Smith Research Facilities Highlight Complexity of Lab System Designs
September 01, 2001
Appeared in Lab Animal
The Dana Farber Cancer Institute (DFCI) in Boston, Massachusetts has opened a new 440,000-square-foot research facility that is intended to be the cornerstone of its cancer research program -- the Richard A. and Susan F. Smith Research Laboratories. The state-of-the-art building was designed to support the institute's rapid expansion by providing additional research laboratories and animal holding facilities.
The new laboratory center features animal holding/breeding spaces, common core equipment rooms, washing/sterilizing facilities and two floors of tenant-allocated lab space fitted out for specific research needs. Other project elements include below grade parking, multi-media conference and training spaces, office areas, and generic wet labs. The facility cost $80 million to build, with $25 million allocated to sophisticated mechanical, electrical and plumbing work.
In development of the new animal holding facility DFCI goals were to create a stable, comfortable environment for animals as well as a safe working environment for staff. These key elements needed to be satisfied to meet the institute's research objectives. The design of mechanical and electrical systems provided DFCI with the required control and system flexibility to satisfy the environmental and safety requirements for animals and staff. The mechanical systems also provide protection for the outside environment by filtration of exhaust air.
The animal facility sets new standards in mechanical, electrical, plumbing, security and fire protection design, with features such as humidity and temperature controls, variable frequency drive controlled air supply and exhaust, air filtration and tight space pressurization control. These are found within an extremely energy efficient, easily maintained and flexible mixed-use design that is capable of meeting the environmental needs of all the building's users. In many cases the building's standards exceed applicable building code and American Association for Accreditation of Laboratory Animal Care requirements.
Complex Air Handling Systems Required
One of the key design issues was to provide a stable 30% Relative Humidity (RH), environment at temperatures of 72 degrees. To accomplish this, three different air handling systems were analyzed in terms of cost, space requirements, humidity range, energy efficiency and temperature.
The first, a conventional air handling unit, provided almost no reliable humidity control, producing air with an RH ranging from 20 to 70%. The second, a conventional air handling unit with a direct expansion coil (DX) and reheat capability, included a better humidity level control. The DX coil in this unit removes the moisture from the air stream and deposits byproduct on the coil, thus requiring a hot gas bypass loop to defrost the coil. It was found that during defrost periods the humidity could not be controlled unless a stand-by unit is provided. Nor could the system maintain humidity levels below 72 degrees.
Further research led to a liquid dessicant dehumidification system, which uses a chemical spray to continuously remove moisture from the air stream. The byproduct of this system is processed after it leaves the unit to remove the water from the solution. The system is completely controllable, can maintain humidity levels below 30 degrees and, though it is more expensive initially, is the most energy efficient to operate. After reviewing the manufacturers' test results to ensure that traces of the liquid in the airstream would pose no threat to the animals, a liquid desiccant system was selected for the project.
Because the new building is in a dense urban area, extra steps were taken to insure indoor air quality. These began in the parking garage, where variable frequency drive starters on the exhaust fans were controlled by carbon monoxide monitors. This ensured an adequate fresh air supply without sacrificing energy efficiency.
All air supply to the animal floors is HEPA filtered. In the animal holding rooms, the HVAC system provides 18 to 20 air changes per hour. Most animals are living in vented racks with ducted exhaust and HEPA-filtered room air supply. Biosafety cabinets in the laboratories have 30% exhaust to the outside and 70% air recirculation. All fume hood and biosafety cabinet exhaust are VFD controlled to protect the researchers who use them.
Throughout the facility, air handling systems are zoned on a floor-by-floor, quadrant-by-quadrant basis serving like areas, to minimize disturbance to adjacent areas. In the laboratories the mechanical, electrical and plumbing systems follow a modular concept, to allow easy maintenance and modification.
Creating an Isolation Area
A central design task was creating a BSL-3 (biosafety level) barrier to protect the animals within the high risk negative barrier suite and positive barrier suite from their surrounding environment. In doing so, the design had to meet not only National Institute of Health guidelines but also the more stringent requirements of independent testing agencies and the institute's own in-house safety department. Solutions included providing HEPA filters on supply and exhaust air, eliminating floor drains, air tight seals on utility penetrations through walls, and a space pressurization monitoring system.
Waterproof gaskets were specified for light fixtures and switches, and all valves, junction boxes and fittings that required access were located outside the rooms. Air tight dampers were used in the supply and exhaust boxes, while bubble tight dampers were specified for the exhaust duct.
Finally, the system that tracks and monitors air flow at the supply and exhaust boxes was connected to alarms which annunciate at the facility director's computer as well as at numerous local alarm panels located strategically within the suite. Fume hood ventilation alarms also annunciate at multiple locations.
The lighting system in the animal holding areas had to accommodate the animals' hibernation and sleeping cycles in addition to the schedules of researchers, animal handlers and the cleaning staff. This was accomplished through the installation of a multi-level, energy-efficient fluorescent lighting system. Recessed 2' x 2', 3-lamp fluorescent fixtures were provided with dual electronic ballasts to provide 30, 60 or 85 foot candles as needed.
Two lamps in each fixture are wired to a programmable time clock on a dedicated switch, to automatically turn the lamps on or off as facility procedures dictate. Light settings can be altered when necessary by using the timer and the override on the astronomical clock. To make sure lights aren't left on when someone leaves the room after retrieval or cleaning, the third lamp in each fluorescent fixture is wired to a separate timer switch which automatically turns the fixture off after a preset period of time.
The freezers, refrigerators, hoods and selected outlets within each room are supplied with emergency power from an emergency electrical closet, to a maximum of 1.75 watts per square foot. Other electrical details include gasketed, washable wet location fluorescent fixtures in the washrooms, dedicated electrical panels for the PBS and ABC suites, and the inclusion of amply-sized bus duct risers in each electrical closet with space allocations for future connections.
One challenge was to provide a code-compliant, UL approved Audio Visual fire alarm device that wouldn't harm the research animals. Standard fire alarm horns operate between the frequencies of 500 and 1200 hz. The facility manager's research indicated that frequencies above 470 hz might be harmful to the animals. A device manufactured in England specifically for use around animals was located, but it was not UL approved. To use a 500 hz device that sounds a temporal code -- pulsed alarms of short duration -- on the animal floors, a variance was need from the Boston Fire Department. This solution was approved by the institute, which felt the short exposures would not cause the animals harm.
Designing for Flexibility
Because the needs of researchers change with each new grant obtained, it was extremely important to build flexibility into the research areas. The adjustable dehumidification system, zoned air supply, modular lab layouts, plug-in bus duct risers, strategically located plumbing stacks and extra air capacity all work toward that goal. As scientists began moving into the building in the summer of 1997, these features made it easy to tailor lab space to specific research programs.
The success of the project depended on early and continuous coordination between the architect, engineers and owner. The owner had to select and prioritize from its wish-list and make its expectations clear; the design team had to meet those expectations within the limitations of budget and space; and the engineers had to present equipment and system options that could meet the specified performance and maintenance goals.
This last item was an ongoing process, aided by an enthusiastic animal facility representative who made it her business to be well informed about available options and to fully understand their relative benefits and drawbacks. Not least of her considerations was the issue of maintenance, and whether the facility could provide the staff, training and money that various equipment options required.
The efforts of the parties paid off: the completed Richard A. and Susan F. Smith Research Laboratory ably meets the specialized needs of the researchers who work there. In doing so, it sets new standards for laboratory design which may prove useful to future researchers seeking to advance the cause of medical science.
Mark Yakren, P.E. is a senior vice president and Susan Kessler an associate partner with Syska & Hennesy, the mechanical and electrical engineer for the Smith Research Laboratories at the Dana Farber Cancer Institute. The project architect was Shepley, Bulfinch, Richardson and Abbott.