Predicted and in situ performance of a solar air collector incorporating a translucent granular aerogel cover

Abstract

There is an opportunity to improve the efficiency of flat plate solar air collectors by replacing their conventional glass covers with lightweight polycarbonate panels filled with high performance aerogel insulation. The in situ performance of a 5.4m 2 solar air collector containing granular aerogel is simulated and tested. The collector is incorporated into the external insulation of a mechanically ventilated end terrace house, recently refurbished in London, UK. During the 7 day test period, peak outlet temperatures up to 45°C are observed. Resultant supply and internal air temperatures peak at 25 30°C and 21 22°C respectively. Peak efficiencies of 22 36% are calculated based on the proposed design across a range of cover types. Measured outlet temperatures are validated to within 5% of their predicted values. Estimated outputs range from 118 166 kWh/m 2 /year for collectors with different thickness granular aerogel covers, compared to 110 kWh/m 2 /year for a single glazed collector, 140 kWh/m 2 /year for a double glazed collector and 202 kWh/m 2 /year for a collector incorporating high performance monolithic aerogel. Payback periods of 9 16 years are calculated across all cover types. An efficiency up to 60% and a payback period as low as 4.5 years is possible with an optimised collector incorporating a 10mm thick granular aerogel cover.

Domestic UK retrofit challenge: Barriers, incentives and current performance leading into the Green Deal

“…This study forms part of a wider research project focused on product development and life cycle assessment of novel retrofit technologies incorporating silica aerogel insulation (see Dowson et al 2011aDowson et al , 2011bDowson et al and 2012.…”

Modelling and simulation of Building-Integrated solar thermal systems: Behaviour of the system

“…Dowson et al [14] presented measurement results of a polymer air collector with aerogel. Based on the measurements, the collector was modelled and the annual gain was calculated as well as a payback time.…”

Elliot and Symmetric Elliot Extreme Learning Machines for Gaussian Noisy Industrial Thermal Modelling

“…Notton et al [17] develop a mix of finite differences and electrical analogy models to compute the outlet temperature of a solar thermal collector integrated in a building. Dowson et al [18] applied a numerical modelling technique to an aerogel covered, integrated, solar air collector for computing outlet temperatures.…”