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 air.
• 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 water system.
• 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 administration spaces.
• Waste heat from laboratory equipment is transported to a heat recovery chiller, then routed to a domestic hot water preheat system.

Labs21 Connection:

Integration of laboratory HVAC system with the medical areas HVAC system:
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 system:
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.

Biographies:

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.

Education:
Bachelor of Science, Mechanical Engineering, Oregon State University

Registration:
Mechanical: Oregon, California, Idaho, Washington, Kentucky, Colorado, South Carolina

Professional Affiliations:
American Society of Heating, Refrigerating & Air-Conditioning Engineers

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.

Education:
Bachelor of Science, Mechanical Engineering, University of Portland

Registration:
Mechanical: Oregon

Professional Affiliations:
American Society of Heating, Refrigerating & Air-Conditioning Engineers
American Society of Mechanical Engineers
American Society of Plumbing Engineers
National Fire Protection Association

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