Page 49 - Designing for Zero Carbon - Case Studies of All-Electric Buildings

MAKERS QUARTER BLOCK D OFFICE BUILDING
CASE STUDY NO. 2
Natural Ventilation
It is the year-round ideal climate of San Diego that permitted the principal energy-efficient design strategy: natural ventilation. Control of the natural outdoor air flow through the occupied spaces provides the basis for cooling comfort for almost the entire year. Block D has the ideal orientation to facilitate this air flow, namely a narrow lot with the long east and west exposures. The build- ing therefore captures cooling ocean breezes from the west and provides outlets for the cross- ventilation on the east sides of the slender office suites.
The cross-ventilation was aggressively designed with the introduction of overhead sectional ga- rage doors on each office floor, which open the indoor office space directly to the outdoors in several distributed locations. On the west side, the office space connects directly with the large common balcony areas that are sheltered from the western sun by large movable sunscreens. These shaded and protected outdoor areas are used by the tenants as part of the regular work space, useful in this manner for much of the year.
For those rare times when heating or cooling is required, the garage doors and openable win- dows must be closed for the HVAC system to operate. Conversely, when outdoor air conditions warrant, the building management system (BMS) automatically opens the windows and shuts off the HVAC system to allow cooling with the outdoor air. User-controlled ceiling fans can be operated to increase indoor comfort conditions by providing additional air movement, especially when the natural ventilation is necessarily restricted.
It is noteworthy that the tenants are informed about the design and operation of the building energy systems and features, with instructions about how to maximize comfort while minimizing energy use. The tenant leases include some language to this effect, specifying when certain operations may or may not be done. In addition, the plans for the tenant improvements (TI) are reviewed to ensure that nothing is done to counter the operation of these systems. Tenants are encouraged, for example, to locate partition walls in the direction of the cross-ventilating air flow and to avoid placing them where they will block this air movement.
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(Left) Natural ventilation was designed using cross-ventila- tion created by the use of sec- tional garage doors, five per floor. (Photo: Basic Agency.)