||MT. AIRY, NORTH CAROLINA
The design of Mt. Airy Library successfully applies renewable energy technologies in a facility that calls for high illumination levels and humidity control in a region with hot, humid summers and cool winters. The library plan is organized around a circulation spine and main lending desk, from which the librarian can have visual control of the building. A saw-tooth clerestory above the structural bays provides daylight over the circulation desk, reading areas and reference stacks. A butterfly roof configuration with glazed ends and a central elongated light well provides illumination for the open stacks area.
Passive cooling in the building is achieved in a number ways. Shade trees and a light-colored roof membrane reduce the impact of solar radiation in summer. Operable windows allow for natural ventilation when the weather permits, and thick white colored masonry exterior walls provide the thermal lag necessary to delay the effect of the summer sun on the interior until the evening hours when the library is closed. Passive heating in winter is accomplished by storing the heat gained through south facing windows and clerestories in CMU walls, the concrete structural elements and the tiled concrete floor slab.
Computerized monitoring equipment has shown that the total energy use of the library is 23,149 Btu/sq ft/year. The library “uses about one sixth as much energy per square foot as a nearby municipal building .... compare that [23,149 Btu/sq ft/year] with a typical small office building’s 105,000 Btu/sq ft/year in a cold climate and 65,000 in a warm climate and you can see how frugal the Mt. Airy design is.” Solar Age Magazine.
“The daylighting design is a great success economically and visually. A typical commercial building uses about 20,000 Btu/sq ft annually for lighting. Mt. Airy used only 2,691 Btu’s/sq ft, a reduction of over 86 percent... The bottom line is that the daylighted Mt. Airy Public Library is a low-energy-use building that’s extremely attractive, aesthetically pleasing and that the people of Mt. Airy have declared, by their enthusiastic utilization of it, a runaway best seller.” Lighting Design + Application.
The Mt. Airy Public Library was the winner of an American Institute of Architects Design Award.