Mercy Hospital’s new $93 million, 310,000-sf West Lakes facility was the first Greenfield Hospital in Iowa to achieve LEED Certification. A feasibility study, using energy modeling, compared alternate systems to meet LEED requirements. The building infrastructure system is estimated to save 25% over ASHRAE 90.1 guidelines. The system includes a sub-cooling chiller for the surgery area tied to emergency power for added redundancy, VFD’s on the chillers, variable speed pumping, RTU’s designed with lower air tunnel velocities to reduce overall fan horsepower, and special acoustical housing for the RTU’s to eliminate the need for duct silencers, thus reducing pressure drop of the air system and overall horsepower of the system.

The seven-story, 146-bed structure was designed for future horizontal expansion, so a standalone central plant was designed consisting of 1,100-ton chiller and 800 BHP boiler capacities. The central plant is connected to the main hospital structure via an underground tunnel. Emergency power is provided by a 1,500 kW emergency generator. Utility metering was provided for all the electrical, gas, and water utilities.

During the early stages of design, the size of the facility was increased by the owner; however, the project budget remained fixed, requiring significant effort by the design team and owner to find solutions to meet the budget and provide a LEED certified facility with flexibility for future growth.

Additional features include low flow plumbing fixtures to save over 30% of associated water consumption, a specialized atrium smoke control system and stairwell pressurization system, and energy efficient lighting. Significant energy savings were realized by streamlining the building lighting system. Lighting energy loads were designed for 30% below the applicable IECC code. Implementation of substantial daylight harvesting, occupancy controls, and automatic dimming of patient room corridors further improved performance.