Thermoelectric cooling has a high quality of temperature control compared to Vapor Compression Cooling. This paper presents a numerical and experimental study on the effect of the cold-side heat sink design and the operating condition of its fan on the performance of thermoelectric compartment of a hybrid demotic-refrigerator. The hybrid refrigerator had three compartments. One of them was cooled by thermoelectric cooling system. A 3-D lumped model was used to simulate the cold-side fan. In the experimental part, temperature at ten points inside the TE compartment was measured. The numerical results of temperature field and coefficient of performance of thermoelectric refrigerator were in good agreement with the measured values. Performance of the thermoelectric refrigerator was investigated using the numerical simulation in the states of: (i) varying the cold-side fan rotational speed, (ii) creating vertical slots through the cold-side heat sink. Width and number of slots were varied. Results showed that running the fan at a speed, 2000 rpm, was associated with 20% increase of COP relative to running it at 500 rpm. Using plate fin heat sink resulted in bad air distribution in the compartment. Generating vertical slots in the heat sink improved the temperature uniformity inside the TE compartment.