To design this solar dryer for mango slices, preliminary experiments were first conducted with fresh mango to determine the drying behavior of the fruit and the corresponding demand placed on the drying system. Fresh Tommy Atkins mangoes were manually cut and oven-dried at 50°C for 96 h to determine initial moisture content. Isopiestic drying procedures were employed to determine water activity of fresh mango by storing triplicate samples of 3 mm thick slices in desiccating jars of known relative humidity. Equilibrium moisture contents were determined on samples taken from dessicator jars containing MgCl2 (32.8%), NaBr (57.6%), NaCl (75.3%), and KBr (81.8%). Triplicate samples were also taken from storage under the ambient relative humidity of the lab. The temperature and relative humidity of the lab were recorded with an Onset® Temperature and Relative Humidity Data Logger (HOBO® H08-003-02, Bourne, Mass.) on an hourly basis. Samples were weighed once daily and equilibrium conditions were considered to have been reached when three consecutive measurements were within ±1mg. Samples were then removed from the jars to undergo standard oven drying procedures.