California Academy of Science: D+H Provides the Solution for Complex Ventilation and Climate Control of the Building Complex

     (Photo: http://photos.prnewswire.com/prnh/20131023/648179 )

Founded in 1853, the California Academy of Science has been
one of the favorite destinations for visitors to San Francisco for generations. As the first natural history museum of its kind in the world, it combined an aquarium, planetarium, exhibition areas and research institutions under one roof. In 1989, an earthquake completely destroyed the building centrally located in Golden Gate Park. It rose again on September 27, 2008 after around ten years of planning and construction under the leadership of the Italian star architect Renzo Piano. Though the new building abuts the old ground plan, it follows a completely new architectural and didactic concept. It cost San Francisco488 million dollars, which was raised in several ways, including the largest fundraising campaign in the city's history.

The new California Academy of Science-CAOS for short-consists of two buildings, each with approximately 27.43 m high, free-standing glass domes that house the planetarium and the living rain forest. A glass-covered piazza covering 183 square meters and approximately 1,160 square meters of variable exhibition space lies in between. While inside the glass-covered ceiling and facade elements in the piazza provide visitors with a view into Golden Gate Park, the outside of the building looks just like part of park from a bird's eye view. This is due to the fact that a majority of the roof areas comprise a green roof covering about 10,118 square meters occupied by 1.7 million native plants. According to Renzo Piano, the CAOS is intended to integrate into the scenery of the park like a gentle rolling hill and to use its striking domes to invoke the feeling of the seven hills that San Francisco is famous for. The dependence on organic structures extends to the entire rolling roof structure made from curved steel beams with a span of up to 29 m, which carry the concrete roof. The development of the fully glass-covered piazza proved to be just as challenging. Measuring approximately 22 x 30 meters, the gently curving roof is supported by a dual network of steel beams, bolted together by horizontal braces. The triangular glass surfaces each have an edge about 1.83 m long and follow the dimensions of the underlying steel frame structure, giving the structure the multi-faceted appearance of an insect eye.

The design dimensions and allusions are impressive by themselves. The ecological and climate-controlling innovations are even more impressive. CAOS informs its visitors not only using the exhibits about nature, but also by setting the standard regarding natural and sustainable building. German expertise quickly comes into play here, because the pool of options quickly shrinks when it comes to experts in advanced natural ventilation systems. D+H Mechatronic AG from Hamburg stood out during the tendering process for developing the corresponding window and facade systems, which were installed by Gartner Metallbau from Gundelfingen, Germany. The task was to ensure complete climate control and ventilation technology without using primary energy sources whenever possible. Though the CAOS does have integrated floor heating and cooling systems, these are only used in exceptional cases. That became possible due to the intelligent use of natural air flow that appears due to different dimensions of the curved roof constructions, domes and facade elements. This is how Gartner installed 720 ventilation drives on the frontal glass facade alone. These were developed by D+H specifically for hard-to-reach windows. The drives are connected to the building control center and thus react to all internal and external climate data. The 40 controllable round roof flaps provide natural ventilation and climate control on the two domes over the rain forest and the planetarium.

Along with the performance of D+H system solutions from drives and control elements, the quality and durability of the made-in-Germany technology speaks for itself. For cool weather, a system of matched opening angles now provide for continuous background ventilation of the CAOS building complex without unpleasant drafts. For warm weather, small and large ventilation angles combine to ensure that excess room heat is extracted as quickly as possible. High-lying ventilation flaps remain open at night and use the cool weather at night for cooling if it was hot on the previous day. In addition, the ventilation sequences are controlled by the room temperatures, humidity of the air and the wind conditions. If, for instance, the CO₂ concentration reaches a critical value during high visitation periods, ventilation intensifies automatically. The windows close when it is raining, foggy or extremely windy. The result of the intelligent natural ventilation concepts also impressed the U.S. Green Building Council this October, who awarded CAOS with LEED Platinum, the highest possible accolade. The use of renewable energy through solar elements, the high potential for saving water and the use of recycled material were assessed alongside the approximately 34 percent savings in energy usage through natural ventilation systems, heat recovery and shade.

Text and image data is available for download at http://www.dh-partner.com in the "News" section. We look forward to receiving a specimen copy if used
for publication.

D+H Mechatronic AG
Georg-Sasse-Straße 28-32
D-22949 Ammersbek
Germany
Phone: +49-40-60565-0
Fax:   +49-40-60565-222
[email protected]
http://www.dh-partner.com