Abstract :
Spandrel areas on south and west elevations of curtain walls on occupied office buildings in Summit, New Jersey and Rolla, Missouri were instrumented with sensor arrays that measured various microenvironmental conditions, including glass surface temperature, glass edge temperature, air temperature and relative humidity within the enclosed air space behind the spandrel glass panel and period of condensation on interior spandrel glass surfaces. Data were collected from May 1991 to May 1992. Microenvironmental conditions were more extreme in Rolla, where inside glass surface temperatures reached 82.1 °C (178.9 °F) in May 1991, despite the fact that thermal conditions at each site were moderated by the heat sink effects of massive concrete elements in the spandrel areas. Center-to-edge temperature differentials were sufficient to induce tensile stresses in glass panel edges of approximately 2000 psi (13.8 MPa). High humidities within the spandrel enclosures resulted in regular periods of condensation on inner spandrel glass surfaces.
