The present paper discusses a experimentally validated 3-D CFD analysis of the flow and thermal processes in a laboratory drying oven with a forced air circulation. The device is mainly used in the food and chemical industry to store products at a constant, spatially uniform temperature. The existing device has been assessed according to a certification procedure and then numerically simulated on the basis of the mathematical model developed, including all heat transfer modes, temperature-dependent air properties and local heat transfer coefficients on the external walls, etc. Furthermore, parameters such as the rotational speed of the device fan, the effectiveness of the distribution gaps and the rate of heat generated in the electrical heaters have been tested to improve the temperature uniformity within the chamber. Finally, several changes of the device configurations, such as the location of the heaters, the fan and the fan baffle, have been considered. As a result, the temperature uniformity has been significantly improved, which was also confirmed in the experimental test of the modified prototype. (C) 2009 Elsevier Ltd. All rights reserved.