Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Civil and Environmental Engineering


Dr. G.A. Kopp


To assess the wind induced pressures on an array of solar modules mounted parallel to the roof surface of a low-rise building, wind tunnel studies were conducted on an array on a 1/20 scale building model with either a flat roof or a 30° roof slope. The spacing between individual modules, G, and the mounting height above the roof surface, H, were studied. Large G yielded improved wind resistance by lowering the external peak suctions and peak net suctions. Large H beyond a small cavity depth was determined to be detrimental for wind resistance as the peak external and net suctions were higher in magnitude. The pressure equalization coefficient, Ceq is utilized to quantify the change in the peak net wind pressure from the peak external pressure as values can be approximated as a single curve when plotted against G/H for a given tributary area. Roof and array edge effects caused by flow separation were noted to increase the magnitude of the suctions on modules around the perimeter of the roof surface and array. The bare roof interior and edge zones for low-rise buildings were noted to be appropriate to capture the effects of building-induced flow separation. The array edge zone was approximated as ≈ 1(H + t) to 2(H + t) around the perimeter of the array. A design factor, γ, was developed and is intended to be applied to codified external pressure coefficients. It is a function of the roof zone, the array zone, A and G/H.