Sarah Cannon Cancer Hospital Sets Standard for Sustainable Health Care Design

Sarah Cannon Cancer Hospital tower is doing more than providing critical health care services in Plano, Texas. It’s doing it with groundbreaking sustainability features that have been recognized with a milestone achievement for medical facilities.

Recently, the U.S. Green Building Council designated the four-story hospital with its Leadership in Environmental and Energy Design (LEED) v4 Gold certification – the first hospital to achieve this level of certification. It also becomes only the second health care project to earn LEED v4 certification, and the first certified in Texas.

WSP USA was part of the team assembled by the owners, HCA, and the architect, Perkins + Will, to make this breakthrough environmental achievement possible. WSP provided the mechanical, electrical and plumbing (MEP) engineering, as well as telecommunication, access control design and construction administration for the new patient and burn intensive care unit (ICU) building. Collaborative partners for the project included JE Dunn Construction, The Brandt Companies, Enterprise Solutions, SSR, Baker Triangle, ClayMoore Engineering and L.A. Fuess Partners.

“Plano is considered one of the fastest growing areas – not just in Texas but also in the entire U.S.,” said Jessica Navarro, principal-in-charge and project manager for WSP. “This increased populace requires an increase in capacity of institutions that can provide health care.”

The $110 million facility, located on the Medical City Plano campus, has 138,000 square feet of space and 90 patient beds, with additional operating and recovery rooms.

The new tower includes 30 specially designed burn and trauma ICU rooms on the third floor that can provide emergency treatment in the event of a mass casualty event that results in multiple serious burn injuries.

“These rooms are designed to accommodate the specific temperature control requirements to keep the rooms 70-100 degrees Fahrenheit, and with varying levels of humidity,” said Luis Reyes, mechanical engineer for WSP. The team used radiant heat panels over the beds to control the temperature in the required range, while also providing comfort conditions throughout the room.

Construction on the hospital began in August 2017 and the building was opened for patient care in late October 2019. Since its opening, the building has been analyzed, determining that its sustainable features functioned as anticipated to meet the thresholds required to earn Gold certification.

HCA had challenged the project design team to incorporate an integrated project delivery model in order to satisfy three major goals for the project:

• reduce the overall budget and time of construction by 10 percent,
• use pre-fabrication elements as much as possible, and
• complete the commissioning of all new systems and spaces in the building before opening the hospital.

The resulting building met those expectations. “It is designed to save 678,000 gallons of water per year above standard water use for a facility of similar size, through efficient landscaping/irrigation and plumbing systems,” said Ryan Collins, plumbing engineer for WSP.

During construction, more than 95 percent of construction waste was recycled or reused and thereby diverted from landfill disposal.

“This means that 880,000 pounds of potential construction waste was kept out of the landfill,” said Amit Bhansali, lead mechanical engineer for WSP. “Prefabrication was a contributing factor that resulted in less on-site waste.”

By incorporating early design involvement with all sub-contractors, the MEP design team was able to collaborate in the pre-manufacture of MEP racks. Most MEP elements were manufactured offsite in a controlled environment and transported to the building for installation.

“Electrical conduits for distribution were constructed offsite that were to go underground and brought to the site and lowered to the location where the electrical equipment was to sit,” said Brandon Macha, electrical engineer for WSP. “The process that traditionally would have taken a few days to complete if assembled at site took less than two hours.

“This avoided the risk associated with weather events, of which there were many,” Bhansali said. “As a result, the project remained on schedule and overall labor cost was reduced.”

Additional materials and finishes throughout the project were selected for sustainability, including responsible sourcing of raw materials, life-cycle effectiveness, and use of healthier, low-emitting content that promotes improved indoor air quality.

The building was designed to be 26 percent more energy efficient compared to the energy code, creating a potential $112,000 annual savings in energy costs for the medical facility.

To help achieve this level of energy reduction, WSP’s mechanical design team designed the building cooling and heating system to be more than 21 percent efficient than the baseline set by ASHRAE 90.1-2015.

The chilled water system consists of magnetic bearing chillers, which consume less energy per ton of cooling load than a standard centrifugal chiller and can operate at lower condenser water temperatures.

“The ability to work at colder condenser supply temperature up to 36 degrees Fahrenheit allows the chillers to basically act as a heat exchanger at those conditions with relatively low energy expense of refrigerant migration,” Bhansali said. “The operation at low condenser water temperature provides a smaller lift for the compressor in the chiller, and thus is significantly more efficient.”

One innovation introduced by the team was the concept of cooling the condenser water temperature further than the cooling tower limits by using a heat recovery chiller that rejects heat simultaneously to the building heating hot water.

“The heat recovery chiller is designed to carry the full heating load for the building throughout the summer months for reheating purposes using the heat from condenser water,” Reyes said. “Thus, helping the building to stage the boilers off.”

The building heating hot water return is passed through a water-to-water heat exchanger before it reaches the heat recovery chiller. The hot water return is then used to preheat the domestic cold water prior to entering the domestic water boilers that serve building hot water.

To ensure that the systems do not generate excessive noise that would potentially disrupt neighbors, the design team was tasked with engineering a solution to mitigate sound of the external cooling towers and indoor generators, as the new building was located only 60 feet from the property line.

The engineering team measured the ambient sound level before construction and reviewed the sound data from the manufacturers for cooling towers and generators. The team then worked with acoustic vendors to provide sound attenuators for intake and exhaust for generator air. Special low-speed fans were chosen for cooling towers to reduce the noise level while not compromising the capacity.

Steps were also taken to add sound massing on internal walls for the generator room to reduce overall sound levels, resulting in a sound level that was below the local ordinance requirements.

This successful LEED v4 Gold design of this project is serving as a template for several other WSP medical tower projects, two of which are currently in the design stage.

“HCA wanted this project to be the foundation for its collaborative approach on large scale projects,” said Jeff Black, senior vice president at WSP. “Thus, there was lot of involvement from all consultants, trades and anyone who touched this project and that provided a lot of opportunities to grow for everyone.”

One reason this project was special to the WSP design team was because of the unprecedented challenges that came with it.

“Health care projects are always rewarding regardless of their size because you know that you are making a difference in the community and providing better venues of care for those in need,” Bhansali said. “But creating something that was not just state-of-the-art, but groundbreaking for sustainable medical building design, took this project to a whole new level. Anyone who worked on this project grew both personally and professionally as a result of the process.”

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