How to Plan a Cleanroom Design & Build Project
01 December 2021

How to Plan a Cleanroom Design & Build Project

We starts with your process requirements and your business objectives. We then design and construct your cleanroom- based on your budget- from that foundation. Our in-house engineering, design, construction management and project management teams enable us to bring constructability and tool requirements into the cleanroom design flow.

  • All elements of the cleanroom project typically developed by project designer
  • Plan should define the design & construction related requirements for products and processes specified by user and facility management
  • Cleanroom project team- establish goals, objectives, needs of the project, project scope, technical performance requirements, outline schedule & budget, identify project responsibility
  • List of staff-building, environmental, safety, code regulations, good manufacturer practice guidelines
  • Consider cost of impact, schedule of design process, milestones
  • Risks need to be identified & mitigations planned

Cleanroom Contamination Control Considerations

  • All equipment & processes used in cleanroom should be in a matrix listing requirement
  • Additional issues that affect the building design and construct ability
  • Hierarchy of cleanliness should be specified & contamination control concept should be developed
  • Contaminant movement & mitigation need to be analyzed

Cleanroom Site Selection & Services Requirement

  • Ground load-bearing capacity
  • Ground water and soil toxicity
  • Ambient air quality & airborne pollutants
  • Availability of utility and services at site versus the required utility and services to determine if additional services or remote connections from adjacent facilities
  • Environmental issues
  • Site ambient vibration & noise levels determination of their acceptability for the process with or without special treatments
  • Ambient electromagnetic fields
  • Local zoning ordinances & regulation

Cleanroom Critical Flow Arrangements

  • Operations, maintenances and quality personnel need to be consulted throughout the design
  • Efficient operation- a systemic design effort to determine functional interdependences adjacencies & efficient flow to minimize the migration of contaminants and to optimize process flow
  • Design of personnel flow in and out of cleanroom
  • Equipment and materials entering cleanroom must be precleaned and moved through either an airlock or a pass through
  • Exposed room surface finish materials must be compatible with the processes in the cleanroom

Cleanroom Facility Design Considerations

  • Standard-ISO 14644-1
  • The class of airborne particle concentration is specified
  • Levels of other cleanliness attributes
  • Facility Planning- externally -> environment & community
  • Climate, geology, topography, building codes, height, color
  • Architectural Planning- internally driven -> engineer requirements, user requirements, quality requirements, corporate standards
  • Predesign & Design Activities
  • Project profile development
  • Expandability
  • Flexibility
  • Adequacy of space
  • Minimization of classified environments
  • Impacts to site/environment/community
  • Cleaning methods & materials
  • Cleanability and accessibility
  • Construction Methods
  • Standard construction
  • Prefabricated construction
  • Cleanroom construction materials
  • More monolithic, nonporous, non-shedding, easily clean
  • Pressurization-door seals->direction of swing
  • Vibration-internal/external
  • Constructability

General Indoor Design Conditions & Considerations

  • Temperature
  • Personnel considerations
  • Process-related conditions
  • Construction materials and temperature specification
  • Monitor and control
  • Humidity
  • Process equipment can add moisture
  • Exhaust
  • Replacement air should be conditioned before entering the cleanroom
  • The greater amount of outdoor air introduced, the higher the cost of conditioning
  • Airborne Molecular Contamination
  • Makeup Air
  • Air handling units (AHU) requires series of filters to remove particles from ambient air
  • Filters protect the coils & extend life of HEPA/ULPA filters
  • Process Exhaust
  • Filtration System-HEPA/ULPA filters typically mounted to ceiling

Indoor Environmental Quality

  • Air temperatures, humidity, supply air distribution speed

Outdoor Emission Control & Outdoor Air Intake

  • Release of particles, chemical fumes, or microbes

Design for Safety Concerns

  • Physical barriers & zone separation to reduce the impact of sudden dispersion
  • Zone-or room-based air purge system
  • Storage of toxic/flammable material
  • Proper egress path design to reduce the exit distance
  • Isolation of hazardous materials
  • Code requirements
  • Security & Access Control- Protect against unauthorized personnel
  • Building Codes & Standards- Authority having jurisdiction, international codes, national local codes/standards, OSHA, ADA, EPA, NEC

Cleanroom Testing Terminology

  • Airborne Molecular Contamination-AMC
  • Coincidence-presence of 2 or more particles
  • Colony-forming unit (CFU)
  • Condensation nucleus Counter (CNC)
  • Diluter
  • Functional requirement specification (FRS)
  • Macroparticle
  • Master plan
  • National Metrology Institute (NMI)
  • Particle Size Cutoff Device
  • Polydisperse Aerosol
  • Ultrafire Particle
  • Viable Particle

Cleanrooms in Semiconductor & Electronic Facilities

  • Facilities need to be flexible, environmentally benign, extendable, reliable and cost-effective
  • Wafer & chip are terms used to describe the base manufacturing units
  • Wafer-refers to mono-crystalline silicone dishes used to produce integrated circuit devices
  • Wafers & chips are produced in a fabrication facility or “wafer fab” or “fab”

HVAC Configuration Cleanroom

  • Meet heating & cooling needs- satisfies space air cleanliness requirements with that same system
  • Traditionally accomplished air cleanliness- by using high airflow rates
  • Challenge is to configure system when airflow rate required by dilution is higher than required heating & cooling load
  • A cleaner class cleanroom requires higher airflow rate
  • ACH= air changes per hour
  • Engineers first calculate airflow rate required to meet heating/cooling load
  • Then calculate airflow rate to achieve air cleanliness
  • Then use flow ratio to determine best practices
  • Airflow streams can either be mixed, diverted or both

HVAC Design for Various types of Pharma Facilities

  • Primary means of protection from cross-contamination
  • Pharma products in two categories:
  • Nonsterile Products-tablets, capsules, liquids, creams & ointments & medical devices noninvasive
  • Sterile Products-injected into blood stream by syringe or intravenous catheter, medical devices that are inserted into body
  • Two Basic Ingredients:
  • Inactive ingredients
  • Active ingredients

Clean Design

  • Interior surfaces & fitted air delivery systems have some impact on air cleanliness
  • For better HVAC
  • Corrosion-resistant interior surfaces
  • Direct-drive instead of belt-driven fan motors
  • Sealed bearings for motors
  • Ultraviolet (UV) lights for cooling coils
  • Antimicrobial coating on cooling coil drain pans

Design for Redundancy & Reliability

  • Redundancy should be provided at level matches process requirements
  • Addressed at a component level, multiple fans operating in tandem (fan wall), or at system level with multiple air handlers in parallel operation

Cleanroom Airflow Rate

  • Cleanroom height can impact air change rate and air velocity

Cost-Effective Options for Lowering Cleanroom Air Change Rates

  • More options are available than using a high air change rate
  • Some measures can be used to lower the air change rate requirement
  • Selecting equipment, machinery, furniture, and room construction materials with lower particle generation levels
  • Pick lowest particle generation as possible
  • Isolate and remove High-Concentration Particles generated in the cleanroom
  • Enhance surface cleaning protocols to prevent surface particles from turning into airborne particles
  • Control particle entry through supply air
  • Design return and exhaust air systems effectively for particle exit
  • Maintain proper pressurization/no depressurization