Designing/Building/Constructing Your Cleanroom
How do you know when you need a cleanroom and what should you know before building or upgrading? Cleanroom design expert, Don Zytka, says “start with the basics” and make sure your company is involved from start to finish.
Editor`s Note: This is the first in a new series of columns that address questions our readers often ask us.
Q:My company is thinking about a cleanroom for its manufacturing process. How do we know if we really need a cleanroom? What`s involved?
J. Kimball, Austin, TX
A: If your customers have not already specified that they want their product processed in a cleanroom, ask yourself if the product or process will fail if it is not processed in a cleanroom environment. Does my competition use cleanrooms? What yield improvements do I expect to see? A cleanroom is designed to deliver filtered air at a specified velocity in a specified direction and at a specified filter level. High efficiency air filters (HEPA) will filter particulates from 0.5 µm and greater; higher efficiency filters (ULPA) will filter particulates from 0.12 µm in size and greater at efficiencies from 99.975 percent to 99.99975 percent and higher. The decision to incorporate clean manufacturing into your manufacturing process or upgrade or expand an existing clean environment is a major investment in terms of development and implementation time and in company dollars. Construction costs can run from hundreds to thousands of dollars per square foot, so it`s highly important to have buy-in from your executive staff. Expect utility costs to increase. Special furniture, tooling and fixtures and gowning will be required, and protocol will have to be enforced. In many cases, cash incentives are offered to personnel who must work in the cleanroom. A great deal of thought must go into the development of a cleanroom to assure the completed cleanroom will pass the form, fit and function test.
Paramount in the development of any clean environment is to have a total understanding of the requirements for the space. Start with the basics. Do you have room for a cleanroom–can existing space be upgraded or expanded or will you have to build from scratch? It is important to understand the cleanliness requirements of your product or process. What size and type of contaminants will affect it? Someone within your company should be designated who understands clean technology and the operating requirements of a clean environment. A cleanroom is not a cleaning machine. To maintain cleanliness levels:
Anything entering the cleanroom environment must itself be pre-cleaned.
Workers must be specially trained to work in a cleanroom.
Special garments are required, which are approved to ensure they will have no negative effect on the process or product. These range from smocks to full body coverage.
Operating and maintenance procedures must be generated and strictly followed.
A cleaning procedure must be established. Ideally, a daily, weekly, monthly and quarterly cleaning schedule should be followed. Cleaning materials must also be approved as having no negative effect on the process or product.
A continual maintenance program must be established to maintain equipment, change pre-filters, etc.
Equipment operating in the cleanroom environment must be specified for the proper cleanliness levels.
Q: What are my options for designing and building a cleanroom environment?
S. Montagameri, Chicago, IL
A: A design/build firm will generate the design, select the equipment and generally use their construction teams to build the cleanroom. An architectural engineering firm will design the environment and work with the construction firm and equipment suppliers. The equipment manufacturer will use their materials and equipment and work with other suppliers and contractors in building the clean environment itself. You may opt to hire a consulting firm to coordinate all aspects of the complete process, including determining your needs to selecting the type of organization to design and build, and final acceptance of the completed cleanroom.
Q: What kind of questions should I be asking during the design phase?
S. Montagameri,Chicago, IL
A:First of all, ask yourself how much cleanroom you really need–what level of cleanliness is really needed for your product or process–then balance this with the size of the budget you have to work with. Will the cleanroom be process specific or should it be flexible to accommodate changing needs? Specific process requirements, such as temperature and humidity, the chemistry to be used in the process, type of process utilities required, type and size of process equipment are questions to be considered. How many employees will be working in the cleanroom environment? Will a continuous monitoring system be required? What about a backup power system? Special requirements are also important: Is the process vibration sensitive? Will there be any special grounding, ESD requirements? And last, but not least–what is the completion schedule? Generally, materials outgas. Will materials inside your cleanroom, below the filters, leave damaging deposits on your process or product?
During the design phase, cleanroom environment acceptance criteria should be established. This criteria should be part of the construction bid package: cleanliness level; contamination recovery rate; air changes; laminarity; noise level; lighting level; and vibration.
Q:What about the construction phase?
S. Montagameri,Chicago, IL
A:Selection and management of the construction team is an important factor in the overall success of any cleanroom project. Make sure the construction firm has built cleanrooms to your required level of cleanliness. Will they assign qualified cleanroom management teams to your project? Will this team be dedicated to your project until its completion? Do they understand your acceptance criteria? Do they understand clean construction techniques? Can they conduct clean construction technique training to all trades?
Remember, you have to have input into the development of your cleanroom, because after the designers and contractors leave, the cleanroom is your responsibility. If it doesn`t meet the needs of your process, you and your company will have lost a great deal of time and money.
During the construction phase, delegate a company representative to work directly with the project superintendent, thus establishing a partnership with the construction team. Your company representative should:
Review and understand all construction documents.
Call a daily meeting with the project superintendent.
Attend all contractor meetings.
Review and process all change orders.
Work with the company finance director on the project status.
Issue weekly status reports.
Inspect the job site on a daily basis.
Communicate to the project superintendent any inconsistencies.
Q: Who certifies my cleanroom?
M. Peterson, Palo Alto, CA
A: Any cleanroom environment should be certified by a qualified certification team before final acceptance.
The certification firm should be hired by the owner, since their acceptance certifies the design as acceptable and that construction was successful. The certification team should have the proper equipment to certify the cleanroom environment to the designed level, as well as qualified technicians to conduct the tests. A formal report should be issued to you, the owner.n
If you have a question you`d like an expert opinion on, send it to:
Susan English, Associate Editor, CleanRooms,
10 Tara Blvd., 5th Floor, Nashua, NH 03062;
or e-mail: [email protected].