may dry food much faster than some air driers. Some solar driers can achieve higher food drying temperatures than some air driers. However, direct sun drying can chemically alter some foods making them less appetizing. Food drying is an excellent solar energy application since food drying primarily requires heat, and solar radiation is easily converted to heat. A clear or translucent glazing allows sunlight to enter an enclosed chamber where it is converted to heat when it strikes a dark interior surface. Airflow is typically achieved with natural convection (warm air rises). Adjustable venting allows regulation of airflow and temperature. Solar food drying is effective and practical in most of the populated places of the world. A general rule is that, if you can grow a successful vegetable garden, then there is enough solar energy to dry the food you produce (some overcast, northern maritime climates are the exception). Some solar food dryer designs employ a separate solar collector to generate the heated air, which is then directed into a food chamber or cabinet. This type of solar food dehydrator is called an indirect solar dryer. Other designs combine the collector and food cabinet and allow direct heating of food (these are called direct solar dryers). It is said that the indirect dryers allow much better drying, but the downside is their larger size. Backup electric heating can be incorporated into some solar food dehydrators to provide an alternative heat source if the weather changes. Solar food dehydrators are often cited as viable tools in the search for agricultural sustainability and food security. See also List of dried foods References Food preparation appliances Dried foods