2. Heat absorbing surface is always perpendicular to the sun-rays because of the cylindrical collector glass tube. Hence peak absorbtion always.: The collector fins and tubes being flat, the incident sun-rays will be at 90 degrees only at noon. So the peak absorbtion is also only during this time.
3. Vaccum inside the collector tube reduces heat loss at night.: Heat loss will be more in collector panels at night.
4. Negligible scaling of tubes –can be cleaned manually (Inner dia 37 min). Consequent loss of efficiency is minimum.: Heavy scaling of copper tubes which cannot be cleaned manually as bore dia is 12.50mm, causing substantial loss in the efficiency of the system.
5. Satisfactory performance in cold conditions .: Performance falls significantly on cloudy and winter days.
6. Increment in temperature from ambient temperature is 100c to 500c on clear sunny days.: Increment in temperature from ambient temperature is 100c to 400c on clear sunny days.
7. Advanced technology at a competitive price.: Outdated technology, high price.
7. Less area required for installation.: Unit occupies huge area.
8. Incase of collector tubes damage, tubes can be replaced individually.: Entire glass has to be replaced in case of damage, high cost for replacement.