Calculation of meteorological data for thermal modeling of energy consumption on buildings

Energy, which provides the continuity of life, has become an important sector in the world. Factors such as population growth and technological advances increase energy consumption. On the other hand, continuing dependence on fossil resources, rising energy prices, global warming and climate change, countries worry about meeting their energy needs. This necessitates effective use of energy. Nowadays, one of the development indicators of countries has been the efficient use of energy. For this reason, studies on energy efficiency are still in progress. It is one of the priorities of these studies to know in which area, how and where the consumed energy is used. Research shows that one third of the energy used is consumed in the buildings. Buildings are considered economically long-lived products. At the same time they form a never-ending and developing sector. Because of this significant energy consumption, the energy efficiency of the buildings is accelerated. It is necessary to reduce energy consumption by providing thermal comfort conditions in buildings. The energy consumption needs to be calculated correctly in the works to increase the energy efficiency. Architects and engineers have important responsibilities in this regard. Standards and regulations have been set up for accurate estimation of energy consumption in buildings throughout the world. These standards include the methods used to calculate the building's heating load demand value. Thus, the amount of energy used to heat the buildings is limited. The regulations also include methods for calculating energy saving requirements of existing buildings and for taking energy saving measures before the renewal project is implemented. Three different methods are used as the prediction method. These methods are monthly/seasonal statical analysis, hourly simple analysis methods and dynamic analysis methods. According to the monthly/seasonal statical analysis, the heating-cooling energy requirement is calculated by monthly/seasonal interval method, which is a static analysis method. The actual thermal performance of the building does not participate in the calculation, and the rate of error is high especially during mid-seasons. The hourly simple dynamic analysis method is the procedure used in Turkey's Building Energy Performance National Calculation Method. With the resistance-capacity model, it is able to reflect the building's hourly thermal behavior close to actual. It is possible to estimate the amount of net energy in mid-seasons and to define comfort conditions according to operating temperature. The solar heat gain, which affects the building energy loads, determines the performance of the solar control elements by taking account of the position of the sun in the year, daily and hourly. In the detailed dynamic simulation analysis method, in order to calculate the heating-cooling load of the building, the thermal conditions of the building, the energy amount consumed in the year is determined by performing a mathematical analysis on the efficiency. Heating, ventilation and air conditioning tools are also mathematically analyzed against these loads to calculate the amount of energy consumed during the year. Turkey also determines the rules for the thermal insulation in order to reduce the energy consumption in buildings "TS 825 Thermal Insulation Requirements in Buildings in Turkey" and EN ISO 13790 standard comprises predicting the energy consumption for heating and cooling the building "Energy performance of buildings – Calculation of energy use for space heating and cooling" was adopted by the relevant ministry. However, there are cases where a building is in compliance with regulations, but energy is ineffective in some cases. There are also insufficiencies in the regulations. Because they consist of expressions based on empirical formulas and are dynamically away from the energy performance of the building. Especially in the mid seasons, deviations are observed. For this reason, new methods are being studied to predict building energy performance. The meteorological data and internal heat gains are the basis of calculations of building energy performance. The fact that the data used reflects the actual is important for the predictions to give the accurate result. Climatic data are obtained by measurements made at measurement stations. However, there are difficulties in reaching this data (in terms of region and period). One of the internal heat gains of building energy performance calculations is solar heat gains. However, there are difficulties and inadequacies in reaching solar radiation data. Because there is no measuring station in every region. For this reason, it has become a necessity to obtain by calculating the solar irradiance coming the building. In this study, it is aimed to apply calculation method of the solar flux coming to vertical surface on formed thermal models. In this study, the current regulations in force in Turkey briefly described and compared. In order to calculate the energy performance of the buildings with dynamic analysis method, two different new methods which were developed previously were edited and the formulation was explained in detail in the context of the accepted assumptions. In the first method, the lumped approach is taken as two different control volumes in the envelope and the indoor. Firstly, differential equations systems were established based on the equation of energy conservation. Then the initial and boundary conditions are determined. By the solution of the differential equation system, equations giving the internal temperature and the envelop temperature of the building have been obtained depending on the time. Thus, if the outside temperature distribution is known, the temperatures of the internal and exterior walls of the inspected building are dynamic analysis calculated for the desired time steps. In the second method, a thermal model was formed based on the parabolic heat equation. After determining the boundary conditions for the building envelope, the system of differential equations is solved using the appropriate solution method. thereby, mathematical expressions that give the internal and exterior wall temperatures of the building have been obtained depending on the outdoor temperature and time of the building. In this study, the calculation method of solar flux that needs to be known for apply on thermal models is explained. For this, the basic and derived sun angles are explained, the solar time is defined and the calculation is explained. In addition, the attenuation of solar radiation through atmosphere is mentioned, and the equations about extraterrestrial radiation are given. Following these explanations, definitions of total, direct and diffuse radiation thats coming to the earth have been made. The equations of instantaneous and daily solar radiation coming to horizontal and inclined surfaces on the earth are explained by explaining. Thus, the instantaneous solar irradiance coming a geostationary building in any direction is calculated. For this, a system was created in Excel program. In this study, for the calculation of the building heating energy requirement is followed by a simple to complex method, which describes the thermal models formed. In these models resistance-capacity model is used by using the finite difference equations. A thermal model was developed for a sample room, which is assumed to have heat loss and gain only from exterior walls and windows. The outer wall and the windows were considered to be parallel connected plates and the one dimensional heat transfer equation was solved using the finite difference method. In order to compare, analytical solutions of steady state problems are included. In the beginning, only the outer wall and the compound parallel wall structure composed of windows are added to the models which are considered to be formed only from the outer wall. In addition, models have been developed by adding equal solar irradiance to the exterior walls and windows. The data obtained from the generated Excel program is used here, thereby, it is possible to calculate the outside wall temperature, the inside and outside surface temperatures of the wall for desired time steps. Finally, the solution is made according to the calculation method in TS EN ISO 13790 standard and the results are compared. In comparison, wall temperature, inner surface temperature of the outer wall and energy loss results were found to be less than five percent. It is proposed that the solutions found in the methods presented in the study can be taken as a reference in heat loss calculations in the buildings. In addition, it is suggested that a more flexible model can be developed based on the solution method presented here. The program, which is generated by the calculation of the instantaneous solar radiation coming the inclined plane in the study, can also be used in the design of other solar energy systems. Thus, it is suggested to use the results obtained by calculating the solar irradiance coming the surface for region where there is no measuring station or data access is difficult. Likewise, it has been proposed that the solution adapted to method of TS EN ISO 13790 standard for the variable outside temperature should be setted by determining the limits to be used and adding solar flux. Accurate calculation of energy consumption in the buildings ensures that energy losses are avoided, thus making significant progress in the area of energy efficiency. At the same time, a system will be established to determine the initial investment costs of the newly constructed buildings in the most appropriate way and to reduce the expenses in the utilization process, and it is possible to gain economic sense in this regard. In this way, both environmental and economic benefits are gained.