Architecture at Zero 2016 is a zero net energy design competition open to students and professionals worldwide, engaging architecture, engineering, planning students and professionals in the pursuit of energy efficient design.
This year's competition was a student housing project on the San Francisco State University campus.
Channels: A Repository of Sun, Wind, and Water
The Channels residential complex site is located on the northwest corner of San Francisco State University campus, geographically defined by a submerged stream to the south and by Lake Merced to the west. Moist coastal winds and fog buffet the site and limit the peak solar resource potential to April, May, and June.
The building form of Channels is derived from systems dedicated to harvesting renewable energy from wind, sun, and water in order to approach the Net-Zero-Energy goal. The program – devoid of parking – is also intended to encourage the residents to pursue a sustainable lifestyle relying heavily on public transportation, bicycling, and the amenities of the surrounding neighborhood.
With 767 units, the residential complex is comprised of a series of stepped eight- to five-story bands that frame channels of park-like landscaping. The channels (or spaces in between the buildings) fan out from south to west, optimizing solar exposure and ventilation to energy-harvesting systems and to individual apartments.
Energy Harvesting Systems
Passive Energy Harvesting Systems wrap virtually every surface of the structures and the grounds framed by their footprints. These overlapping systems weave together and offer granular contributions to an aggregate energy pool shared by all units within the Channels complex.
The facade of the banded structures is characterized by the alternating rhythm of vertical garden boxes and 70° angled solar water heating panels, contributing heat to a closed loop system organized like a large thermosiphon. Natural convection assists modular water source VRF heat pumps to circulate the heated water from the panels to passive on-demand heating/ cooling units and hydronic heat exchangers in individual apartments. Multiple zones within a common living space maximize comfort and minimize heat energy waste with a high level of control.
Below grade, geothermal heat exchange is maximized throughout the 6.4-acre site with 100-foot deep underground piping arrays to absorb heat from the ground. An additional separate closed-loop system contributes to the collective heat reserves of the complex.
The roof is dominated by a point-grid of spiral wind turbines. Specifically conceived for urban environments, the helical design allows the individual units to collect wind energy from any direction. The horizontal plane of the roof also includes an array of solar-heated water panels to augment the solar gain strategy.
High-humidity fog condenses and collects within the garden boxes mounted on the exterior walls throughout the complex. The vertical garden softens the angular elevations, promoting the green theme and augmenting the R-value of the wall assembly. Storm water runoff and grey water are collected for irrigation of the garden channels.
Channels apartments promote the conveniences of high-density living within a sustainable, humane environment. The natural amenities of adjacent Lake Merced are extended within the framed open spaces that fan across the complex. Native, drought-tolerant plants like Limelight Bower Wattle, Yellow Sand Verbena, and Mock Heather line bio-retention swales that define the landscaping.
Outdoor play structures for children, exercise courses, and interactive art pieces all reinforce the active role that residents play in minimizing their daily energy consumption. The high level of sustainable design framing the living environment encourages a healthy lifestyle for families and single students alike.