Numerical study on the influence of louver design on VRF system thermal performance in enclosed spaces in Erbil city

Abstract

Variable Refrigerant Flow (VRF) systems are extensively employed for space heating and cooling, especially in multi-story buildings where outdoor units are concealed behind aluminum louvers for architectural reasons. However, this common practice can compromise system performance, leading to inadequate heat dissipation, high suction temperatures, increased energy consumption, and a reduced coefficient of system performance. This numerical analysis study investigates the impact of louver tilt angle and opening ratio factors on VRF air conditioner performance when installed on building balconies. The study aims to optimize louver designs for concealing condensing units, enhancing performance, and minimizing power consumption. Two proposed louver designs with varying tilt angles and opening ratios were analyzed and compared with the existing design. Key findings underscore the importance of efficient heat dissipation for optimal refrigerant condensation and system efficiency. The study identifies the unintended ßtuck effectïn the current design, proposing optimal louvers with a 20° angle and a 60% opening ratio to minimize turbulent thermal plumes. Additionally, increasing the louver opening ratio to 80% is shown to effectively reduce air recirculation, optimizing overall VRF system performance. Comparisons with previous studies highlight local climate variations and operational differences, emphasizing the need for tailored louver designs for specific environmental conditions.