Resilience in the built environment involves reducing, adapting to, and mitigating risks. It refers to designing buildings to absorb the shocks of short-term disruptive events or long-term stresses while delivering optimal facility recovery. These shocks and stresses can be natural or human-induced and may include droughts, hurricanes, floods, earthquakes, pandemics, and chemical spills.
Seismic activity is a special concern for the West Coast of the United States and Canada. British Columbia’s Provincial Health Service Authority (PHSA) wanted their new 640,000 square foot Teck Acute Care Centre (TACC) designed with stringent “post-disaster” resilient features, including an absolute energy target and three days of potable water storage.
Reducing a building’s energy demand has long-term cost benefits and decreases the amount of fuel storage needed during the loss of power from the utility. To meet PHSA’s goals, AEI designed an advanced heat recovery system consisting of water-to-water heat recovery chillers, air-cooled heat recovery chillers, and air-source heat pumps mounted within the warm exhaust air to boost efficiency. The heat recovery is then used as the first-tier building heating and domestic water pre-heat.
District hot water and campus steam are the second and third tier, respectively, supplemental heating sources. The mechanical plant and the air-handling system is sized for 100% outdoor air operations with 15% additional capacity. This allows for future clinical or long-term temperature changes.
Calculating and planning for domestic water storage
The governing codes and standards did not have a calculation methodology for potable water storage. AEI looked to the California Office of Statewide Health Planning and Development (OSHPD) standard for acute care facilities, which requires 50 gallons of potable water storage per day per inpatient bed. Reducing the daily water demand decreases the amount of water storage needed during the loss of water from the utility. AEI designed the plumbing system to use 35% less water than the LEED baseline building. The mechanical plant consists of all air-cooled or water-to-water heat recovery equipment so there is no demand from a cooling tower, further reducing the building’s water storage requirement. An additional water savings strategy included chilled water effluent cooling on the sterile processing autoclaves. The waste heat from the effluent is also captured by the heat recovery system.
The domestic water storage design consists of two tanks that hold a day-and-a-half worth of water and can be refilled with pumper trucks.
Under normal operations, water from the public utility continuously flows through the tanks to prevent stagnation and includes a side-stream chlorination system. The owner also required 24 hours of sanitary sewer storage, and the building has two tanks with pipe connections so pumper trucks can remove waste.
Continuing care during a disaster
Other resilient design features include six pandemic outbreak patient wings, a three-lane mass decontamination shower, and an active smoke control system. When activated, the pandemic outbreak patient wings switch to negative pressure, the air-handlers switch to 100% outdoor air, and a conference room at the entrance to the wing can double as an anteroom. Drop-down curtains in the ambulance bay canopy can be used to quickly convert the area into decontamination showers. The active smoke control system allows for individual smoke compartments to be pressurized during a smoke event. This allows procedures to continue and ICU patients to remain in place during an event without the loss of heating and cooling airflow.
The building is the second phase of the BC Children’s and BC Women’s Redevelopment Project and is an important milestone in the renovation and modernization of the facility, serving the needs of British Columbia’s most seriously ill children and most complex obstetrical cases. The facility includes single-occupant patient rooms, medical/surgical inpatient units, an emergency department, medical imaging and procedural suites, a hematology/oncology department, and a pediatric intensive care unit, as well as a high-risk labor and delivery suite and a neonatal intensive care unit. TACC was designed to meet LEED Gold certification requirements.
About the Author: Sean Lawler, PE, LEED AP
Mr. Lawler is a Project Manager and Mechanical Engineer at Affiliated Engineers, Inc., and specializes in the design of research and healthcare facilities. He has a passion for solving design challenges analytically and collaboratively, which has proved valuable on his many integrated project delivery teams. Sean’s design focuses include advanced heat recovery, steam systems, fuel systems, and specialty exhaust systems. He enjoys the daily opportunity to learn, share, and lead high performance and resilient engineering design. Contact Sean Lawler.