Concrete slabs and other high thermal mass building elements can be pre-cooled prior to occupancy. This reduces peak load and allows load shifting to off peak hours.
For example, the Gap Building in San Bruno, California (Architect - William McDonough, with Gensler; Engineer - Arup) uses a raised floor air distribution system, combined with a concrete floor slab to reduce peak loads. In the cool evening hours, outside air is brought into the building, while warmer air is flushed out through roof monitors (which also act as a source of daylight). This action drops the temperature of the thick concrete floor slabs to as low as 60 deg F. During the day, the cooled slabs absorb some portion of the heat produced in the building, which results in an estimated 20% reduction in peak loads, according to the designers. The system is so effective, the local utility gave the Gap rebates for this thermal storage system.
Visit William McDonough's Web Site on the Gap Building
Contents of this site are ©1999 - 2002 Christopher R. Schaffner
Last Update January 13, 2002