The impact of windows on visual perception in office spaces in hot and humid tropical climates

Abstract Daylighting is beneficial for buildings and their occupants; however, in tropical climates, daylight is often excessive, and it is a source of glare and cause of frequent use of artificial lighting. With the objective of analysing the influence of windows and daylighting on visual perception in workplaces, this study was conducted in two office buildings in the city of João Pessoa, state of Paraíba, Brazil: illuminance at desk level was recorded at 219 workstations, simultaneously to a questionnaire application. The wide range of illuminance indices (from 6,77 to 2620,4 lux) demonstrates the difficulty of achieving uniform conditions that are in conformity with the standards, with recurrent indices around 750 lux leading to 30,15% of occupants’ dissatisfaction. Internal shading elements predominated in the ‘closed’ position and a low percentage of activation by users (22,94%), since the frequency of activation was related to device proximity. The results suggest that windows may be related with high dissatisfaction with daylight when they allow excessive incidence of sunlight, especially when associated with east-facing facades with no external solar protection.

摘要 自然采光（Daylighting）对建筑及其使用者均具有积极意义，但在热带气候区域，自然光往往过量，不仅会引发眩光问题，还会导致人工照明的频繁启用。本研究以分析办公场所窗户与自然采光对视觉感知的影响为目标，在巴西帕拉伊巴州若昂佩索阿市的两栋办公楼中开展：在219个工位处记录桌面照度，并同步开展问卷调查。本次研究记录的照度指标范围跨度极大（6.77至2620.4勒克斯），这说明要达成符合相关标准的均匀照度环境颇具难度；当照度指标频繁维持在750勒克斯左右时，会导致30.15%的使用者产生不满情绪。内部遮阳设施大多处于“关闭”状态，使用者的启用率仅为22.94%，这是因为遮阳设施的启用频率与使用者的可及性密切相关。研究结果表明，当窗户允许过量太阳光入射时，尤其是搭配无外部遮阳的东向立面时，可能会导致使用者对自然采光产生较高的不满情绪。