The main thrust of this paper is to develop a photovoltaic(PV) array area estimation model applicable to energy independent dedicated outdoor air system(DOAS) design. The proposed model was derived as a function of electrical load required to DOAS operation, tilt and azimuth angle of PV array and total incident solar radiation on a horizontal surface at a given location. The electrical loads of DOAS serving a high-rise apartment building with various unit sizes and numbers were estimated and a numerical model returning daily electrical energy consumption of a DOAS was derived. Total incident solar radiation on a horizontal surface at any given location were also estimated using an existing solar radiation prediction model. By comparing the results acquired from the proposed PV array area estimation model with an actual case found from open literature, applicability of the proposed model was verified. The predicated PV array area was very similar to that of the real case and would be used at the design phase of the energy independent DOAS.