The hospital is being delivered as a progressive design build project, with tk1sc, a WSP company, playing an important role in a highly collaborative process to encourage and facilitate innovation. The client’s original intention was to reduce natural gas usage as much as possible, but we suggested going one step further and seeking to eliminate all natural gas on the project; a proposal that excited both us and the client. Our approach was therefore to avoid the use of fossil fuels entirely and implement electrification throughout the hospital, including heating, domestic hot water and steam systems for humidification and sterilization, combining all the equipment and functions in an approach that has not been used before.
This is the first University of California medical center with an all-electric powered central utility plant; and as the first all-electric hospital of this scale for the client, this project broke new ground. Indeed, since there was no existing data to draw upon, we performed significant modelling, made innovative estimates and established numerous firsts. Excitingly, this means this project has the potential to be used as a case study for future engineers.
For this facility’s all-electric central utility plant (CUP), WSP had to completely rethink the standard HVAC cycle of absorbing energy from the occupied space and rejecting it to the outdoors. The operational goal of the CUP was to use heat recovered within the CUP process to generate heating of the facility and domestic hot water. Our engineering approach had to focus on balancing energy when we could, adding energy when needed, and rejecting energy only if we had excess. To achieve these goals, several design considerations had to be closely explored such as considering heating water load profiles, cooling load profiles, quantifying excess or deficit energy and how to apply air-side economizers. The team developed sequences of operations for efficient energy and equipment use. A whitepaper is available with more details.
To add to the complexity of the project, California is a seismic zone with strict codes to observe which, due to the acute nature of the hospital, meant that all the equipment needed to be seismically certified. Additionally, since it is essential to the safety of patients that the equipment functions without interruption, the authority having jurisdiction required it to be backed up by a generator system. Furthermore, we had to contend with California’s undersized electrical grid, which lacks the capacity for the electricity required for this equipment.
