Cleanrooms used for pharmaceutical production, electronics, laboratories, medical devices and other controlled processes require more than ordinary comfort air-conditioning.
A cleanroom HVAC system must support the environmental conditions defined by the process and facility owner. These may include airborne particle concentration, airflow direction, pressure relationships, temperature, humidity and recovery after a disturbance.
The appropriate solution cannot be selected from an ISO class alone. Two facilities with the same airborne-particle classification may require different air-change rates, filter arrangements, temperature limits, humidity controls and monitoring plans.
Successful cleanroom delivery therefore begins with a documented User Requirements Specification, process-risk assessment and contamination-control strategy—not a generic equipment schedule.
What Makes Cleanroom HVAC Different?
Ordinary commercial HVAC primarily provides acceptable temperature, humidity and ventilation for occupants.
Cleanroom HVAC may also need to control:
- Airborne particles
- Airflow direction
- Room-to-room pressure
- Temperature
- Relative humidity
- Outdoor-air load
- Process exhaust
- Contaminant migration
- Recovery time
- Filter condition
- Alarm limits
- Environmental records
The system may require:
- Dedicated air-handling equipment
- Recirculating air systems
- Terminal HEPA filters
- Fan-filter units
- Low-leakage ductwork
- Pressure-independent airflow control
- Room pressure monitoring
- Redundant equipment
- Building-management integration
- Qualification and periodic testing
A cleanroom is not qualified simply because HEPA filters are installed.
Cleanroom Classification Under ISO 14644
ISO 14644-1 classifies air cleanliness by the concentration of airborne particles at defined particle sizes and sampling locations.
The classification does not, by itself, prescribe:
- A universal air-change rate
- A particular HEPA filter grade
- A fixed room-pressure differential
- A standard temperature
- A standard humidity level
- A specific air-handling arrangement
- Microbiological limits
- Product-specific GMP requirements
Those conditions must be established according to the process, risk, applicable regulations and owner requirements.
ISO 14644-2 addresses monitoring intended to provide evidence of cleanroom performance related to airborne-particle cleanliness. ISO 14644-3 covers cleanroom test methods, while ISO 14644-4 addresses design, construction and start-up.
The project team should confirm the current applicable standards and regulatory requirements before design.
ISO Classes and Pharmaceutical Grades Are Not Identical
ISO airborne-particle classes should not be treated as interchangeable with pharmaceutical clean-area grades.
Pharmaceutical facilities may have additional requirements concerning:
- At-rest and in-operation conditions
- Viable contamination
- Personnel practices
- Gowning
- Cleaning and disinfection
- Environmental monitoring
- Product exposure
- Aseptic processing
- Material movement
- Qualification
- Documentation
- Data integrity
The room classification and HVAC design should therefore be based on the actual manufacturing activity.
A pharmaceutical packaging room, non-sterile production room and aseptic processing area may have very different requirements even if they are all informally described as cleanrooms.
Start with a User Requirements Specification
The User Requirements Specification, or URS, defines what the cleanroom must achieve.
A suitable URS may identify:
- Intended process
- Product or material
- Required classification
- At-rest and in-operation states
- Occupancy
- Process-equipment heat load
- Particle-generation sources
- Temperature range
- Humidity range
- Pressure relationships
- Outdoor-air requirement
- Exhaust requirement
- Hazardous materials
- Recovery expectation
- Redundancy
- Monitoring points
- Alarm limits
- Qualification tests
- Documentation
- Maintenance access
- Future expansion
Equipment should not be selected before the process requirements are understood.
A conservative design is not necessarily one that uses the highest filtration grade or greatest airflow. Excessive airflow may increase energy use, noise, equipment size and maintenance without improving the process outcome.
Contamination-Control Strategy
The contamination-control strategy should consider how contaminants are generated, transported and removed.
Potential sources include:
- Personnel
- Gowning
- Materials
- Process equipment
- Product handling
- Doors
- Leaks
- Maintenance activity
- Cleaning
- Outdoor air
- Supply ductwork
- Damaged filters
- Adjacent rooms
Control measures may include:
- Air filtration
- Airflow direction
- Pressure cascade
- Airlocks
- Gowning procedures
- Material transfer
- Cleaning
- Restricted access
- Process containment
- Environmental monitoring
- Preventive maintenance
- Qualification and requalification
HVAC is only one part of contamination control.
Cleanroom Air-Handling Architectures
Cleanrooms can use different air-handling arrangements.
Central Air-Handling Unit
A central air-handling unit may supply conditioned and filtered air to one or more clean spaces.
The unit may include:
- Outdoor-air intake
- Prefilters
- Intermediate filters
- Cooling coil
- Heating or reheat
- Dehumidification
- Humidification where required
- Supply fan
- Final filters
- Controls
- Monitoring instruments
Recirculating Air-Handling Unit
A recirculation unit moves cleanroom return air through conditioning and filtration equipment before returning it to the space.
Recirculation can support high airflow without conditioning the same quantity of outdoor air.
Fan-Filter Units
Fan-filter units combine a fan and high-efficiency filter in a ceiling or process-level module.
They may be used in:
- Modular cleanrooms
- Unidirectional airflow zones
- Mini-environments
- Retrofitted facilities
- Areas requiring distributed airflow control
Dedicated Outdoor-Air System
A dedicated outdoor-air system, or DOAS, may be used to condition required outside air and manage part of the latent load separately from recirculated cleanroom air.
However, cleanrooms do not universally require a DOAS. The final architecture depends on:
- Outdoor-air requirement
- Exhaust volume
- Pressurization
- Humidity load
- Process load
- Existing utilities
- Redundancy
- Energy strategy
- Available space
The system should be selected by calculation and risk assessment rather than assumed from one standard cleanroom diagram.
Outdoor Air and Makeup Air
Outdoor air may be required for:
- Occupant ventilation
- Replacement of exhaust air
- Maintaining pressure relationships
- Diluting selected contaminants
- Supporting the approved process
In Clark and Central Luzon, outdoor air can carry significant moisture during humid periods.
Introducing more outdoor air than required can increase:
- Cooling load
- Dehumidification load
- Reheat demand
- Coil size
- Energy consumption
- Condensation risk
Outdoor-air quantity should be coordinated with process exhaust, room leakage and required pressurization.
HEPA Filtration
HEPA filters are widely used in cleanroom applications because they remove a high percentage of particles within their tested performance range.
Filter specifications should identify:
- Applicable test standard
- Filter classification
- Rated airflow
- Initial pressure drop
- Final recommended pressure drop
- Frame material
- Seal type
- Gasket or gel-seal arrangement
- Installation housing
- Scan-test requirements
- Face velocity
- Operating temperature and humidity
- Chemical compatibility
- Required documentation
“99.97% at 0.3 micron” is a commonly used description, but it should not replace the actual manufacturer test standard and filter classification.
Filter performance should be evaluated according to the applicable test method, including the filter’s most penetrating particle size where relevant.
ULPA Filtration
ULPA filters provide higher filtration performance under their applicable test classification.
They may be appropriate for selected semiconductor, electronics or critical-process applications.
However:
- ISO Class 5 does not automatically require ULPA filters.
- ULPA filters are not automatically better for every cleanroom.
- Higher-efficiency filters may produce greater pressure drop.
- The system fan and housing must support the selected filter.
- Installation leakage can undermine filter performance.
- The process requirement should justify the selection.
HEPA versus ULPA should be determined from the contamination-risk assessment and required performance—not marketing language.
Filtration Stages
A cleanroom air-handling system may use several filtration stages.
A possible arrangement includes:
- Coarse prefilter
- Intermediate or fine filter
- Terminal HEPA or ULPA filter
The exact grades and locations depend on the system design.
Prefilters help protect coils, fans and final filters from excessive loading. They do not replace terminal high-efficiency filtration where terminal filtration is required.
The project should confirm:
- Filter availability
- Replacement access
- Differential-pressure monitoring
- Safe handling
- Disposal procedure
- Stock of replacement filters
- Filter-change method
- Protection from installation damage
Terminal HEPA Filters
Terminal filters are installed near the point where supply air enters the cleanroom.
Potential advantages include:
- Reduced risk of downstream duct contamination
- Local filter integrity testing
- Defined clean-air delivery
- Support for room-level qualification
The ceiling grid, housings and seals must be installed carefully.
A high-quality HEPA filter cannot compensate for:
- A leaking housing
- A damaged gasket
- A poorly fitted ceiling
- Unsealed service penetrations
- Contaminated ductwork
- Incorrect airflow balance
Air Change Rates
Air changes per hour, or ACH, describe the theoretical number of room air volumes supplied within an hour.
There is no universal ACH value for each ISO class.
The required airflow depends on:
- Particle-generation rate
- Process
- Occupancy
- Room geometry
- Air-distribution pattern
- Recovery requirement
- Heat load
- Exhaust
- Filtration arrangement
- Ceiling coverage
- Equipment layout
- Cleanliness target
Published rules of thumb may be useful during early planning, but the final airflow should be supported by design calculations, risk assessment, experience and qualification results.
Specifying an unnecessarily high ACH can increase capital and energy costs.
Unidirectional and Non-Unidirectional Airflow
Unidirectional Airflow
Unidirectional airflow supplies air in a generally consistent direction across a critical zone.
It may be used where the process requires sweeping contaminants away from exposed products or sensitive equipment.
Performance depends on:
- Supply coverage
- Air velocity
- Return location
- Equipment obstruction
- Personnel movement
- Process layout
- Filter condition
Non-Unidirectional Airflow
Non-unidirectional airflow uses clean, filtered air to dilute and remove contaminants through a mixed airflow pattern.
It may be suitable for less critical cleanroom applications.
The correct approach depends on the process and contamination-control strategy.
Smoke visualization may be used during qualification or studies to evaluate airflow patterns where required.
Room Pressure Relationships
Pressure differences can help influence airflow between adjacent rooms.
A positive-pressure room tends to direct air outward when an opening or leakage path exists. This may help protect a clean process from a less clean surrounding area.
A negative-pressure room tends to draw air inward. This may be required to contain hazardous, potent, infectious or sensitizing materials.
Cleanrooms should not automatically be designed as positive pressure.
The pressure strategy must consider:
- Product protection
- Personnel protection
- Environmental protection
- Process hazards
- Airlocks
- Exhaust
- Door operation
- Leakage
- Emergency conditions
Pressure Differential Values
There is no single pressure difference suitable for every cleanroom boundary.
The design should consider:
- Door opening force
- Envelope leakage
- Room classification
- Airlock arrangement
- Process containment
- Exhaust variation
- Measurement accuracy
- Alarm deadband
- Pressure recovery
- Building pressure
An excessively high differential may make doors difficult to operate and increase leakage.
The project should specify target values and acceptable operating ranges rather than relying on one generic number.
Airlocks and Gowning Rooms
Airlocks help control movement between spaces with different cleanliness or containment requirements.
Possible types include:
- Personnel airlocks
- Material airlocks
- Gowning rooms
- Pass-through chambers
- De-gowning areas
- Decontamination airlocks
Door interlocks may help prevent both doors from being opened simultaneously under normal conditions.
However, interlocks must be coordinated with:
- Emergency egress
- Fire alarm operation
- Power failure
- Accessibility
- Manual override
- Pressure recovery
- Access control
- Material movement
- Cleaning
- Rescue procedures
An interlock should not trap occupants during an emergency.
Temperature Control
Cleanroom temperature requirements should be established by the process and user needs.
Temperature affects:
- Process stability
- Equipment heat rejection
- Personnel comfort in cleanroom garments
- Relative humidity
- Product properties
- Measurement accuracy
- Static control
- Microbial growth conditions
A narrow tolerance may require:
- Stable chilled-water or refrigerant capacity
- Accurate sensors
- Suitable control valves
- Reheat
- Proper air distribution
- Reduced load variation
- Appropriate controller tuning
The design should distinguish between the desired operating band and the sensor or control-system accuracy.
Relative Humidity and Dew Point
Cleanroom humidity requirements vary by industry and process.
Humidity may affect:
- Electrostatic discharge
- Hygroscopic materials
- Pharmaceutical stability
- Condensation
- Corrosion
- Personnel comfort
- Microbial risk
- Process yield
There is no universal 40–45% RH requirement for all semiconductor or pharmaceutical cleanrooms.
The appropriate range should be supplied by the process owner.
A three-percentage-point excursion should not be claimed to invalidate an entire production lot unless that conclusion follows the facility’s approved process specification and quality investigation.
Dehumidification
In humid climates, cooling coils may need to reduce supply-air dew point sufficiently to manage the moisture load.
The system may also require:
- Reheat
- Desiccant dehumidification
- Dedicated outdoor-air treatment
- Reduced infiltration
- Controlled exhaust makeup
- Vapor control
- Accurate humidity sensors
The appropriate method depends on:
- Outdoor design conditions
- Required room dew point
- Process moisture
- Occupancy
- Exhaust
- Available utilities
- Energy use
- Control tolerance
VRF equipment alone should not automatically be assumed capable of maintaining a demanding cleanroom dew point.
Cooling-Load Calculation
Cleanroom cooling calculations should include:
- Envelope load
- Outdoor-air load
- Process-equipment load
- Lighting
- Personnel
- Fan heat
- Duct heat gain
- Exhaust makeup
- Dehumidification
- Reheat
- Equipment diversity
- Future expansion
High recirculation airflow does not necessarily mean all the air requires full outdoor-air cooling and dehumidification.
The air-handling architecture should distinguish sensible, latent and process loads appropriately.
Cleanroom HVAC for Semiconductor and Electronics Facilities
Electronics and semiconductor processes may require control of:
- Airborne particles
- Temperature
- Humidity
- Static electricity
- Airborne molecular contamination
- Process exhaust
- Equipment heat loads
- Vibration
- Tool-specific environments
An ISO particle class does not address chemical contamination, molecular contamination, electrostatic discharge or vibration automatically.
These requirements should be defined separately.
Photolithography, assembly, testing and support areas may require different environmental conditions.
Cleanroom HVAC for Pharmaceutical Facilities
Pharmaceutical HVAC design depends on:
- Sterile or non-sterile production
- Open or closed process
- Product exposure
- Potency and toxicity
- Cross-contamination risk
- Microbial-control requirements
- Material and personnel flows
- At-rest and in-operation conditions
- Cleaning and disinfection
- Applicable GMP requirements
Pressure direction should consider both product and personnel protection.
A facility handling hazardous or potent compounds may require containment rather than a simple outward positive-pressure cascade.
The owner’s quality and validation teams should participate throughout the project.
Environmental Monitoring
Environmental monitoring may include:
- Non-viable particle counts
- Viable air sampling
- Surface sampling
- Temperature
- Humidity
- Differential pressure
- Airflow
- Equipment alarms
The monitoring plan should define:
- Sampling locations
- Frequency
- Alert limits
- Action limits
- Instrument requirements
- Calibration
- Data review
- Investigation procedures
- Record retention
- Response to excursions
ISO particle classification does not establish microbiological performance.
Pharmaceutical facilities may require separate viable environmental-monitoring programs based on the process and applicable GMP requirements.
BMS and Cleanroom Monitoring
A Building Management System may monitor:
- Room temperature
- Relative humidity
- Differential pressure
- Supply-air temperature
- Fan status
- Filter differential pressure
- Damper position
- Valve position
- Equipment alarms
- Selected energy data
Critical monitoring should address:
- Sensor location
- Sensor accuracy
- Calibration
- Alarm delay
- Alarm deadband
- User permissions
- Audit trails
- Data retention
- Time synchronization
- Backup
- Network failure
- Data review
A BMS display does not prove that the room remains classified. Classification and ongoing evidence require the appropriate testing and monitoring program.
Alarm Management
Cleanroom alarms may include:
- Room pressure outside limits
- Temperature excursion
- Humidity excursion
- AHU failure
- Fan-filter unit failure
- High filter pressure
- Sensor failure
- Door held open
- Communication loss
- Exhaust failure
Alarm settings should distinguish among:
- Warning
- Alert
- Action
- Critical condition
- Maintenance event
The exact terminology and response should follow the facility’s approved procedures.
A brief door opening should not necessarily generate the same response as an extended pressure failure.
Access Control Integration
A cleanroom may use access control to restrict entry to trained and authorized personnel.
Possible functions include:
- Credentialed entry
- Time schedules
- Training-status integration
- Door interlocks
- Visitor restrictions
- Entry-event logs
- Door-held alarms
- Temporary contractor access
Access logs can support investigations and procedural control. They do not independently establish GMP compliance or confirm that a person followed the correct gowning procedure.
Door locks and interlocks must be coordinated with emergency egress and the pressure-control strategy.
Fire and Life-Safety Coordination
Cleanroom partitions, ducts, doors and services must be coordinated with the approved fire- and life-safety design.
Depending on the project, coordination may include:
- Fire-rated penetrations
- Fire or smoke dampers
- Fire alarm devices
- Detection
- Suppression systems
- Emergency power
- Door release
- Smoke control
- Process shutdown
- Exhaust operation
- Emergency ventilation modes
A fire or smoke damper is not automatically required at every cleanroom duct penetration. Requirements depend on the fire-rated construction and approved design.
Dampers can also affect cleanroom pressure and airflow, so their location and emergency sequence must be coordinated.
Clean-Agent Suppression and HVAC
Where a clean-agent fire-suppression system is used, room integrity, ventilation shutdown and damper operation may be part of the approved fire-protection design.
The required sequence depends on:
- Agent
- Room
- Hazard
- Exhaust
- Door leakage
- Dampers
- Pressure relief
- Fire alarm
- Equipment shutdown
- Authority requirements
Do not assume that every cleanroom AHU must shut down in exactly the same way.
The sequence should be prepared and tested with the fire-protection professionals and equipment suppliers.
Ductwork and Leakage Control
Cleanroom ductwork should be designed and installed to support the required pressure and cleanliness performance.
Considerations include:
- Duct leakage class
- Sealants
- Access doors
- Internal cleanliness
- Insulation
- Condensation control
- Fire-rated penetrations
- Flexible connections
- Vibration
- Support
- Cleaning access
- Balancing devices
- Sensor installation
Ducts and air-handling equipment should be protected from contamination during construction.
Dirty ductwork connected to new terminal filters can shorten filter life and complicate commissioning.
Cleanroom Envelope
The room envelope affects HVAC stability.
Important features include:
- Low-leakage wall and ceiling systems
- Sealed penetrations
- Suitable doors
- Flush surfaces
- Cleanable materials
- Controlled ceiling-grid leakage
- Sealed service openings
- Compatible lighting fixtures
- Appropriate flooring and coving
- Maintenance access
A leaking cleanroom envelope may require excessive supply air to maintain pressure.
Pressure problems should not automatically be corrected by increasing fan speed without investigating leakage.
Commissioning and Qualification
Cleanroom commissioning verifies that the installed systems operate according to the approved design.
Qualification may include documented activities such as:
- Design review
- Installation verification
- Operational verification
- Performance verification
- Calibration review
- Documentation review
The owner’s quality system determines the required qualification structure and terminology.
Potential tests include:
- Airflow volume
- Airflow velocity
- Room air balance
- Differential pressure
- HEPA filter integrity
- Airflow visualization
- Particle classification
- Recovery
- Temperature
- Humidity
- Sound and vibration where required
- Alarm operation
- BMS trends
- Door interlocks
- Emergency operation
The testing organization, methods and acceptance criteria should be agreed before construction is completed.
HEPA Filter Integrity Testing
Filter integrity testing evaluates the installed filter and seal arrangement for unacceptable leakage.
It is different from checking only the pressure drop.
A filter may have acceptable resistance while still having:
- Media damage
- Frame leakage
- Seal leakage
- Housing leakage
- Installation defects
Testing should use the applicable method, instruments and acceptance criteria.
Failed filters or seals require investigation, corrective action and documented retesting.
Particle Classification Testing
Classification testing should follow the applicable ISO 14644 requirements.
The test plan should define:
- Room state
- Sampling locations
- Particle sizes
- Sample volume
- Instrument calibration
- Room layout
- Equipment condition
- Occupancy condition
- Acceptance criteria
- Reporting
A single handheld reading does not constitute complete room classification.
Recovery Testing
Recovery testing may be used to assess how quickly a room returns to an acceptable particle condition after a defined disturbance.
The requirement and method depend on:
- Cleanroom class
- Airflow
- Process
- Owner requirements
- Applicable standards
Recovery performance should not be inferred only from air-change rate.
Actual testing may reveal airflow short circuits, poor returns or obstructions.
Testing Under At-Rest and In-Operation Conditions
Cleanroom performance may differ significantly with personnel and equipment present.
At-rest testing generally evaluates the completed installation with equipment in place but without normal operating personnel, according to the defined condition.
In-operation testing evaluates the room during the specified operating state.
The required test states should be defined in the URS and qualification plan.
An acceptable at-rest result does not automatically establish acceptable in-operation performance.
Energy Efficiency
Cleanrooms can consume significant energy because of high airflow, pressure control, dehumidification and continuous operation.
Potential efficiency measures may include:
- Right-sizing airflow
- Efficient fans
- Variable-speed drives
- Appropriate filtration
- Low-pressure-drop components
- Efficient cooling equipment
- Heat recovery where suitable
- Optimized outdoor air
- Validated setback modes
- Good envelope sealing
- Clean filter replacement
- Accurate sensors
- Effective commissioning
Energy-saving changes should not compromise contamination control, pressure, recovery or process requirements.
Setbacks should be supported by risk assessment and requalification where required.
Preventive Maintenance
Cleanroom HVAC maintenance may include:
- Prefilter replacement
- Intermediate-filter replacement
- HEPA pressure monitoring
- HEPA integrity testing
- Fan inspection
- Coil cleaning
- Drain-pan cleaning
- Condensate inspection
- Belt and bearing inspection
- Sensor calibration
- Pressure-monitor testing
- Damper and valve testing
- Airflow verification
- BMS alarm testing
- Door and interlock checks
- Duct inspection
- Envelope inspection
- Documentation updates
Maintenance work itself can introduce contamination. Activities should follow approved procedures for access, cleaning, isolation and restoration.
HEPA Filter Replacement
HEPA filters should not be replaced according to one arbitrary calendar period.
Replacement may be based on:
- Excessive pressure drop
- Integrity-test failure
- Physical damage
- Process contamination
- Facility procedure
- Manufacturer recommendations
- Qualification results
Filter replacement should consider:
- Safe removal
- Bagging
- Hazardous contamination
- Installation direction
- Seal condition
- Housing cleaning
- New filter documentation
- Integrity testing
- Airflow rebalance
- Area cleaning
- Requalification
Hazardous-process filters may require specialized containment and disposal procedures.
Clark and Central Luzon Conditions
Cleanroom HVAC projects in Clark and nearby Central Luzon industrial areas should account for:
- Warm outdoor temperatures
- High seasonal humidity
- Heavy rain
- Outdoor dust
- Power interruptions
- Lightning and surge exposure
- Industrial process loads
- Facility expansion
- Maintenance support
- Replacement-filter availability
Outdoor design conditions and site data should be used for calculations.
A generic Metro Manila weather assumption may not reflect the project’s exact location and operating requirements.
Regulatory and Authority Coordination
Applicable requirements depend on the facility type and process.
Coordination may involve:
- Philippine FDA
- PEZA or the applicable zone authority
- Bureau of Fire Protection
- Local building authorities
- Department of Environment and Natural Resources
- Department of Labor and Employment
- Owner quality and validation teams
- Other industry-specific bodies
Installing HEPA filtration does not automatically produce FDA, GMP, ISO or PEZA compliance.
Compliance depends on the complete facility, process, documentation, qualification and operating system.
Requirements should be confirmed directly with qualified professionals and the relevant authorities.
Procurement Checklist
Before specifying a cleanroom HVAC system, ask:
- What process will take place?
- What airborne-particle classification is required?
- Is the classification required at rest, in operation or both?
- What temperature and humidity ranges are process-driven?
- What pressure relationships are required?
- Is the goal product protection, containment or both?
- What personnel and material flows are planned?
- Which filters and test standards apply?
- Is HEPA or ULPA filtration justified?
- What outdoor air and exhaust are required?
- What process equipment generates heat or contaminants?
- What redundancy is required?
- What environmental monitoring is included?
- What BMS points and alarms are required?
- What qualification tests and acceptance criteria apply?
- Who is responsible for validation?
- What fire and suppression interfaces are required?
- How will maintenance and filter replacement be performed?
- What documents and certifications must be turned over?
- What happens during power, fan or control failure?
- What future expansion is anticipated?
The final design should be based on a coordinated URS, points list, room data sheet, airflow diagram, pressure diagram and qualification plan.
Frequently Asked Questions
What is a cleanroom HVAC system?
It is an HVAC system designed to support specified environmental conditions such as airborne-particle cleanliness, airflow, pressure, temperature and humidity.
Does installing HEPA filters create a cleanroom?
No. Cleanroom performance also depends on airflow, room construction, pressure, operations, cleaning, personnel and qualification.
Does every ISO Class 5 cleanroom require ULPA filters?
No. Filter selection should be based on the contamination risk, design and required performance.
What HEPA efficiency should be specified?
The specification should reference the applicable filter classification and test standard, rated airflow, pressure drop and installed integrity-testing requirements.
How many air changes does a cleanroom need?
There is no universal value based only on ISO class. Airflow depends on the process, particle generation, occupancy, layout, heat load and recovery requirement.
Should every cleanroom be positively pressurized?
No. Positive pressure may protect a process, while negative pressure may be required for hazardous-material containment.
What relative humidity should a cleanroom maintain?
The process owner should define the required range. There is no universal humidity range for all semiconductor or pharmaceutical cleanrooms.
What is the difference between classification and monitoring?
Classification determines whether the cleanroom meets the defined airborne-particle class under specified conditions. Monitoring provides ongoing evidence of selected performance parameters.
How often should HEPA filters be replaced?
Replacement should be based on pressure drop, integrity, condition, process requirements and facility procedures—not one universal schedule.
What is HEPA integrity testing?
It evaluates the installed filter, housing and seal for unacceptable leakage using an applicable test method.
Can a BMS prove that a cleanroom remains classified?
No. The BMS can monitor selected conditions, but classification requires the applicable testing and monitoring program.
Can access control be connected to a cleanroom airlock?
Yes, when the access-control, door-interlock, pressure and emergency-egress functions are properly coordinated.
Does cleanroom HVAC guarantee GMP compliance?
No. GMP compliance depends on the complete facility, process, quality system, documentation, qualification and operations.
Does Infinite Systems serve cleanroom projects in Clark?
Yes. Infinite Systems can assess, design, supply, install, integrate and maintain suitable cleanroom HVAC, ventilation, filtration, controls and monitoring systems for Clark, Pampanga and other Central Luzon locations.
Planning a Cleanroom HVAC Project in Clark?
Infinite Systems can assess your process requirements, room classifications, temperature and humidity limits, pressure relationships, filtration, airflow, exhaust, controls and qualification scope.
We can help develop a coordinated solution covering cleanroom HVAC, HEPA filtration, ventilation, BMS monitoring, access-control interfaces, testing and preventive maintenance.
Request a Cleanroom HVAC Assessment