Power saving in a central air conditioning system by using multiple PCMs integrated with fresh air path

Abstract

Decreasing the fresh air temperature before entering the air conditioning (AC) system will have a significant influence on reducing domestic power usage. To obtain a low fresh air temperature, the current work highlights a numerical investigation of an air-phase change materials (PCM) heat exchanger (H.EX.) with AC systems using ANSYS software. The heat exchanger was divided into several cells filled with multiple PCMs (RT-22, RT-24, RT-26). Throughout the day, the outside air passes through the system to decrease its temperature. Also, the PCMs are discharged by the low ambient temperature during the night. A numerical model was established and validated with experimental results from the literature and got a good match. The influences of multiple types of PCMs, outlet air temperature from the system, and the reduction in the cooling coil power were investigated. The outcomes concluded that multiple PCMs have a significant impact in decreasing the fresh air temperature before entering the AC system, compared to a single PCM. The fresh air temperature decreased from 45, 42, and 39 °C to roughly the values of 33, 32, and 31 °C, respectively, by using the air-PCM H.EX. The cooling power decreased by 11.76, and 11.17 % at the fresh air temperature of 45, and 39 °C, respectively, compared to the system without air-PCM H.EX. The proposed design is suggested to integrate with the AC systems.