RESEARCH OF TIME OF CRITICAL ILLUMINATION TO ASSESS THE DURATION OF DAYTIME ILLUMINATION

Abstract

Natural lighting of buildings has an important morphofunctional value, since the human body is formed in the natural environment. In modern conditions, additional lighting with artificial light sources is used with a lack of natural lighting, this leads to energy costs. The duration of the use of day light depends on many factors, including the light climate of the region. In this paper, authors propose an approach to the preliminary assessment of the time of use of day lighting, taking into account differences in the light climate. Calculations of day illumination on an open horizontal surface are carried out for three cities of the Russian Federation (Sochi, Moscow, St. Petersburg) on the basis of actinometric reference data using the light equivalent of solar radiation for all months of the year by daylight hours. The calculation uses the total solar radiation for clear and cloudy skies with hourly accounting for the probability of sunshine. The value of critical outdoor natural illumination is selected from the specialized literature. Based on the calculated data obtained on the distribution of illumination on a horizontal surface and the value of critical illumination, a table of the end time in the morning and the begin time of intermediate light in the evening for each city and month of the year under consideration is compiled. Therefore, in Sochi, the estimated time of using day light is 4 hours longer than in Moscow, and 7 hours longer than in St. Petersburg. This approach can be used for a preliminary assessment of the duration of the use of day light. Further works of the authors will be devoted to clarifying this approach.