HR: 1340h
AN: A43B-1150    [Abstracts]
TI: Using Surface Energy Balance Calculations of Rooftops to Generate Energy Efficient Buildings
AU: * Khosla, R
EM: rkhosla@uchicago.edu
AU: Frederick, J
EM: frederic@uchicago.edu
AB: Individual structures within the same urban region can experience different micro-scale (<10³ m) climates as a consequence of their particular physical characteristics and surroundings. The energetics of these urban microclimates at length scales of individual structures are determined by a combination of different energy flux components that individually act to cool or heat the roof surface: long wave radiation, short wave radiation, sensible heat, evaporative cooling, leading to heat conduction into or out of the surface. In an analysis of rural and urban microclimates within the Chicago region, a semi- empirical energy balance model is used incorporating radiative and meteorological measurements to parameterize annual and diurnal variations in energy fluxes statistically. The temperature of the surface is determined by solving the heat conduction equation within the thickness of the building roof using a first principles mechanistic model. This allows comparisons of results between various surface types and microclimate conditions. Results show that the microclimates of the structures and modifications of surface and thermal properties influence their surface temperatures, adjacent air temperatures, and consequentially are shown to influence the heating or cooling loads throughout the year. Variations of these properties can significantly influence the distribution of energy amongst the fluxes acting on the roof to minimize heat conduction into the building, making them more energy efficient and also reduce the heat island effect.
DE: 1610 Atmosphere (0315, 0325)
DE: 3307 Boundary layer processes
DE: 3359 Radiative processes
DE: 3399 General or miscellaneous
DE: 6334 Regional planning (1880)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting