How to Plan a Cleanroom Design & Build Project

March 17, 2020

Cleanroom Guide & Considerations

Planning a cleanroom can be an overwhelming task! From site selection to calculating airflow changes and MEP requirements to clash coordination and onsite execution, there are no minor details. To hit your key dates for turnover and validation, your team needs to have an organized plan from the beginning. Below you will find helpful considerations, tips, and guides for designing and building your next cleanroom project.

Let’s start with a basic overview.

All the elements of a cleanroom project are typically developed by a team of project designers, engineers, construction managers, project managers, and some sort of management team. This can range from CEOs to directors of engineering or operations to mid-range facility managers. When the thought of building a cleanroom comes to fruition, some questions to prepare for are:

  • What is this cleanroom going to be used for? (Product development, packaging, research & development etc.)
  • What process systems are going into the space?
  • Do you have a rough estimate on dimensions?
  • ISO classification requirements?

Once you finalize your team and have a good grasp conceptually on your cleanroom, the next steps are strategizing the project. You will want to establish:

  • Goals
  • Objectives
  • Project needs
  • Project scope
  • Technical performance requirements
  • Outline schedule & budget
  • Identify project responsibility
  • Risks

Other variables you will need to plan for are safety and code regulations, GMP practice guidelines, cost of impact, procurement, and design milestones.

What are some cleanroom contamination control considerations?

One of the biggest threats to contamination in a cleanroom is airborne molecular contaminants (AMC). These contaminants run a risk to compromising your product, process, and personnel inside the cleanroom. Some other sources of contamination can be from solvent evaporation, plasticizers from off-gassing of polymers, acidic and basic compounds that react to forms of elemental compounds. It is important to create a list of all equipment and processes that are going to be used in the cleanroom. This list will help you narrow down an ISO classification for the space which will influence your design and constructability. Once you identify the ISO classification for your cleanroom, you will want to develop a hierarchy of cleanliness which will help with airflow design and personnel flow.

What you need to think about when selecting a cleanroom project site?

Biotechnology Manufacturing Site

Determining an ISO classification and process requirements are important, but selecting a site location is just as important. Some variables you need to consider are:

  • Ground load-bearing capacity
  • Ground water and soil toxicity
  • Ambient air quality & airborne pollutants(around the site)
  • 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

What are critical flow arrangements in a cleanroom?

Computational Fluid Dynamics model for airflow in a cleanroom

Everything from operations, maintenances, and quality personnel to flow of air in the cleanroom need to be consulted throughout the entire design process. An efficient cleanroom operation is a systemic design effort that determines functional interdependences adjacencies and efficient flow to minimize the migration of contaminants and to optimize process flow. This means design flow arrangements in and out of the cleanroom. If your cleanroom has equipment and materials entering it, these items must be precleaned and moved through either an airlock or a pass through.

What are some a cleanroom design build project?

Understanding environmental factors is an important element when designing and building a cleanroom. Not having proper airflow, temperature control, or understanding the various airborne contaminants can put your product, process, and personnel at risk. Here is a list of considerations:

  • Standard-ISO 14644-1
    - The class of airborne particle concentration is specified
    - Levels of other cleanliness attributes
  • Facility planning- externally driven - 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

Pharmaceutical Manufacturing Cleanroom

What indoor design features do you need to consider for a cleanroom?

  • Temperature
    - Personnel considerations
    - Process-related conditions
    - Construction materials and temperature specifications
    -Monitor and control
  • Humidity
    - Process equipment can add moisture
    - Bacteria growth can flourish
    - Equipment can corrode
    - Static build-up
  • 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
    - Contamination can be from solvent evaporation, plasticizers from off-gassing, and acidic & basic reactions
  • 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
    - Exhaust air should be kept to a minimum, consistent with code, personnel, and process requirements
  • Filtration System
    - HEPA/ULPA filters typically mounted to ceiling

What goes into determining indoor environmental quality of a cleanroom?

  • Air temperatures
  • Humidity
  • Supply air distribution speed

What are the safety concerns for designing a cleanroom?

There are a variety of safety concerns for a cleanroom. Whether you are experimenting with a new treatment, handling a wafer chip, or packaging products, a compromise to your cleanroom can put your personal, your product, and your consumer at risk. When designing for safety you will want to include physical barriers and zone separation to reduce the impact of sudden dispersion. You will want to incorporate a zone-or room-based air purge system as well as an area for storage of toxic/flammable materials and isolation of hazardous materials. Personnel flow is critical so planning a proper egress path to reduce the exit distance is very helpful. As important as having an exit strategy, your cleanroom needs to have some sort of security & access control to protect workers from unauthorized visitors. Here are some building codes to keep in mind:

  • Authority having jurisdiction
  • International codes
  • National local codes/standards

Cleanroom testing terminology you should know!

  • 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
Man walking into a semiconductor cleanroom fab

Cleanrooms in semiconductor & electronic facilities

A semiconductor fab is a manufacturing plant in which raw silicon wafers are turned into integrated circuits. Photolithography is a part of the manufacturing process inside of the cleanroom. This process involves photographing the circuit pattern on a photosensitive substrate and chemically etching away the background. These facilities need to be flexible, environmentally benign, extendable, reliable, and cost-effective. Chip manufacturers face a variety of challenges when designing and operating a semiconductor cleanroom. Extremely detailed processes and controlled environments are essential to produce wafers. When one speck of dust can destroy the functionality of a chip, the only way to avoid contamination is to control the environment. Semiconductor cleanroom environments must be engineered to control static, particulate matter, outgassing, and other sources of contamination and compromising conditions. Environmental control is critical and maintaining the required levels of air purity is a non-negotiable for total performance of the cleanroom. More design considerations here!

Cleanroom facility design for various types of pharmaceutical facilities

Cleanrooms play a vital role for pharmaceutical companies in ensuring that their products are safe to bring to market. Treatments need to be produced, handled, and packaged in a space where cross-contamination is not an issue. Pharmaceutical products are categorized by:

  • 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

You can read more Pharmaceutical design considerations here.

Cleanroom HEPA filters and walkable ceiling lights

HVAC cleanroom design and configuration

The HVAC system can have a significant impact on the product being produced. Whenever the product is exposed to the room environment, the HVAC system becomes the primary means of protection from cross-contamination.  The product can become contaminated when it is exposed to the room environment or when surfaces that encounter it are exposed. Your HVAC design needs to satisfy the space air cleanliness requirements (ISO Classifications). Traditionally, this is accomplished by using high airflow rates to move air through the cleanroom effectively. Note that a cleaner ISO classification requires higher airflow rates, and that the height of the cleanroom can impact air change rates as well as air velocity.  Calculating airflow usually starts with the engineer identifying the heating/cooling load. Then they calculate the airflow rate and determine best practices for these flow rates.

What are some cost-effective options for lowering cleanroom air change rates?

Some options to lower air change rates can come down to selecting equipment, machinery, furniture, and room construction materials with lower particle generation levels. You will want to pick the lowest particle generation as possible to help maintain the level of cleanliness. You can also isolate and remove high-concentration particles generated in the cleanroom as well as enhance cleaning protocols to prevent build up of surface particles becoming airborne particles. Other options are to:

  • Control particle entry through supply air
  • Design return and exhaust air systems effectively for particle exit
  • Maintain proper pressurization/no depressurization

How corporate clean design for your cleanroom

  • 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

These guidelines is only just the beginning to designing and building a cleanroom. Check out our blog for more tips and considerations for cleanrooms across a variety of industries.  

Bryan Phelan
Managing Partner, Director of Customers

As managing partner, Phelan is responsible for ensuring client satisfaction, shaping the company’s strategic direction, and managing all compliance aspects of the organization.

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