Performance and Reliability of Insulated Glass Collector Prototypes
Abstract
Insulated glass collectors represent a novel design intended for improved building integration, combining a multiple window glazing with a flat plate collector. Gas-filled gaps and low-emittance glass coatings can provide for a high performance, comparable to that of commercially available flat plate products by reducing the overall thickness from 90-100 mm to 50 mm. The paper presents the results of our investigations on optimized triple-glazed, argon-filled prototypes. Aim of the work is to compare different absorber technologies and integration solutions and to identify the most suitable design with regards to aesthetical appearance and long-term reliability. Efficiency measurements according to EN ISO 9806 confirm the findings of previous investigations: zero-loss efficiency η0 between 0.74 and 0.79 as well as an effective heat loss coefficient a40 between 4.2 and 4.5 W/m²K are reported, depending on the specific design considered. Indoor and outdoor reliability tests show promising results: no significant decrease of gas concentration has been detected in most cases and no degradation of the collector components, even after long-term exposure. Due to the gas-tightness of the unit, outgassing has been identified as a critical aspect to be taken into special consideration in the collector design and in the choice of components and materials.
Keywords
Flat plate collector, Insulated glass, Building integration.