1814C Under what conditions is the efficiency of a flatplate

18–14C Under what conditions is the efficiency of a flatplate solar collector maximum? Compare maximum efficiencies of unglazed, single-glazing, and double-glazing flat-plate solar collectors. Which one has the highest maximum efficiency? Why?

Solution

In the morning period, efficiency is maximum when compared to afternoon. Reason is incident energy is maximum during morning.

2) Less heat losses give higher efficiency.

3)Higher mean temperature gives higher efficiency.

Double glazed flat plate collector has maximum efficiency.

Reason:heat gaining capacity is maximum for double glazed flatplate collector.Temperature also high for double glazed flat plate collector.