Performance of Small Commercial AC System with R-32 Applied for Educational Building in Tropical Country: A Thermodynamic Simulation
I Nyoman Suamir (1,a), I Wayan Adi Subagia (1,b), I Dewa Made Susila (1,c), Ketut Bangse (1,d) and Adi Winarta (1,e)

1) Mechanical Engineering Department, Politeknik Negeri Bali, Campus Street, Kuta Selatan, Badung, Bali, 80364 Indonesia
Author Emails
a) Corresponding author: nyomansuamir[at]pnb.ac.id
b) adisubagia[at]pnb.ac.id
c) dewamadesusila[at]pnb.ac.id
d) ketutbangse[at]pnb.ac.id
e) adi.winarta[at]pnb.ac.id>

Abstract

A numerical evaluation on the performance of a small commercial AC system with R32 as the refrigerant is presented. The evaluation is specifically applied for educational buildings in Bali Province, Indonesia. A digital model was developed in a standalone computer program U.CoolS V.1.12 which was established in the EES (Engineering Equation Solver) program. The digital model has been validated using data specified by AC manufacturers and then it was used to perform digital evaluation of the AC system based on ambient temperature of the Bali Province, Indonesia. Effects of condensing temperature in the condenser and evaporation temperature of the refrigerant in the evaporator on the compressor efficiency and AC system energy consumption were simulated. The evaluation results showed a strong influence of condensing temperature and evaporation temperature on the compressor performance and overall energy consumption of the split AC system. It was found that for 1 degree C increase in condensing temperature, the compressor power increased quite significantly around 2.1 percent, the cooling capacity of the split AC system decreased by 1.8 percent, COP and EER also decreased by 3.9 percent. For 1 degree C increase in evaporation temperature, it was found an increase in compressor power consumption of around 0.31 percent, an increase in cooling capacity of 4.4 percent and an increase in COP and EER of 4.1 percent. The results of this evaluation also showed that the split AC system performance using R290 refrigerant has a very good COP range from 3.27 to 5.95 with the implication that R32 refrigerant has the potential to be a refrigerant for the small commercial AC system.

Keywords: Energy performance- small commercial AC system- digital model- educational building

Topic: Engineering