Page 130 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 11
THE EXPLORATORIUM
The seawater temperature averages about 60°F annually, varying 5°F higher or lower with the season. One requirement by the San Francisco Bay Regional Water Quality Control Board is that the seawater must be returned to the Bay within this range of temperature after it is used and must not exceed the highest temperature normally observed. To achieve this, the system introduces some evaporative cooling spray as it is discharged back to the Bay.
Water purity is another closely monitored metric for the seawater, both in the return discharge but also with regard to the seawater being pumped into the system from the Bay. This incoming seawater is filtered for organic material that might affect the equipment operation. There is also a filtration process to prevent small animals, particularly salmon fry, from being drawn into the system. To accomplish this, the design utilizes a type of filter that normally is used on fish farms. The advantage of these filters is that they work primarily by gravity and have a very low pressure drop compared with standard sand filters. The result is a much smaller size and lower energy use for the many pumps that are used in this system, another design choice that lowers the building EUI and contributes to the goal of ZNE performance.
Within the spaces, occupant comfort is maintained using 72 separate thermal zones, some of which may require separate heating or cooling compared to adjacent zones, a normal require-
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Zero Net Energy Case Study Buildings: Volume 2