Light in research
Visual comfort study in classrooms
by Anne Leeuw and Alois Knol Daylight is important for schools regarding energy usage and the health of teachers and students. The ‘Programma van eisen voor Frisse scholen’ (requirements for healthy schools) sets a number of requirements for the indoor environment. For the ‘Prins Florisschool’, an elementary school in Papendrecht, the current daylight situation has been studied and tested with these requirements. For this research measurements, simulations and questionnaires have been used.
Table 1. Requirements base upon ‘Programma van eisen voor Frisse scholen’
Requirements In our research we investigated certain requirements based upon the ‘Programma van eisen voor Frisse scholen’. We measured the illuminance levels and the daylight factor using a lux meter. The daylight factor is the ratio between the illumination of the sky (free field) and the working area. The evenness index (g) is the ratio between the minimal illuminance of the working are (Emin[lux]) and the mean illuminance (Egem[lux]). In addition to the ‘Programma van eisen voor Frisse scholen’ the DGP (Daylight Glare Probability) and the contrast have been added to the requirements. The human line of sight is approximately 180 degrees. However, the quality is not spread evenly over this field. This means that disturbing visuals are not always perceived the same. To determine if light is disturbing the aspect of contrast is analysed. The areas that can be analysed are the ergorama and 32
Figure 1. Human field of sight (Illuminating Engineering Society of North America, 1984)