Unlike earlier studies, this study examines six refrigerants with various properties using the same rooftop air conditioning system of a building to evaluate performance. Performance metrics such as cooling capacity, energy consumption, temperature, and pressure were calculated. Laboratory testing of a rooftop air conditioner with R410a was performed to validate the simulation program's predicted data. Six distinct refrigerants' carbon emissions in two different scenarios were calculated using the Life Cycle Climate Performance technique, which was evaluated for environmental studies. These experimental tests were carried out at temperatures of 20 °C, 25 °C, 30 °C, and 35 °C, respectively. Maximum discrepancies between simulated and experimental results for cooling capacity, energy consumption, and energy efficiency were calculated to be 2.8%. The study found the lowest value in the R1234yf carbon emission at 51.30 kg CO2e. The highest cooling capacity was 154760.34 W in R454b, and the lowest cooling capacity was 76949.94 W in R1234yf. The highest EER value was 3,018 in R454b, while the lowest released was 2.257 in R22. The SEER value was 4.101 for R32 and 2.298 for R1234yf. The simulations concluded that R410a, R454b, and R32 refrigerants have superior cooling capacities.