Fenestration and Energy Conservation

Abstract

A previous review of the literature on the psychological requirements for windows indicated the desirability of a view out, daylight, sunshine, and spaciousness as the primary benefits of windows to people in buildings. Although the desire for these window benefits may be, at times, incompatible with the need for energy conservation, recent computer calculations at the National Bureau of Standards (NBS) indicate the feasibility of window management as a means of energy conservation. Window management is defined as the use of thermal shutters on winter nights, ventian blinds on summer days, and/or daylight. These calculations, however, assume that the window system is used optimally, and do not examine actual window management practices. These practices were, however, examined in a study at NBS in which Venetian blind use was evaluated for six low-rise office buildings having two orientations. Blind usage patterns were examined by photographing the building facades before and after experimentally changing blind position in three seasons. Blind positioning did not change noticeably from day to day but that of south-facing windows was significantly different from that of north-facing windows. The feasibility of relying on window management by altering Venetian blind position is discussed.