System performance of split type a/c units in high-rise residential buildings with different condenser arrangements

Abstract

The split-type air conditioning (A/C) systems are widespread due to their high flexibility compared to the centralized A/C systems in high-rise residential buildings, especially in the tropical region. As the condensers are placed in the restricted space in building re-entrants, poor cooling, malfunction, and energy wastage are common issues faced in these high-risers due to the heat column formation. The induced hot-air plume creates elevated temperatures in higher floors adversely impacting the energy efficiency of condensing units. The strength of the heat plume and the temperature rise depend on several factors including condenser arrangement, shape and size of the re-entrants, and air-conditioner loading conditions. Hence, the present study focused on analyzing the heat column generation using CFD and evaluating the group performance of the condensers with the different condenser arrangements using the performance indices such as GCPR, GCCR, and GCER. The results revealed that the group power performance of the split A/C units could be increased by 105% compared to the existing condition if the condensers are located within 1.5m from the exterior wall. Furthermore, the indices provided direction to set a design guild-line to develop an energy evaluation procedure for the different types of arrangement of condensers.