Modelling of Solar Irradiance Incident on Building Envelopes in Polish Climatic Conditions: The Impact on Energy Performance Indicators of Residential Buildings

In this study, we use the data of Polish typical meteorological years and 15 transposition models to obtain global solar irradiance on sloped surfaces to calculate solar irradiance on external building partitions, solar gains, heating demands, and primary nonrenewable energy for heating and domestic hot water (EPH+W) of two typical Polish residential buildings, each for two variants in five locations. In relation to TMYs, annual solar gains were lower by -31% and -36% on average in a single and multifamily building, respectively, and the annual heating demands increased by 9% and 16%, respectively. Consequently, averaged EPH+W in relation to TMYs rose by 1.4 kWh/m(2) and 4.5 kWh/m(2), respectively. The mean differences between TMYs and the new method from the recently published EN-ISO 52010 standard for test Building 1 were 1.6 and 1.2 kWh/m(2), for Variants 1 and 2, respectively. Similarly, for test Building 2, the mean differences were 5.1 kWh/m(2) and 3.9 kWh/m(2), respectively. This means that the simulation model that is chosen has a visible impact on a building's energy performance indicators and its rating without any changes in the physical structure and use of the building.