With any lab environment, lab designers are concerned about hazards and chemicals, and plan the safest lab they can for the given science conducted. The biggest job is to keep these hazards and chemicals away from the staff, which can be done in multiple ways. One way, and probably the most common, is fume hoods. However, with cleanrooms, lab designers must also maintain cleanliness of the air by recirculation through HEPA filtration and not throw away energy associated with one-pass air normally used in labs.
These two approaches work completely against each other. Thus, lab designers are challenged to find a balance. AECOM achieved just this in their recent work at NASA Langley Research Center. In addition, the facility is designed to be flexible, so it can meet various changing needs over time.
“The idea is really trying to understand exactly what the needs are of the individual users, whether it truly is the cleanliness that’s required and to what degree; Class 100,000, 10,000, 1,000, all the way to Class 100,” says Edward Weaver, VP of AECOM. “We provided NASA Langley with flexible space so they never need to operate past their requirements in the space because, in the end, that will just cost more money.”
For cleanrooms, flexibility comes in different flavors. Part of the key to planning flexibility in cleanroom settings is making them more adaptable — where you can conduct one form of research the current year and modify the cleanroom for another form of research down the road. “This is a much different type of flexibility than trying to perform significantly different types of research, with very different environmental requirements, in the same space on any given day, which can be very expensive,” says Weaver.
To account for flexibility, lab designers must ensure the systems themselves are adaptable over time to accommodate changes in program. In the NASA Langley cleanrooms, they have facilities that go up different tiers — Class 100,000 is the baseline and works up from there. “Just about any given lab/cleanroom in this facility can be upgraded to a higher level if it needs to be in the future without major retrofit,” says Weaver. Every lab/cleanroom module is set up to pick up an additional full module expansion in either direction and still provide the required outside air, power, etc.
Further reading: Can sustainable design be cost effective?
For the NASA Langley cleanrooms, AECOM chose an integrated fan-powered plenum module approach, which is a modular and scalable system in the ceiling that helps aid the flexibility of the space. The number of fan modules in the ceiling grid can be adjusted as needed to meet the level of cleanliness required within the space.
“Obviously with the lower levels of cleanliness there are fewer modules in the ceiling, but modules will be added at a later time if there is a change of program requirements,” says Weaver. The cooling coils can be integrated in the plenum for the fan-powered modules, and that way the recirculating air is tempered as it is recirculated. Local air recirculation through these modules eliminated the need for running large duct systems through the building between the cleanrooms and the penthouse.
The recirculated air is important to keep the cleanroom clean and keep the temperature controlled. “Recirculation isn’t a great idea if you are trying to get rid of chemicals and other hazards though,” says Weaver. “That’s why the balance really has to be well-kept to understand you don’t want to use this type of environment to manage hazardous chemicals.”
Goals and objectives for a research environment must also consider operations and maintenance, so that requirements can be properly set and attainable. What is achieved by collaborating with all stake holders during the early stages is a design that keeps the balance between offering a state-of-the-art facility and the building users’ and operators’ level of sophistication and capabilities. It is important to integrate with the users, engineers, scientists and the O&M staff right from the beginning. “Any combination alone won’t do it; everyone has to be involved,” says Weaver. “In this case we started with the research scientists and management, then really dug deep into the operations and maintenance, and incorporated the ideas of those who are going to be operating the building over time.”
Cleanrooms and labs are energy-intensive spaces, with significant opportunities for improved efficiency. The avenue AECOM took with the NASA Langley cleanroom spaces was clear programming to prevent creating overly clean spaces due to their high and also clear programming of spaces that require a 100 percent outside air approach.
“Obviously every cubic foot of air pulled out of the facility must first be brought in and tempered and cleaned,” says Weaver. “So it’s really a matter of trying to strike that balance for use. For example, we talked through all the areas that needed 100 percent outside air in the building, and what spaces could use recirculated air to reduce energy.”
The final plan consists of a transition between office spaces that can be highly recirculated air, certain lab space that can be recirculated, all the way down to those labs which must have 100% outside air. “Tiering, again, helps maintain energy efficiency where you can afford it, knowing you have some other areas that will be energy hogs,” says Weaver.
Once the process of minimizing energy intensive systems was completed, a series of energy conservation measures was implemented to minimize and capture waste energy, e.g., air-to-air heat exchangers; desiccant wheels; variable flow chilled water, hot water, and condenser water systems; high efficiency chillers; and an absorption chiller, utilizing nearly free and available high pressure steam on the campus.
The future of cleanroom flexibility/sustainability
Many vendors are making products and controls that will be key to enhancing flexibility and sustainability in cleanroom facilities, and many of these systems are getting so complex and subtle in terms of how they will react to the building and its technologies.
“We have been doing renovations in buildings that are 50+ years old, as well as new construction, and the key is to be able to say that, in 50 years, the lab will be able to be upgraded to accommodate the technologies that don’t exist yet, while operating now to maintain a tight level of control, whether it’s temperature, humidity, particulates or hazardous materials,” says Weaver. “Trying to be flexible in space design is the key to allowing the future to happen in the right way.”
Lindsay Hock is the Editor of Laboratory Design. www.labdesignnews.com