In order to study the performance of nanofluids as the working
fluids in the solar collector system, each experimentwas performed
four times and the good datas were chosed to analyze. Fig 7 shows
an example of typical recorded data for water and nanofluids
(Cu:25 nm, 0.1 wt%) at 140 L/h in one of the test days. The inlet fluid
temperature is almost remain unchanged, the outlet fluid temperature
is the critical parameter.