When evaluating and reviewing food dehydrators, the below product features and functionality should be considered and compared across different units and brands. One way to compare different brands of food dehydrators, that contain similar features, is to evaluate the food dehydrators on a price per square foot of drying area (total price divided by total drying area) while also considering the brand, reputation and product reviews of the dehydrator units that are being considered.
You can evaluate different brands of food dehydrators, which have different product features, using the same price per square foot of total drying area and then personally decide if additional features are worth the extra cost per square foot.
o Total Drying or Dehydrating Area – How much space does the dehydrator have to dry food? The total dehydrating area is expressed in square feet and is calculated as follows: The product of a) the number of drying drays multiplied by the size of the drying trays (length by width in inches) divided by b) 144 square inches. As an example, if a dehydrator has 9 drying trays that are 15 inches by 15 inches each, then the total drying area equals 14.1 square feet (15 multiplied by 15 multiplied by 9 = 2,025, 2,025 divided by 144 equals 14.1). Obviously, the total dehydrating area determines how much food you can dry at one time. The total drying area should be adequate for the largest amount of food you will dry during a twenty-four hour period. As a rough rule of thumb, approximately one pound of food can be dried per square foot of drying area. However, this amount will vary depending on the type of food being dried, the thickness of the food slices and the food’s water content.
o Air Flow – Dehydrators remove moisture from food via heat and air flows. Food dehydrator air flows are designed either horizontally or vertically. Horizontal air flow food dehydrators have their heating element and fan located on one side of the dehydrator. The drying trays that hold the food are arranged like drawers inside the food dehydrator. Typically, horizontal air flow dehydrators are better at dehydrating different types of food at the same time as the horizontal air current mixes the food flavors less than vertical air flow dehydrators. Also, horizontal air flow dehydrators better prevent food juices from dripping down onto the heating element, thus making cleaning easier.
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.
A food dehydrator without a thermostat will dehydrate at a constant, unchanging heat, but at a potentially increasing temperature inside the dehydrator. This can cause case hardening; food with a dry outside but with moisture and potentially bacteria on the inside.
o Watts – The energy consumed or used by a dehydrator is measured in watts, similar to that of the light bulb. The watt power of a food dehydrator should be considered in relation to the total drying area. More drying trays and larger dehydrator dimensions should require more watts used by the dehydrator to ensure adequate food dehydration. You can compare the energy used or needed between different dehydrators by comparing the watts per square foot of total drying area. Simply divide the watts of the dehydrator unit by the total drying area to obtain the watts per square foot.
o Price – A good metric to compare different dehydrators that vary in size, total drying area, wattage and or price is to compare their cost per square foot of total drying area. To calculate, divide a food dehydrator’s cost by that unit’s total drying area.