Determination of Shading Reduction Factors When Shading by Rows of Trees

In temperate climates, where buildings need to be heated in winter and cooled in summer, trees provide good natural sun protection for buildings. Most tree species shed their leaves in winter. This allows the sun's rays to penetrate into the rooms and provide passive heating. However, in the summer, dense foliage blocks solar energy and reduces building cooling costs. When certifying buildings for energy, the problem arises of taking into account the influence of external shading on energy consumption for heating and cooling of buildings. To do this, it is necessary to know the value of the shading reduction factor, which is the ratio of solar radiation that arrived on the irradiated surface, shaded by sun protection, to solar radiation on this surface without shading. This factor is different during heating and cooling periods. The article presents a method for determining the shading factors of different types of trees that are planted in front of the facade of the house in the form of a row parallel to the facade. The transparency of a row of trees is modeled depending on the vertical angle of shading, the horizontal angle between the solar plane and the facade, and the density of the tree crown. For 5 architectural and construction climatic regions of Ukraine, the reduction coefficients of shading by 4 types of trees during periods of heating and cooling of buildings were calculated.