Page 48 - Zero Net Energy Case Study Buildings-Volume 1

CASE STUDY NO. 2
STEVENS LIBRARY AT SACRED HEART SCHOOLS
(Right) View of portion of roofscape consisting of solar photovoltaic panels laid flat and tubular skylights.
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PHOTO: EDWARD DEAN
final nod toward the impact on energy use of the occupants’ perception of their thermal comfort, slow-moving ceiling fans were installed to augment the perception of air movement. The comfort conditions produce by this air movement allows for higher temperature setpoints for cooling.
Plug Loads and Special Loads
Occupancy sensors combined with ENERGY STAR® rated equipment supplied to the building users reduces the amount of plug loads in this building. The intensity of computer use with this user group is less than other types of buildings; nevertheless, even with the energy efficient equipment and sensors, the plug load is still a sizable part of the total electric load in the building.
This building also included a system of pumps for the building’s rainwater collection system that feeds the irrigation system and a gray water system that collects water from all the buildings on the quad and treats it adequately so that it can be used to flush toilets in all buildings. As a shared system, the gray water pumps could be partly excluded from the accounting of energy use for the library alone, particularly as solar photovoltaic panels are added to the other buildings and the entire energy demand/supply accounting becomes a campus rather than an individual building calculation. For this case study, however, all of the measured pump energy is included in the final building performance charts. (The project is still a net producer.)
Controls
The control systems in the building are basically self-contained, where all the controls are inte- grated into each component and are programmed at the factory. The specific package unit cre-
Zero Net Energy Case Study Buildings: Volume 1