Performance Evaluation of Solar Dryer Systems

Technical performance of a solar dryer is necessary to be evaluated to compare it with other dryers in order to assist users in identifying suitable dryers, to assist manufacturers in improving design, and to make prediction of its performance under different conditions. However, there is no single standard test procedure for evaluating the performance of solar dryer. This is mainly due to variations of construction materials, design, operating conditions of solar dryers. Besides, consumer preferences and interpretations of quality may vary

Leon et al., presented a review of existing evaluation methods and the parameters generally considered for evaluation of solar food dryers. The parameters generally measured and reported, in the evaluation of solar dryers, can be classified as : (i) physical features of the dryers; (ii) thermal performance; (iii) quality of dried product; (iv) cost of dryer and payback period. In addition to existing parameters, Leon et al. proposed a new evaluation parameters.

 a. Features of Physical of dryer

-   size, type, and shape

-   dryer collector area,  and solar dryer aperture

-   capacity for drying

-   drying tray area

-   convenience for loading and unloading

-  easiness for cleaning, maintenance convenience  handling

b. Performance of Thermal

-  drying rate or drying time  

-  efficiency of dryer

-  temperature of drying air

-  the maximum of temperature for

-  air flowrate

c. Quality of dried products

-   quality of color, flavor, taste, texture and aroma (so called sencory quality)

-  nutritional attributes

-  capacity of rehydration

-  uniformity of drying