Ann Arbor’s 14,700 SF Branch Library in Pittsfield, Michigan.
Environmental Considerations:
1. Relationship to Site
The main space of the library faces south to capture the maximum heating benefit from the winter sun and maximum daylight throughout the year. The south wall is designed to admit maximum solar radiation in the winter but to block direct sun in the summer, admitting primarily indirect and reflected light. The north and west sides, those most exposed to winter winds, are service spaces and have minimal windows.
2. Building Cross-section.
The high, arching ceiling combined with the roof monitor serves to reinforce the natural tendency of warm air to rise, thus facilitating convective cooling. In the summer, air in the monitor is heated by the sun and is allowed to escape through operating windows on the north side. It is replaced by cooler air entering near the floor on the south side and, to a lesser extent, air entering from under the eave on the nor. In the winter, with the windows closed, the heated air in the monitor is pushed down by ceiling fans. Overhangs block the high angle summer sun but admit the lower angle winter sun.
3. Recycled Content Material
By way of example, the roof and much of the sidewalls are clad with pre-finished steel, made primarily from recycled material. The pre-finishing is with a low VOC content resin. The window frames are fabricated from recycled aluminum, and the carpet is woven with 50% recycled content yarn. The cellulose wall insulation consists of 90% recycled material, and the drywall will be a minimum 50% recycled content.
4. Low Energy Content Material
The masonry for this building is to be burnished concrete masonry units rather than brick. Not only is far less energy consumed in the manufacture of these units than is required for brick, but also they are manufactured less than 50 miles from Ann Arbor, and therefore a relatively small amount of energy is consumed in their transportation to the site.
5. Materials from Renewable Resources
Wood for construction and for the fabrication of furnishings will be from managed forests rather than from old-growth forest trees. For example, cork flooring is made from the bark of the cork tree, which is removed without damaging the tree and subsequently re-grows.
6. Coordinated and Efficient Lighting
The artificial lighting system will be automatically monitored so that it is turned on only when the day lighting is insufficient for comfortable reading. If the day lighting level rises, the lights automatically shut off. A built-in time delay prevents frequent cycling on and off. The light fixtures utilize highly efficient T5Ho lamps with electronic ballasts, and limited accent lighting is low-voltage halogen.
7. Air Quality Management
Most commercial buildings operate with a constant quantity of outside air taken in by the mechanical system whether needed or not for health and/or comfort reasons. The Branch will have sensitive air quality monitoring devices that will modulate the air intake so that the only outside air that is heated or cooled will be what is actually required at any given time.
8. Construction Practices
During construction, wood, plastic, and metal waste will be separated so that it can be recycled, thereby diverting at least 50% of the usual construction waste from the landfill.