Vertical air flow dehydrators have their heating element and fan located at the base of the dehydrator. The drying trays that hold the food are stacked on top of the base. Because the drying trays and food are stacked on top of the heating element, drying temperatures can vary between the top and bottom food drying trays. Vertical air flow dehydrators may require a swapping of top and bottom drying trays, during the dehydrating process, so that an even drying effect is achieved across all the food and drying trays.
o Thermostat – A thermostat is a device used to regulate the temperature of a heating or cooling system so that the system’s temperature is maintained near a desired, chosen amount. A thermostat does this by switching heating or cooling systems on or off, as needed, to maintain the desired temperature. A food dehydrator’s adjustable thermostat should have a good range of drying temperatures, typically 85 to 155 degrees Fahrenheit, to handle different types and amounts of food.