Study on the performance of thermoelectric refrigerator under natural convection heat transfer condition

•The performance of the thermoelectric cooler is improved by reducing the number of legs and increasing the number of coolers.•A 3D model for thermoelectric refrigerator used under natural convection heat transfer condition is developed.•An experiment was carried out to validate the simulation.•The inside air temperature decreases as the fin height increases, but the cooling capacity and COP of the refrigerator change little.