue and groove or gasket joints). They lock together flawlessly, leaving no air gaps. Before shipping manufacturer subject them to stress tests to ensure there are no micro-cracks or damage that can cause contamination issues at the site. The whole system is verified for pressure integrity before delivery.

Q: Why are separate makeup and recirculation AHUs preferred in pharmaceutical applications?

It helps manage the system more efficiently. The outside air unit controls the humidity and introduces fresh air into the system. The recirculation air handling units (AHU) are focused on reducing the temperature or performing sensible cooling. These are the strict requirements of pharmaceutical applications.

Q: What testing confirms HEPA filter performance before installation?

Before the cleanroom components leave the factory, they are fully tested and validated. It includes the DOP/PAO aerosol challenge. It ensures that the filter is structurally ideal to ensure no leaks or bypassing when installed.

Q: How quickly can a portable clean room reach full operational classification?

Every component, including the HVAC, ductwork, and structural panels, is tested at the factory. They are balanced at the factory to ensure they can pass the cleanliness certifications. They can achieve full operational classification in 1 to 3 days.