Some study results of natural illumination and lighting quantity earth´s surface around Ulaanbaatar

The article deals with some results of determining the natural illumination and lighting quantity of horizontal and differently oriented vertical Earth´s surface around Ulaanbaatar. We have studied the features and distribution of daily,monthly and annual course of direct (E_s), diffuse (E_D), total (E_Q) natural illumination and the values of lighting quantity (Σ_dE,Σ_mE - sum of daily and monthly lighting) earth´s surface in the city. Some problems natural illumination specifics of buildings in the conditions of Ulaanbaatar are examined. Results on calculation of light-climatic coefficient (m) and the standardized values of the natural illumination coefficient (e_n) for the business premises in Ulaanbaatar have been shown.For the first time there was composed the nomogram for calculating duration of natural illumination use around Ulaanbaatar. There was considered some issues of applying the nomogram which was disegned for different regions of national economy. We compared these results to the cities functioning at some latitude in Asia and in Europe.