Solar collector collects the heat by absorbing solar radiation. It is a vital component of solar dryer. Collector
efficiency depends upon design parameters such as collector material, absorber coating, and collector inclination and
environmental factors such as solar intensity, wind velocity etc. Collector efficiency is calculated for trial E1
throughout the day and given in Table 1. Efficiency was found to be minimum during the morning (at 10 a.m.) and
late afternoon (at 4 p.m.), and it was maximum at afternoon (12 p.m.). It is interesting to note that collector efficiency
is linearly related to the solar intensity and wind velocity. From 11 am to 2 pm efficiency remains nearly constant
(around 25%), as solar intensity and wind velocity does not vary appreciably during that time.