The building’s white color implies clean energy, but the inspiration for the shape of the mansion came not only from pictographic characters for sun and moon but also evokes a sundial, a timepiece that indicates the daylight hours by the shadow that the gnomon casts on a calibrated face.
The building’s white color implies clean energy, but the inspiration for the shape of the mansion came not only from pictographic characters for sun and moon but also evokes a sundial, a timepiece that indicates the daylight hours by the shadow that the gnomon casts on a calibrated face. The triple symbols hint at the march of time and the urgency of energy replacement.
Many of the energy-saving technologies in the Sun-Moon Mansion have been used in Beijing’s “Bird’s Nest” (National Stadium), an iconic Olympic venue. Since its steel framework is similar to that of the larger structure, it is sometimes referred to as the “Solar-powered Bird’s Nest.”
From Light to Power
The uniquely-shaped Sun-Moon Mansion attracts visitors day or night. After sunset, its photovoltaic-powered LED-defined arcs and angles make a fascinating silhouette.
The mansion’s two sections both deploy a glass structure whose transparency makes it possible to see the sky from the atrium lobby. Such a design traps heat and captures the best natural light. The top layer of glass is inlaid with black BIPV (building integrated photovoltaic) modules, which serve three purposes in one: power generation, light emission, and energy conservation. The two buildings have 180 module sets, enough to power their neon lights at night with enough to spare to contribute to the power-collection grid. The curtain walls, doors and windows of the mansion also adopt BIPV modules – high-performance battery chips that convert light into electricity.
Presently the building has five photovoltaic power generating systems connected to its power grid, which, in addition to supplying the building’s exterior illumination, also provide power for roof lighting and sun-shading. They produce 30,000 kwh of electricity annually.
The cost of photovoltaic power generation is very high, however, so photovoltaic power generation is only subsidiary according to Lu Xiurui, a member of the Himin Group’s Technical Department. The mansion’s main power supplier is its crown of solar energy thermal collection tubes. No doubt the roof is the scene-stealer of the mansion, and also the embodiment of its identity as a green building. To support the large area of solar heat collecting tubes, the mansion has adopted a steel frame similar to that of the “Bird’s Nest” in Beijing. The difference is that the mansion’s steel structure is only 1 percent of that used by the “Bird’s Nest.”
The Largest Solar Air-conditioner
No air-conditioners are visible on the mansion’s sun-exposed south wall. Instead its windows are shaded with shutters and eave-like devices, part of an intelligent sun-shading system. The building uses solar-powered air-conditioning for 45 percent of its refrigeration needs, saving 60 percent of the energy consumed by conventional refrigeration. And the sun-shading system further cuts the building’s power demand for cooling and heating.
According to a Himin spokesperson, this air-conditioning system, independently developed by the group, is the largest solar-powered air-conditioning system in the world. In summer it uses solar heat to drive refrigerators, and in winter for heating devices; in transitional seasons it supplies hot water for daily use. Himin can now demonstrate its prowess at designing large-scale air-conditioning systems and set a good example for other companies to follow.
Making full use of multiple energy-saving approaches, the mansion has broken the long-standing barrier to reducing the huge energy consumption common in conventional buildings.