AbstractA solar test collector has been designed for the testing of thermally absorbing coatings under controlled conditions. The design consists of a collector fed by a controlled temperature fluid within the range of 25–90°C (77–194°F). This temperature is maintained by a custom electronic controller. A small variable flow pump circulates water through three collector pipes at selected flow rates. Strip heaters coupled with a differential temperature controller compensate for edge losses associated with small collectors. Detailed design and operation data are presented and three black chrome and one non‐selective absorber are analysed in detail by test collector measurements. Results show that efficiencies as high as 77 and 75 per cent (ΔT= 0) are obtained for 1.0 μm black chrome on copper and nickel plated steel, respectively. The lowest loss coefficients are about 3.8 W/m2°C for all black chrome/metal surfaces, with the highest being 8.4 W/m2°C for the black paint/metal sample. Also, a collector model is presented for
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