Fig. 3. Position of thermocouples in the solar tunnel dryer
2.2 Materials
Andrographis paniculata has been used for centuries in China, India, and Thailand to successfully treat upper respiratory tract infection, fever, sore throat, herpes, and an array of other infectious and chronic diseases. Therefore Andrographis paniculata is chosen to investigate the performance and then compare data with natural sun drying. The performance tests were carried out two times during June, 2011 and weight 100 kg of Andrographis paniculata were used for each test. In the morning, cut Andrographis paniculata were manually loaded into the product containers to be dried and the fans were started at the