Page 28 - Zero Net Energy Case Study Buildings-Volume 3

CASE STUDY NO. 12 THE J. CRAIG VENTER INSTITUTE
(Previous page) View of main entrance. (Courtesy of ZGF Architects)
(Opposite page) View of court- yard with Office wing on the right and Laboratory wing on the left, with solar photovoltaic support structure above. (Courtesy of ZGF Architects)
Building Envelope
The exterior walls and roofs conform to California energy standards in effect in 2010, which required R-19 walls and R-30 roof construction. Standard tapered roof insulation under a single- ply membrane and fiberglass batts in the walls were used. The walls were framed with 6” metal studs, but no continuous layer of rigid insulation was used to prevent thermal bridging because it was determined not to be cost effective given the mild climate year-round.
Daylighting and Electric Lighting
By locating all the office space in a separate wing of the building, its design could be optimized for daylighting. The narrow width of the floor plate and the maximum height of the windows al- lowed for deep penetration of daylight in the entire space.
The placement of the solar photovoltaic panels on the supporting structure over the courtyard was carefully designed to permit ample daylight to enter the south-facing windows, which were recessed to prevent direct glare from the sun. This was analyzed for several spacing options using daylighting software. (See image below.) This eliminated several rows of panels but was deemed necessary for the energy savings that would result from good daylighting plus the obvi- ous preference to have the courtyard be daylight-filled and not cavernous. The structure was extended further to the west to make up the difference.
The electric lighting system was designed with T5HO lamps throughout. LED products were not cost effective at the time of design, only a few years ago. At the appropriate time in the future, the electric lighting will be replaced by the much more efficient LED technology.
The laboratory wing is also open to daylight on both sides. With higher than normal ceilings made possible by the elimination of the typically large air ventilation ducts (see the HVAC discus- sion below), daylight zones in the lab bench space are possible.
(Below) Daylighting analysis of office wing and laboratory wing for study of opening geometry of solar photovoltaic panel array over the central courtyard. (Courtesy of Inte- gral Group)
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Zero Net Energy Case Study Buildings: Volume 3