This research presents an in-depth evaluation of a liquid-flooded compression (LFC) air-conditioning system for hot climatic conditions through integrated energy, exergy, economic, and environmental (4E) analyses. The system incorporates an oil injection loop and a regenerator to enhance compressor thermal management and refrigerant stability. Three working fluids (i.e., R410A, R32, and R290) were investigated under uniform boundary conditions. The findings revealed that the LFC configuration significantly reduced compressor discharge temperatures, with R32 showing the largest reduction compared to the baseline vapor compression system. All refrigerants achieved higher coefficients of performance (COP). For a representative Kuwait case study, the LFC system reduced peak electricity demand by up to 21.5 % and annual energy consumption by 14.2 %. The economic evaluation demonstrated payback times within 6 years for all refrigerants. The LFC system lowered total equivalent warming impact (TEWI) up to 8.42%. Among the tested refrigerants, R32 demonstrated the most well-balanced operational characteristics (COP of 5.97 to 6.49, ˙ Itot of 1.83 to 2.10 kW), whereas R290 attained the lowest exergy losses and exhibited the most favorable environmental profile.
