Today, the need for cooling and cooling technologies are growing fast and they are used in many areas. On the other hand, saving energy and using the cooling systems more efficiently are major concerns in today's growing energy needs. Increasing the condenser capacity is one of the way of improving household refrigerator efficiency. In this study, first the performance test of a natural circulation wire-tube condenser was tested. Then the condenser was placed into a tank and 2.5, 5, 7.5 and 10 liters of melted vegetable oil was filled into the tank. Performance tests of the system were performed at both loaded and unloaded conditions as intermittent operation. A domestic refrigerator was run for 2 hours as intermittent operation for each scenario. All measurements (pressure and temperature) were taken at 5 minutes intervals. Experimental results showed that as the amount of oil in the oil-cooled condenser increases, the condenser capacity and cooling capacity also increase, and also the energy consumption of the system decreases. The energy consumption in unloaded operation of air-cooled condenser for 1 hour was measured as 90 Wh, and it decreased to 35 Wh for oil-cooled condenser filled with 10 liters of oil. The COP of the system in unloaded operation of air-cooled condenser was calculated as 2.23 and the energy consumption was about 90Wh. However, The COP of the system in loaded operation of oil-cooled condenser was increased to 2.81 and the energy consumption was decreased to 35Wh. On the other hand, the COP of the system in loaded operation of air-cooled condenser was measured as 2.14 and the energy consumption of it was about 95Wh. But, the COP of the oil-cooled condenser in loaded operation raised to 2.84 and the energy consumption reduced to 40Wh.