A test loop for thermal performance of flat plate liquid-type solar collectors has been designed and built according to the ASHRAE standard. The test loop has been placed on the flat roof-top of the KAIST building No.9 for the test to be carried out outdoors.
The main purpose of the present study is to reevaluate the ASHRAE standard for "Methods of testing to determine the thermal performance of Solar Collectors" and to examine if any modification or simplification of the ASHRAE standard is necessary to be adopted for Korean solar collector industry. For this purpose, a series of tests was performed using the test loop along with a typical solar collector fabricated by a Korean manufacturer : Results of the test for the thermal performance of a solar collector are presented and compared with the predictions of the existing theoretical model. The time constant of the solar collector has been determined experimentally and variation of the thermal efficiency of the solar collector with the angle of incidence between the direct sun rays and the normal to the collector aperature has been also examined. In addition, the thermal performance of the solar collector has been measured under the condition of lower solar insolation than the value recommended by the ASHRAE standard. Finally on alternative method of determining the thermal performance of solar collectors is recommended in this work.