Market-Oriented Cost-Effectiveness and Energy Analysis of Windows in Portugal

Glazed systems in buildings can account for a significant part of overall energy consumption. The unfavorable relationship between energy savings and the increased cost of energy-efficient windows is often the main drawback cited by customers to justify its non-acquisition. of glazed windows. This study addresses the relationship between the investment costs in windows and their energy performance and associated costs. Seventeen window manufacturers were contacted. This survey studied the state-of-the-art and the most-used windows in terms of energy efficiency and cost. Calumen and Guardian Configurator software were used to perform this assessment. Additionally, SEnergEd software was used to simulate the energy performance and compute the equivalent annual cost for the entire life cycle of buildings. Besides the economic benefits, the impact of the energy performance of the windows on the energy performance of the building was also studied. In terms of energy, the most efficient glazing system was two windows per span, resulting in a combined solar factor of 0.43 and a 0.55 W/(m²·K) heat-transfer coefficient. On the other hand, one window per span, with a solar factor of 0.79 and a 3.05 W/(m² K) heat-transfer coefficient is the most cost-efficient to be used in Portugal.