Description and Testing of a Non-Evacuated 1.5×CPC Collector Thermal Performance Comparison With Other Collector Types

Abstract

A 1.5 × non-evacuated CPC type concentrator is described and tested. The results obtained can be summarized by F ′ ηo = 0.673 ± 0.001 and F ′ U = (2.64 ± 0.041) W/m2 ° C. The early average performance of the concentrator is calculated and compared with the performance of two other collector types at constant operating temperature: a selectively coated regular flat plate and an evacuated tube type collector. It is shown that the concentrator performs better than both the flat plate and the evacuated tube collector for constant operating temperatures for 35° C to 100° C in a climate like the one in Lisbon. The three collectors are also compared operating in two systems: (1) DHW in which they all deliver comparable yearly average amounts of energy, and (2) IPH at 95° C (process return temperature = 65° C) in which the flat plate delivers ∼30 percent less yearly energy on the average in comparison with the other two which behave very much in the same way. The 1.5 × low cost is discussed in comparison with the other two collector types, establishing the concentrator as an excellent choice for hot water heating applications.