How to quickly build a negative pressure Modular Cleanroom

What is a negative pressure clean room?

A negative pressure cleanroom is when the air pressure inside the room is lower than the air pressure outside the room. A negative-pressure cleanroom requires a low-pressure containment area with externally exhausted air. Slightly negative pressure ensures that harmful gases, noxious odors, and toxic compounds cannot spread to parallel areas. This means that when the door is opened, potentially contaminated air or other dangerous particles from inside the room will not flow outside into non-contaminated areas.

What is the difference between positive and negative pressure clean rooms?

Negative airflow and positive air flow are critical concepts in cleanroom design, each serving different purposes based on the contamination control needs of the environment. Ordinarily, negative air pressure isolation rooms are used as prevention rooms, while positive air pressure isolation rooms are used for protection. Therefore, negative air pressure keeps pathogens in, and positive air pressure is intended to keep pathogens out.

Negative Pressure Cleanroom

1. Definition:
   In a negative pressure environment, the air pressure inside the cleanroom is lower than the air pressure outside. This is achieved by exhausting more air from the cleanroom than is supplied, creating a vacuum effect.
2. Applications:
   Used in Containment Areas environments where it is essential to prevent contaminants from escaping the room, such as:
   • Biosafety laboratories (e.g., BSL-3, BSL-4, handling pathogens)
   • Pharmaceutical manufacturing involving hazardous substances
   • Hospital isolation rooms (e.g., tuberculosis wards)
3. Advantages:
   • Containment: Prevents harmful particles, biological agents, or chemical vapors from escaping the cleanroom, thereby protecting the external environment and personnel outside.
   • Safety: Essential for working with biohazards or toxic chemicals where containment is critical.
4. Disadvantages:
   • Cross-Contamination Risk: Ingress of contaminants from adjacent areas if not properly controlled.
   • Complex HVAC Systems: Requires careful balancing of airflows and pressure differentials, making the HVAC system more complex and potentially more expensive.

Positive Pressure Cleanroom

1. Definition:
   In a positive-pressure environment, the air pressure inside the cleanroom is higher than the air pressure outside. This is achieved by supplying more air to the cleanroom than is exhausted, pushing air out through any openings.
2. Applications:
   Used in Protection Areas environments where it is crucial to keep contaminants from entering the room, such as:
   • Semiconductor manufacturing
   • Pharmaceutical production (especially in areas requiring sterile conditions)
   • Medical device manufacturing
3. Advantages:
   • Contamination Prevention: Prevents contaminants from entering the cleanroom, ensuring a sterile or clean environment.
   • Product Protection: Ideal for manufacturing processes that require ultra-clean conditions to prevent product contamination.
4. Disadvantages:
   • Energy Use: Maintaining positive pressure can be energy-intensive due to the constant supply of filtered air.
   • Complexity in Multi-Zone Facilities: Managing different pressure zones within a facility requires careful design and balance.

Key Components in Both Types of Cleanrooms

1. HEPA Filtration: HEPA Filters Used to filter incoming and outgoing air to ensure that the air is free from contaminants.
2. Air Supply: In positive air flow cleanrooms, air supply is greater to maintain higher pressure. Refered to as Air Handling Unit (AHU)
3. Air Exhaust: In negative air flow cleanrooms, air exhaust is greater to maintain lower pressure. Refered to as Exhaust Fans
4. Pressure Monitoring Systems: Continuously monitor the pressure differential to ensure proper operation.
5. Regulatory Requirements:Follow industry-specific regulations and standards (e.g., ISO 14644, GMP guidelines) which may dictate the type of airflow required.

How to create a negative pressure clean room quickly?

1. Hardwall Triage Structures and Ceilings
2. LED Lights
3. Air Handling Unit (AHU), with optional Ductwork and Diffusers
4. Pre-Filters
5. HEPA Filters
6. Exhaust Fans
7. Differential pressure gauges
8. Airlocks: Air Showers (optional)
9. Laminar Flow Hoods (optional)
10. Pass-Through Boxes with UV Germicidal Lamps (optional)
11. Control Panels

Detailed Equipment Description and Layout Instructions:

The following will take the negative pressure clean room of ISO8 standard of 5x5m as an example to create.

Hardwall Triage Structures and Ceilings

Description: The containment structure will be modular and includes integrated hardware for a T-grid ceiling system. The T-grid ceiling system is capable of self-supporting the ceiling mount fan filter units or laminar flow ceiling.

• Frame Material can be 304 Stainless Steel, Powder-Coated Steel or aluminum<
• The standard construction cleanroom wall is often epoxy-painted gypsum board on steel studs, and melamine or vinyl on honeycomb core better, also has an additional clear acrylic window or with full clear acrylic wall panel

LED Lights

Description: YANING can provide LED flat panel troffer lights that includes dimmable brightness and 5 selectable color temperatures to achieve the perfect balance of light including 3000K / 3500K / 4000K / 5000K / 6500K

Air Handling Unit (AHU)

Description: The AHU conditions and circulates air through the clean room. It includes heating, cooling, humidification, dehumidification, and filtration components.

• use Yaning standard FFU 575×1175×230mm, Airflow Volume: 1000 m³/h, to meet ISO8, Class 100,000 in Federal Standard 209E, it will need 6 units total. These FFUs will be equipped with HEPA filters and pre-filters.
• Can be used Laminar flow ceiling connected to HVAC system if HVAC (Heating, Ventilation, and Air Conditioning) system supported. The Laminar flow ceiling will equipped with Ductwork, Diffusers, pre-filters and HEPA filters.

Assembly:The FFUs or Laminar flow ceiling will be mounted in the ceiling grid of the cleanroom framework.

Exhaust Fans with HEPA Filters

• Description: The exhaust fans remove air from the clean room, creating negative pressure. HEPA filters ensure the exhaust air is clean.
• Assembly: Connect exhaust fans to the negative pressure plenum. Ensure proper sealing to maintain negative pressure. The exhaust fans are generally near the floor or low on the walls to effectively remove air and contaminants.
• Usage: It needs 4 exhaust fan units with HEPA filters

Differential pressure gauges

• Description: Differential pressure gauges will be Installed at critical points such as entry/exit points and within the cleanroom.
• Assembly: Connect sensors to a central monitoring system with alarms to alert operators if pressure differentials fall outside the desired range.

Cleanroom Airlocks

Description: At the main entry point personnel to Install an air shower or airtight door or Swing doors. Air shower is a cheaper option to ensure proper sealing and functionality of air jets. Air shower can Remove particulate contamination from personnel before they enter the clean room and has proper sealing and interlocking mechanisms.

Laminar Flow Hoods

Description: Set a laminar flow hood as the workstation inside of the modular cleanroom as needed, the laminar flow hood will be equipped with UV germicidal lamps. This is optional, but very effective and safe for work in the negative-pressure cleanroom.

Pass-Through Boxes

Description: Allow materials to be transferred into and out of the clean room without disrupting the air pressure.
It has interlocking mechanisms and can ensure the doors on each side of the pass-through box are not opened simultaneously. Equip UV germicidal lamps inside the pass-through boxes for additional sterilization.

Control Panels

Description: Cleanroom Control Panels centralize control of cleanroom lighting, power, FFU speed, and assignable groups such as laminar flow hood.

Yaning Control Panels provide central control and connection of lights, filters, and the values of Differential pressure gauges. A HEPA Filter Replacement Alarm provides a reliable, quantitative method for determining when a HEPA filter requires replacement. An optional Night Service Switch drops all Fan/Filter Units (FFUs) into a low-energy mode for nights and weekends. Connect sensors of Differential pressure gauges to the Control Panel with alarms to alert operators if pressure differentials fall outside the desired range.

Test and Validate

After the modular clean room is built, the negative pressure test is a key part. Perform pressure differential tests to ensure the clean room maintains negative pressure. Verify the effectiveness of the HEPA filters and other purification equipment. Conduct particle count tests to ensure the clean room meets cleanliness standards.