Architectural integration of transpired solar thermal for space heating in domestic and nondomestic building envelopes

In response to climate change, energy poverty, and increasing prices of fossil fuel energy; building integrated renewable energy should find a quick and strong stream in design and construction fields. Solar thermal appears as a promising technology for domestic and nondomestic building envelopes, particularly for space heating which counts for 61% the total domestic energy consumption in countries with long cold seasons like UK. The integration of transpired solar collectors (TSC) technology however suffers lack of adoption in building envelopes despite its apparent technical competitiveness for using solar pre-heated external air for space heating since patented in the late-1980s. Architectural integration seems to play a major role in developing and encouraging the use of TSC in buildings. This paper therefore investigates the innovative possibilities of improving the architectural integration of TSC into building envelopes at both multi-functional and aesthetic levels. An international web-based survey was distributed to architects, engineers, and other academic and professionals in design and construction fields with intensive focus on countries with long heating seasons and potential integrations of TSC such as Canada, USA, and UK and mainland Europe. The responses of 1,295 participants, the largest pool ever for previous comparative studies in this field, were analysed quantitatively and qualitatively. Unlike previous studies the outcomes were statistically examined using Pearson’s Chi-square and Spearman’s correlation Coefficient tests. Although respondents only had a moderate awareness of the TSC technology they were very interested in integrating solar energy into the built environment. Seven selective integration images of TSC and photovoltaic (PV), from existing projects in Canada, USA and Europe were rated by respondents in terms of multifunctional and aesthetic roles of integration. The barriers and limitations along with preferable integration schemes were investigated and discussed. Integration parameters such as function, type, and position of TSC which were found to be the most favoured by the participants were identified. The survey results provide valuable contributing information of architecturally integrating transpired solar thermal in the built environment. This contribution is necessary for researchers and professionals in design and construction fields.