Case Study: Integrating a biomedical research laboratory
into a medical office building
John McMichael, PE, and Jeffrey
Welter, PE, Interface Engineering Inc.
The Oregon Health & Sciences University (OHSU) River Campus
Building #1 is a 16 story high rise mixed use building located in
the South Waterfront development in Portland, Oregon. The building
houses medical wellness space, ambulatory surgical space, medical
office space and biomedical research space. The building will be
linked to the main OHSU campus via an aerial tram. This, along with
three levels of underground parking provides convenient access to
the building. A multitude of innovative energy and water efficiency
strategies are applied in the building to help meet the goal of
LEED V2.1 Platinum certification.
The presentation will focus on complexities faced in integrating
laboratory systems into the building smoke control system, medical
spaces HVAC system, lighting control system and membrane bioreactor
system. Integrating the laboratory HVAC system with the medical
spaces HVAC system presented unique opportunities for energy savings
without imposing capital cost penalties.
- Prescriptive outside airflow rates required by health codes,
plus the airflow ratio of 4:1 between medical space vs. laboratory
space, provided a source of clean conditioned air to the laboratory
HVAC system, thereby avoiding the cost of conditioning 100% outside
- The building membrane bioreactor system was able to accept laboratory
acid waste without negative ramifications to the biological treatment
agents, allowing recycling greywater back into the water closet
flush system, cooling tower makeup water systems, and building irrigation
- A combined general exhaust and fume hood exhaust system allows
maximum discharge plume height. Since the combined exhaust system
participates in the floor-to-floor smoke pressurization system,
DDC controls must selectively open/close terminal air valves to
maintain fume hood exhaust systems as the remaining exhaust capacity
is managed for strategic building pressurization.
- Integration of the laboratory HVAC system and lighting systems
with joint space motion detectors allows turndown of lighting and
airflows during unoccupied hours while still allowing local occupied-mode
use of spaces.
- Communication between the Phoenix control system and the Alerton
Building Automated System (BAS) allows use of air valves for "trimming" control of laboratory space pressurization relative to adjacent
- Waste heat from laboratory equipment is transported to a heat
recovery chiller, then routed to a domestic hot water preheat system.
Integration of laboratory HVAC system with the medical areas
Laboratories are typically provided with 100% outside air for the
purposes of ventilation and space conditioning. 100% outside air
is most often a byproduct of the need for 100% exhausting of spent
laboratory air. This building includes 2 floors (approx. 27,000
sq. ft.) of biomedical research laboratory space nestled between
two adjacent floor groups (approx. 260,000 sq. ft., 11 floors total)
of surgery and medical office space. Separate supply and exhaust
air systems serve these two areas of the building. Prescriptive
health codes require minimum total and outside air flow rates to
various medical spaces, resulting in a prescribed ratio of outside
air to supply air for the medical spaces HVAC system. Since the
general exhaust from these medical spaces was considerably less
than the outside air inflow, a quantity of relief air is always
rejected from the building.
This design channels that relief air to the laboratory HVAC intake
air stream, resulting in approximately 40% outside air to the laboratory.
Direct mixing of the relief air stream with outside air is employed,
resulting in 100% energy recovery. 100% exhaust is maintained throughout
the laboratory in the form of fume hoods, biological safety cabinets
and general exhaust inlets.
Laboratory acid waste system connection to the membrane bioreactor
The membrane bioreactor is an onsite self-contained sewage processing
system. The system receives all waste streams from the laboratory
and from the medical spaces of the building. The waste stream is
processed with biological agents and filtration, then discharged
as Level 4 reclaimed water for water closet flushing, cooling tower
makeup water, irrigation water and eco roof cooling water.
Combined fume hood and general exhaust system:
The system combines exhaust streams from fume hoods, biological
safety cabinets and general exhaust ceiling inlets into one discharge
air stream. Two fans are sized at 50% each, with stacks adjacent
to each other to maximize plume height when both fans operate. Both
fans are constant volume machines to maintain plume height above
the building. The exhaust system is variable volume, utilizing rooftop
makeup air dampers at the fan inlets to maintain full fan volume,
thereby avoiding conditioning of excess air. Laboratory airflow
is reduced from 14 air changes per hour (AC/HR) to 4 AC/HR in general
laboratory spaces during unoccupied hours, allowing one fan to remain
off line during these periods. Three ancillary fume hood and hazardous
exhaust systems are routed to the main exhaust fan stacks to form
a combined plume to maximize plume height. Terminal airflow devices
are strategically controlled during operation of the building smoke
control system to maintain fume hood airflow while supporting floor
by floor pressurization.
Integration of lighting control with HVAC terminal airflow devices:
Motion detectors are distributed throughout the laboratories to
control lighting and terminal airflow devices. During unoccupied
hours, lights are turned off and the HVAC system is reduced to minimum
airflow. Biological safety cabinet airflow is maintained at 100%
flow, fume hood monitors generate alarms when sashes are left open,
and general exhaust and makeup supply air is reduced to maintain
a minimum 4 AC/HR or necessary makeup air flows, whichever is greater.
Zoned motion detectors allows local energizing of lighting and HVAC
terminals during unoccupied hours without bringing the entire laboratory
space on line.
John McMichael, PE, began his engineering career with Interface
in 1982 and now serves as a Principal for the firm. His 22 years
of experience include feasibility studies, HVAC and plumbing systems
design, hydraulic calculations, and energy analysis. John has extensive
experience working on housing, municipal facilities, military installations,
medical and educational facilities, manufacturing plants, office
buildings, and other commercial projects. He has designed award-winning,
energy-efficient mechanical systems and has experience with the
study and design of cogeneration systems and thermal storage systems.
His projects have included leading-edge technologies for new structures
and traditional applications for historical renovations.
Bachelor of Science, Mechanical Engineering, Oregon State University
Mechanical: Oregon, California, Idaho, Washington, Kentucky, Colorado,
American Society of Heating, Refrigerating & Air-Conditioning
Jeffrey Welter, PE, has been working
in the engineering profession since 1995, focusing primarily on
health care and laboratory facilities. As a professional engineer
at Interface Engineering, he is responsible for the technical design
and the management of multiple projects. He has a thorough understanding
of HVAC systems, plumbing systems and medical and laboratory gas
systems relating to health care facilities and laboratory facilities.
A background in HVAC installation lends beneficial perspective to
the design process.
Bachelor of Science, Mechanical Engineering, University of Portland
American Society of Heating, Refrigerating & Air-Conditioning
American Society of Mechanical Engineers
American Society of Plumbing Engineers
National Fire Protection Association
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