A window-type air conditioning system includes an outer housing having an indoor compartment, an outdoor compartment, and a water tank, a fan assembly, a compressor unit, an evaporator unit, and a water cooling unit. The water cooling unit includes a pumping device provided in the water tank, a top water collection basin for collecting the cooling water from the pumping device, a fill material unit provided underneath the top water collection basin, a bottom water collection basin provided underneath the fill material unit, and at least one heat exchanging pipe immersed in the cooling water. The cooling water collected in the bottom water collection tank is arranged to be guided to flow back into the top water collection basin, while a predetermined amount of refrigerant is arranged to flow through the heat exchanging pipe for performing heat exchanging process with the cooling water.