Numerical simulation for thermal distribution of air-conditioner outdoor units

Abstract

Air-conditioners used in high-rise residential or office buildings often have outdoor units installed on the sidewalls or roofs in the confined space of the buildings. The heat released from the outdoor units causes the temperature rise in the confined installation space and leads to uncomfortable thermal environment and deteriorative performance of air-conditioners. The factors affecting the performance of air-conditioners are the heat released from the outdoor units, the solar radiation and the ventilation of the confined installation space, which are investigated in this study and simulated by FLUENT using the porous model and discrete ordinates (DO) radiation model. It is proved that the porous model is more reliable than the solid model. The optimal installation distance from the supporting wall is obtained. The average temperature of the exit without wind is 1.18% higher than that with wind. The results show that the heat released from the outdoor units and the ventilation of the confined installation space are the main factors affecting the thermal environment in the confined installation space. The influence of the solar radiation is negligible.