Manufacturer focus: Designing labs, research buildings
Labs and research facilities house sensitive equipment and must maintain very rigid standards. Two manufacturers provide insights.
Rick Hermans, Applications Director, Daikin McQuay
Victor Neuman, Health Care/Lab Engineer, Schneider Electric
CSE: What tools or knowledge do engineering schools need to provide young engineers in order to successfully specify or design systems for labs?
Daikin McQuay: Engineering schools must provide students with the fundamental physics, psychrometrics, thermodynamics, and heat transfer knowledge as it applies to HVAC in general. Architectural engineering schools provide more practical skills in how to put HVAC systems together in concept for laboratory applications, specifically with respect to ventilation and the relationship between hood exhaust, make-up air, and static pressure control.
Schneider Electric: I started in lab design in 1983 when I was hired by the visionary lab planner Earl Walls, who passed away in the last year. He was a proponent of lab "modularity." The only constant of scientific research is change. Teaching modularity in design allows laboratory building to adapt to changes in the building which are needed to account for advances in scientific methods.
CSE: What are some common missteps that engineers might make on a laboratory project? Any tips you can provide?
Schneider Electric: In lab pressurization control, there is a common misstep of locating the variable air volume (VAV) duct with its pitot flow sensors too close to the takeoff from or to the supply duct or exhaust duct. Flow accuracy of this pitot sensor is not crucial in office buildings but it is vitally important to laboratory pressurization controls. While more accurate sensors are recommended, if you are using pitot flow sensors in your lab, it is imperative that there be at least three duct diameters of straight duct at the inlet of the pitot and one duct diameter of straight duct at the exit of the pitot flow sensor. Many engineers feel that straight duct is not necessary when using venturi valves. However, our work with commissioning agents have made us very aware that even with venturi valves it may be required to have a length of straight duct for the commissioner to insert a removable pitot tube in order to certify the venturi valve's performance.
Daikin McQuay: Too many designs are overly complicated. They use exotic equipment and controls when more simple designs will suffice. Labs are special, to be sure, but they can be solved with simple designs that are understandable, effective, and efficient. One tip would be to pay attention to the building envelope, especially the interior walls which are critical elements in maintaining static pressure control between spaces.
CSE: Please describe a recent lab project you’ve worked on—share problems you’ve encountered, how you’ve solved them, and aspects of the project you’re especially proud of.
Daikin McQuay: One past project was interesting and instructional from an academic perspective. The lab spaces were laid out in 10-ft modules with moveable partitions. The ventilation had to be flexible to accommodate various future revisions of lab space along these modules. The solution was a common vertical plenum space which served both as an air recirculation corridor and a utility corridor with connections of utilities in the same 10-ft intervals.
Schneider Electric: Schneider Electric recently completed a major animal breeding facility in Asia that was particularly complex. The engineer had specified that the entrance airlocks to each major animal holding room were to have five cascading pressure levels. This was accomplished to everyone's satisfaction with a cooperative effort of the consulting engineer, owner, commissioning agent, and Schneider Electric as the building automation provider. In addition, the system was required to monitor and log pressure readings at each point every second.
CSE: When designing a lab that is part of a multi-use building (such as in a hospital or university building), what unique challenges do you have?
Schneider Electric: The challenge in a university lab is balancing the open environment of a university with the security needed for scientific research. Scientists appreciate large open plan labs, but this is a challenge when planning the airflow containment and pressurization control.
Daikin McQuay: If a lab is not a single, purpose-built structure, you are constrained by the architecture of the other functions in the building. Since labs have unique ventilation requirements, you spend a lot of time trying to accomplish those ventilation designs in an architecture not meant for them. The most obvious of these is the fume hood exhaust system.
CSE: Describe your involvement in a recent integrated project delivery (IPD) lab project or research facility.
Daikin McQuay: The role was as owner’s representative. The duties were to write requests for proposal and to assist in the selection of the IPD team members, negotiating the common contract, and providing owners input on the design development. Since the lab was so unique that neither the owner nor the design team had ever done one before, the design process was a journey of discovery that couldn’t have been accomplished with any other project delivery process.