Does construction method matter?

As with most things, when building a cleanroom facility, there are options and choices to be made. Most would agree that a new cleanroom project should be cost-effective, designed to suit needs, and meet requirements for testing and certification.

Controlled Environments asked Wayne McGee, President of PortaFab (Chesterfield, MO; www.portafab.com) for his views on some current issues in cleanroom construction.

What are the different methods used to construct cleanrooms?
WM: In a broad sense, facility managers are usually faced with choosing between two primary construction options: standard or modular. Standard construction uses common building materials like blocks or drywall to create walls and ceilings that are covered with epoxy, PVC, or fiberglass.

As the name implies, modular construction uses modular components that can be configured in many different ways and assembled quickly and easily. There are a few varieties; softwall cleanrooms feature plastic sheet wall panels while hardwall styles typically utilize either a panel and post design or monolithic walls that have smooth, easy to clean finishes with minimal ledges and joints.

One other type of construction method is prefabricated. This method has the room created in sections offsite and then delivered to the final facility for quicker installation. It is less disruptive to the operation, but otherwise is very similar to standard construction.

Can you compare standard versus modular construction?
WM: There are many advantages to using modular construction. One of the most important is that you know what you are going to get because the product is extremely consistent from one facility to the next. Modular systems are manufactured in controlled manufacturing environments and have already been validated through extensive real-world use. Next, using modular components significantly reduces design, architecture, and engineering time and associated costs. Once designed, modular cleanrooms can typically be constructed 20-40% faster than cleanrooms built using traditional methods and offer much more flexibility if the cleanroom needs to be moved or re-configured. This last point is incredibly important as facility managers are faced with shorter and shorter timeframes for production start-up.

The biggest disadvantage for modular cleanrooms is that many engineers perceive the costs to be higher because the actual building components often cost more.

Is the up-front cost difference that keeps more facilities from utilizing modular construction?
WM: That’s an interesting point. If you really evaluate total costs, the difference is nominal and modular is often less expensive. Many U.S. companies, however, are just more comfortable with standard construction, so they don’t consider modular as an alternative. In the European market, the use of modular construction is far greater. In fact, we figure it’s about 70% compared to maybe 15% in the U.S. market. That being said, there is a growing trend toward modular construction in the U.S. especially with larger companies that utilize more sophisticated cost analysis in their construction evaluation.

Has the push towards green construction had any effect on the construction method chosen?
WM: We have not seen much demand for “green building” in the cleanroom market, but using modular components has inherent environmental advantages over traditional construction since components can be moved, re-configured, and re-used.