Both heating and drying can be done with solar assisted heat
pump. A detailed review of studies conducted on SAHP systems
is given in Table 1. As it can be seen from the table, SAHP systems
have been evaluated under three groups, water heating, space
heating and product drying, respectively. Drying is extracting liquids
in a matter. At the technical drying, external interference is
applied to the drying process and the moisture in the matter is extracted
in various methods. Thus, drying is described as reduction
of product moisture to the required dryness values at a definite
process [16,17]. In the world, 97–98% of dried vegetables that
made traded dry with hot air under controlled conditions. The factors
that affect drying rate are air temperature, air velocity, product
type, moisture content of the product, thickness of product, method
of drying, temperature moisture diffusivity and drying kiln
structure. Although mushrooms are fresh consumed vegetable, it
increasingly is consumed as the dried product in recent years
[18]. Dried mushrooms, packed in airtight containers can have a
shelf life of above 1 year [