Evaluation of heating performances and associated variability of domestic cooking appliances (oven-baking and pan-frying)

By comparison with those in industry, domestic cooking processes are rarely studied with respect to heat transfer although they can drastically modify the quality of heated products. In order to compensate for this lack of information in the literature, the aim of this work was to propose test procedures to evaluate the variability of domestic appliance heating performances in the case of oven-baking and pan-frying. The measurements included the continuous recording of pan temperature during pan-frying using different types of hobs (electric, halogen, gas, induction) and pans; the continuous recording of air temperature and measurement of the convective heat transfer coefficient and equivalent radiative temperature during oven-baking using different types of ovens. The results revealed broad variations in heating conditions depending on the type of appliance used and on consumer behaviour. For pan-frying, it was shown that pan temperature varied constantly during heating. From an initial value of 200 °C and a given product load, it could fall to 150 °C or rise to 330 °C at medium or high heat, respectively. For oven-baking, heating was sometimes performed at an actual air temperature that differed considerably from the air temperature set on the oven. These measurements also showed relatively low convective heat transfer coefficient values, ranging from 6 W/m2 K under free convection to 16 W/m2 K under forced convection.