ENERGY AND ENVIRONMENTAL LIFE-CYCLE ANALYSIS OF ADVANCED WINDOWS

The environmental consequences of options for the manufacture, applica tion, disposal, reuse and recycling, applicable to the Full range of c urrently conceived advanced window systems, are discussed. Advanced wi ndow systems may incorporate, singly and in various combinations: evac uated contiguously-sealed glazing, electrochromics, thermochromics, ph otochromics, aerogels, xerogels, inert gas filled double glazings, low infra-red emittance coatings, diffractive daylight deflectors, hologr aphic daylight deflectors refractive daylight deflectors, toughened gl ass. The primary impetus for the development of such systems is that t heir use enables buildings to incur minimal energy use by reducing win dow heat losses and/or the displacement of electric lighting by enhanc ed daylighting The energy savings associated with advanced glazings di splace the combustion oi fossil fuels directly and indirectly; environ mental benefits thus ensue. However these benefits map be offset by th e impact of energy embodied from manufacture and the negative impacts of the extraction and disposal of constituent materials. Over their to tal life-cycle the environmental impact for advanced glazing systems a nd their associated means of manufacture, system fabrication and the t enable reuse, recycling and disposal options are unknown. The usefulne ss of life cycle analyses during the research and development stage is discussed.