How do modular cleanrooms work?

How do modular cleanrooms work?

Modular panels create the enclosure, while engineered filtration, airflow/HVAC, pressure balance, utilities, monitoring, operating practices and installed-system testing create the controlled environment. Panels or HEPA filters alone do not establish ISO class or compliance. Performance depends on the integrated system and verification after installation.

What Makes a Modular Cleanroom a Controlled Environment?

Modularity is a construction method, not a cleanliness performance rating.

The enclosure creates the controlled boundary

Walls, ceiling, doors, glazing, joints, seals and penetrations limit uncontrolled air exchange.

Air treatment controls airborne particles

Filtered supply air circulates and returns or exhausts, diluting or removing particles generated by people, equipment or processes.

Pressure controls the direction of air movement

Pressure results from supply, return and exhaust balance plus leakage, doors, openings and adjacent spaces; positive or negative pressure is risk-based.

Controls and operating practices keep the system stable

Controls may use varied strategies, while sensors, alarms, cleaning, maintenance and personnel discipline affect ongoing performance.

Installed performance must be verified

Testing verifies defined attributes; ISO classification is measured airborne particle concentration under specified conditions [1].

How the Modular Enclosure and Panels Work

Panels create maintainable boundaries, and materials or joints do not assign ISO class.

Wall and ceiling panels

Wall and ceiling panels form the enclosure with cleanable surfaces and structural capacity for specified ceiling equipment.

Panel core versus exposed surface

The core affects structure, thermal and fire behavior, while the facing affects cleanability and chemical resistance.

Doors, windows and room openings

Doors and glazing provide access and visibility, while pass-throughs and equipment openings require pressure and cleanliness coordination.

Joints, seals and corners

Joints, seals and corners control leakage and cleanability, so they require inspection and maintenance.

Utility and duct penetrations

Electrical, gas, water, drain and duct penetrations must be coordinated before fabrication to preserve sealing.

Modular does not automatically mean portable

Relocatability depends on enclosure, HVAC and utilities, and classification is not preserved automatically after relocation.

How Airflow and HEPA Filtration Work

Airflow follows supply, distribution, dilution or removal, then return or exhaust; no universal ACH or FFU rule applies.

Supply air and recirculation

Supply quantity follows heat load, particle generation, recovery needs and occupancy, while recirculation effects are design-specific.

HEPA and ULPA filtration

HEPA and ULPA filters are specified by class, efficiency and test basis, with airflow and pressure drop from product data.

A filter rating does not prove room classification

Filter efficiency describes the filter, not the room; ISO classification is measured airborne particles under specified conditions [1].

Unidirectional and non-unidirectional airflow

Unidirectional or non-unidirectional airflow is selected by process and contamination need, with iso 14644-3 supporting applicable tests [3].

Return-air paths and contamination removal

Return paths must coordinate with supply, equipment layout and occupants to avoid stagnant zones or disrupted patterns.

Localized clean zones

Localized clean zones may provide higher control where the process requires it, but no generic rule applies.

How Pressure and Air Balance Work

Pressure difference is an airflow-balance result involving supply, return, exhaust, leakage, doors, openings and adjacent spaces.

Positive-pressure applications

Positive pressure may protect a cleaner space, but the choice is risk-based and follows the contamination-control strategy.

Negative-pressure or containment applications

Negative pressure may support containment, but negative pressure alone is not containment and other controls may be required.

Pressure cascades between rooms

Pressure cascades and airlocks may be justified where adjacent spaces or transitions require defined relationships.

Doors, leakage and transient conditions

Door openings, penetrations and leakage affect pressure stability, so design and procedures must account for these events.

Monitoring pressure relationships

Pressure sensors and alarms may be required where critical, following application and risk assessment rather than a universal value.

How HVAC and Utilities Support the Cleanroom

HVAC and enclosure are separate but interdependent scopes whose interfaces must be clarified early.

Heating and cooling

HVAC capacity must address heat loads from people, process equipment and external conditions to maintain specified conditions.

Humidity control

Humidity control may be required for process, ESD, condensation or comfort reasons and is not ISO-driven.

Make-up air, exhaust and recirculation

Make-up air replaces exhaust and exfiltration, exhaust removes contaminants or heat, and recirculation effects are design-specific and balanced with exhaust and process needs.

Process exhaust

Process exhaust follows hazard assessment and applicable safety requirements and applies only where the process generates relevant contaminants.

Electrical and process utilities

Power, data, gases, water and drainage must be coordinated with the enclosure, since utility locations affect panel design and access.

Host-building interfaces

Structural capacity, HVAC capacity, fire and building constraints and maintenance access affect modular installation.

How Controls and Monitoring Work

Controls operate systems and monitoring provides evidence, but continuous particle monitoring is not universal.

HVAC and FFU controls

Controls may use varied strategies for start/stop, fan speed, grouping and setpoints, affecting energy use and stability.

Environmental sensors

Pressure, temperature, relative humidity and process-specific sensors provide data whose usefulness depends on selection and placement.

Particle monitoring

Particle monitoring differs from classification because iso 14644-1 classification verifies a state [1], while iso 14644-2 uses risk-based monitoring [2].

Alarms and data logging

Alarms alert operators to excursions, and data logging supports trend review, with limits and escalation defined in advance.

Monitoring does not ｒｅｐｌａｃｅ testing

Trend monitoring is not formal classification or commissioning and does not establish compliance by itself.

How People and Materials Move Through the Cleanroom

People, material and equipment movement can generate contamination, so layout and procedures affect contamination control.

Personnel entry and gowning

Entry sequence and gowning requirements follow the process and cleanliness sector, supported by training and assessment.

Material transfer

Pass-throughs, airlocks or procedures may be used for material transfer depending on cleanliness strategy and risk.

Equipment movement and maintenance

Equipment openings and service routes affect control, and maintenance may require additional precautions.

Clean-to-controlled progression

Routes follow project contamination-control, zoning and pressure strategy; no universal personnel or material flow direction applies.

Operational discipline

Doors, cleaning, transfer procedures and training affect ongoing performance, so procedures should be clear and followed consistently.

How Modular Cleanroom Installation Works

Installation follows a project-specific sequence, and no universal install or testing sequence or fixed duration applies to all projects.

Pre-installation site review

Site review addresses dimensions, levelness, structure, utilities, access, ceiling height and applicable codes.

Layout and enclosure assembly

Walls, ceiling, doors, glazing, joints and openings are assembled according to design, with inspection supporting quality.

HVAC and filtration installation

FFUs, terminals, ducts, returns and exhaust are installed, and enclosure interfaces must be coordinated.

Utilities and controls integration

Power, sensors, data/BMS and process services are connected, with commissioning following installation.

Sealing and construction cleaning

Sealing and construction cleaning occur before testing, and inspection identifies incomplete sealing or contamination.

Installation sequence dependencies

Panel completion does not mean operational room; HVAC, utilities, controls and testing must be completed, with sequence depending on project conditions.

Process diagram in text: Design freeze → Site prep → Enclosure → HVAC/filters → Utilities/controls → Sealing/cleaning → Balancing → Testing → Handover.

How Commissioning and Testing Confirm Performance

Commissioning, classification and qualification are distinct, and testing shows only defined attributes under defined conditions.

Air balance and pressure verification

Air balance and pressure relationships are verified against project criteria before classification where classification is required.

Filter integrity and airflow tests

Filter integrity and airflow tests use applicable methods such as ISO 14644-3 where specified [3].

Particle classification

Particle classification uses ISO 14644-1 airborne-particle classification [1] and is distinct from commissioning and qualification.

Occupancy state must be specified

Classification may be as-built, at-rest or operational, and not all states are automatically required.

Controls and alarm testing

Sensors, alarms and interlocks are tested where applicable, with records documenting process and results.

Commissioning versus qualification

Commissioning verifies that systems function, while qualification may be required in regulated sectors with additional documentation.

Handover records

Handover records may include drawings, balance and test reports, calibration records, manuals, spares and training materials.

How modular cleanrooms Stay Controlled During Operation

Performance depends on operation, cleaning, maintenance and change control, not design and installation alone.

Cleaning programme

Approved surfaces, agents and methods should be specified, defined and followed.

Filter and HVAC maintenance

Filter and HVAC maintenance follows manufacturer recommendations and system design, with no universal replacement interval.

Sensor calibration and monitoring review

Sensors should be calibrated on a planned schedule, and monitoring data should be reviewed for trends.

Door, seal and enclosure inspection

Doors, seals and enclosure surfaces should be inspected for damage, and penetrations should remain sealed.

Change control

Changes may require engineering review and retesting, with significance assessed through change control.

Operations control programme

iso 14644-5:2025 addresses operations control programme requirements [5], covering policies, procedures, training, entry and exit, cleaning, maintenance and monitoring.

What a Modular Cleanroom Cannot Do by Itself

Correcting common misconceptions helps buyers set realistic expectations.

Panels do not create an ISO class

Panels form the enclosure, while ISO class is measured airborne particles under specified conditions [1].

More FFUs do not automatically mean a cleaner room

FFU quantity is a design choice, and room cleanliness depends on the complete system and contamination sources.

HEPA filtration does not establish sterility

HEPA filtration removes airborne particles but does not sterilize surfaces, and a HEPA rating is not room classification.

Positive pressure is not universally correct

Positive pressure protects some spaces while negative pressure supports containment in others, and negative pressure alone is not containment.

Modular construction does not automatically provide regulatory compliance

Modular construction is a building method, and compliance depends on meeting applicable regulatory requirements where relevant.

Relocatability does not preserve classification

Classification after relocation requires re-verification and does not transfer automatically.

Standards and Regulatory Boundaries

ISO standards provide classification, design, testing and operations frameworks, while sector regulations apply only where relevant.

iso 14644-1:2015

ISO 14644-1:2015 addresses particle classification by airborne particle concentration under specified conditions [1].

ISO 14644-2:2015

ISO 14644-2:2015 addresses monitoring using a risk-based approach to provide evidence of continued performance [2].

iso 14644-3:2019

ISO 14644-3:2019 provides supporting test methods used to verify defined performance attributes [3].

iso 14644-4:2022

ISO 14644-4:2022 covers design, construction and start-up from requirements through commissioning and handover [4].

iso 14644-5:2025

ISO 14644-5:2025 addresses operations and specifies requirements for an operations control programme [5].

United States — sterile drug/biological aseptic processing only

FDA 2004 guidance is nonbinding and applies only within the applicable CGMP aseptic-processing scope for sterile drug and biological products [6].

EU / EEA — sterile medicinal-product manufacturing only

EU GMP Annex 1 applies only within the applicable sterile GMP scope for sterile medicinal products [7].

Other sectors and regions

Other sectors and regions may have different requirements, so the actual regulation, customer requirements and authority having jurisdiction should be identified.

Deiiang Company-Published Product Information and Evidence Boundary

Company pages can support Deiiang product-option statements only, not independent performance proof.

Publicly described modular system

Deiiang’s modular clean room page describes modular cleanrooms and states that the structure supports disassembly, reassembly and relocation, per company-published information [8].

Public filtration and control options

Deiiang’s Clean Booth page lists HEPA and ULPA filter options and a group control system for FFUs, per company-published information [9].

Claims not to import

Generic ACH, pressure, compliance, energy, price, speed or performance claims should not be treated as neutral facts.

Project evidence boundary

Project cases, test data, photos, schedules, prices or measured outcomes should not be invented.

What Buyers Should Specify Before Requesting a Quote

Dimensions and ISO class alone are insufficient, so additional requirements must be defined for meaningful comparison.

Process and contamination-control basis

Define contamination sources and control needs, since the basis drives system design.

Cleanliness and test basis

Specify cleanliness level, test basis, occupancy state, test methods and acceptance criteria.

HVAC and pressure requirements

Specify HVAC capacity, temperature, humidity and pressure relationships between spaces.

Enclosure and access

Define enclosure specifications, access requirements, openings, doors, pass-throughs and maintenance access.

Utilities and controls

Specify utility requirements, control and monitoring needs, integration requirements, and sensor and alarm requirements.

Installation and site information

Document site conditions, access and constraints, and clarify installation responsibilities.

Testing and documentation

Specify testing scope, acceptance criteria, documentation and handover records.

Commercial scope

Define scope boundaries, exclusions and responsibilities to support fair comparison.

Modular Cleanroom Procurement Comparison Table

Normalize scope and responsibility rather than headline price.

Desktop comparison table

Mobile card alternative

No calculator recommendation

No generic ACH, FFU or pressure calculator is recommended because design depends on the specific process, layout and requirements.

Final Buyer Checklist

A compact checklist for RFQ and pre-order verification.

Performance

Define cleanliness level, test basis, acceptance criteria, temperature, humidity, pressure and occupancy state.

System interfaces

Identify HVAC, utility and control interfaces, clarify scope boundaries and document site conditions.

Operation

Define cleaning, maintenance and monitoring requirements, specify training and documentation needs, and address change control.

Handover

Define handover documentation, test reports, drawings, manuals, calibration records, warranty and support terms.

FAQs

Answers remain project-specific; verify requirements for the actual application.

How does a modular cleanroom work?

Modular panels create the enclosure, while filtration, airflow, pressure control, utilities, monitoring and operating practices maintain controlled conditions verified by testing.

What controls the cleanliness level inside a modular cleanroom?

Filtration, airflow, enclosure integrity, contamination sources and operating practices all affect cleanliness, and ISO class is measured particles under specified conditions [1].

Do modular cleanrooms always use HEPA filters?

HEPA filtration is common where particle control is required, but configuration depends on the application and a HEPA rating is not room classification.

How is pressure controlled in a modular cleanroom?

Pressure results from supply, return and exhaust balance, leakage, doors, openings and adjacent spaces, with sensors and controls maintaining setpoints.

What should buyers verify before purchasing a modular cleanroom?

Verify scope, performance requirements, test basis, documentation, responsibilities and exclusions, and define acceptance criteria before purchase.

Conclusion — The Whole System Creates the Controlled Environment

A modular cleanroom works as an integrated system: the enclosure contains the volume, filtration and airflow remove particles, pressure guides air movement, and controls and procedures maintain stability. Installed-system testing verifies performance. Panels or filters alone do not establish ISO class or compliance, so buyers should define process requirements and acceptance criteria before specifying a system.

References

1. ISO 14644-1:2015, Cleanrooms and associated controlled environments — Part 1: Classification of air cleanliness by particle concentration. https://www.iso.org/standard/53394.html
2. ISO 14644-2:2015, Cleanrooms and associated controlled environments — Part 2: Monitoring to provide evidence of cleanroom performance related to air cleanliness by particle concentration. https://www.iso.org/standard/53393.html
3. ISO 14644-3:2019, Cleanrooms and associated controlled environments — Part 3: Test methods. https://www.iso.org/standard/60598.html
4. iso 14644-4:2022, Cleanrooms and associated controlled environments — Part 4: Design, construction and start-up. https://www.iso.org/standard/72379.html
5. ISO 14644-5:2025, Cleanrooms and associated controlled environments — Part 5: Operations. https://www.iso.org/standard/88599.html
6. U.S. Food and Drug Administration, Sterile Drug Products Produced by Aseptic Processing — Current Good Manufacturing Practice (2004, nonbinding guidance). https://www.fda.gov/regulatory-information/search-fda-guidance-documents/sterile-drug-products-produced-aseptic-processing-current-good-manufacturing-practice
7. European Commission, EU Guidelines for Good Manufacturing Practice, Annex
8. European Commission, EU Guidelines for Good Manufacturing Practice, Annex 1: Manufacture of Sterile Medicinal Products (2022). https://health.ec.europa.eu/document/download/e05af55b-38e9-42bf-8495-194bbf0b9262_en?filename=20220825_gmp-an1_en_0.pdf
9. Deiiang, Modular Clean Room (company-published). https://www.cleanroomequips.com/Modular-Clean-Room/
10. Deiiang, Clean Booth (company-published). https://www.cleanroomequips.com/CleanBooth/