Abstract

Window openings represent disproportionately large amounts of energy loss, due to low thermal resistance of glass. Implementing current window improvement methods would entail significant changes to the existing exterior wall structure. One method that can overcome this limitation is to use bi-folding window doors that incorporate thermal insulation. This paper presents the feasibility of using insulated bi-folding window doors in improving energy efficiency of existing buildings. Thermal pictures of prototype insulated bi-folding doors were acquired and analyzed, and a cost-benefit analysis was performed on a case study building. The results of analysis indicated that insulated bi-folding doors could improve energy efficiency of the case study building by nearly 20% while the up-front investment costs would be paid back in less than three years.