A computational model has been developed to simulate the temperature cycles of the freezing and fresh food compartments in a household refrigerator. Modeling consists of two parts coupled with each other: a refrigeration system and a temperature cycle of the refrigerator. The refrigeration system including a compressor, a condenser, an evaporator and a capillary tube is modeled based on performance data measured or provided by the manufacturers. The temperature variation in the refrigerator during a cycle is simulated using the lumped capacitance method. The switching on and off of the compressor is controlled by using a given temperature band of the freezer with the highest temperature for the compressor turning on and the lowest one for turning off. The thermophysical properties of the cabinet of the refrigerator such as the thermal conductance of the walls and heat transfer coefficients on the walls of the cabinet are approximated by a combination of measurements and theoretical calculations. Numerical simulations were carried out for the thermal performance of a 19 cubic foot top mount refrigerator. The model predictions of temperature are validated against the experimental data. The effect of cross ambient temperatures from 21.1 °C (70 °F) to 32.2 °C (90 °F) on the performance of the refrigerator is reported.