Energy and environmental performance optimization of a wooden window: A holistic approach

• Windows analysed assessing thermal, optical, acoustic and LCA performance.
• The use phase reveals the highest energy-environmental impacts for windows.
• Optimized windows are proposed adopting a holistic approach.
• Windows equipped with solar control films shows the best global performance.

The paper reports the results of an extended investigation performed on a sample of wooden window selected as case study. A holistic approach was chosen to define all the main parameters characterizing the sample from the thermal, acoustic, mechanical, optical and environmental points of view. After an accurate state of the art survey, experimental measurements and numerical simulations were performed in order to evaluate the following parameters: thermal transmittance, airborne sound insulation, solar, light and UV transmittance, air permeability, water tightness, resistance to wind load. A LCA study allowed to correlate the energy and environmental impacts. By means of a comprehensive results analysis, a standard configuration of the window was defined (Scenario 0); two optimized scenarios were then selected, one including a solar control film in the glazing (Scenario 1) and another with a warm edge spacer replacing a common aluminium spacer (Scenario 2). A complete energy and environmental analysis was performed for all scenarios achieving a holistic evaluation of the benefits. Results show that in temperate climates the improvement of the window thermal characteristics, obtained through a proper control of solar radiation, is the most relevant criterion to optimize the overall energy and environmental performance of the window.