Zero energy building design for different types of climates

In recent years, due to increasing energy consumption and decreasing fosil fuel based energy resources, reducing energy consumption has become inevitable. Buildings consume 35% to 40% of the energy generated in the world to provide heating, ventilating, air conditioning and lighting. For this reason designing high efficiency buildings is essential to reduce the energy consumption in buildings. In order to reduce energy consumption the buildings' the mechanical systems should be selected from high efficiency mechanical systems. In many countries standards and regulations require the design of high efficiency buildings. One of the most important of these regulations is Energy Performance of Buildings Directive Recast (EPBD Recast) in the European Union. The main object of this regulation is to reduce energy consumption and greenhouse gas emissions in order to reduce their effect on global warming. The Nearly Zero Energy Buildings regulation applies to all EU countries as of 31 December 2020. Starting on the 1st of January 2021 all new buildings must be constructed as Nearly Zero Energy Building to meet the requierments of very high energy performance buildings. In this thesis, by taking the instructions in the regulations as a reference, the aim is to form solution packages for two sample buildings. Using one building example in a cold climate and one building example in a warm climate and then making passive designs and using active solutions in construction and mechanical systems in order to make traditional residence buildings Net Zero Energy Building or Nearly Zero Energy Building. Also, the instructions and examples in REHVA (Federation of European Heating, Ventilation and Air-Conditioning Associations) were taken into consideration. Another important point of this study is to emphasize the important of the climate conditions. The solution packages were formed by using optimum design solutions according to cold and warm climate conditions. In order to analyse the cold climate zone and design the building for these conditions, the pilot city selected was Berlin, Germany. For the pilot city in warm climate Izmir, Turkey was selected. The reason for solutions packages and precautions taken are specific to climate zones, it is shown by calculations and simulation results that design criteria cannot be suitable with the other climate conditions. Hence, this study emphasizes that the climate conditions have a major effect on the design conditions and to show the solution packages must be cost effective. In the first chapter, aim and scope of this study was given. Studies by orthers and their results were included in a literature review. These studies are of energy analysis for building in different climates, building envelopes in Turkey's climate zones. Methodology of the study was also introduced in the chapter. In the study, for Nearly Zero Building design, the annual primary energy consumption 60 kWh/m2 is a maximum limit reference and 0 kWh/m2 is taken as the annual primary energy consumption for Net Zero Energy Building design. In order to achieve these results, firstly the building envelope was modified by using passive solutions. In the second chapter, the common properties of the buildings in different climates were given in detail; number of people, maximum power densities of lights and electric equipment and other loads. These values are compatible with the ASHRAE standards. In the fourth chapter, firstly, a TS825 standard validated building was modelled and its heating and cooling energy demands were evaluated by using EnergyPlus. Calculations were made with weather data for Izmir and Berlin which can be considered as a sample location for cooling-weighted Mediterranean climate and for heating-weighted cold climate. Then the passive solutions options were evaluated one by one through building energy simulation software. The precautions were taken in the building envelope especially in external walls and windows which are the primary components for a building envelope. First, the construction materials in walls, ground and floor were determined according to the cold and warm climates. Second solution is the insulation thickness of the construction. For external walls, roof and ground the insulation thickness was studied parametrically up to 30 cm. The external wall insulation thicknesses were taken 8 cm for Izmir and 15 cm for Berlin in order to design cost effective building. By using insulation as mentioned before for the building in Izmir, the annual heating energy demand was reduced but annual cooling energy demand increased 6%. Also in Berlin, the annual heating energy demand was reduced substantially but, decrease in annual cooling energy demand increased approximately 17%. The analysis results show that any improvement on cooling energy demand in warm climate will have a substantial impact on total energy efficiency and any improvement on heating energy demand in cold climate will have a substantial impact on total energy efficiency. The window-wall ratio was determined by using the standards (TS825) and results of the analysis. In order to reduce the heating energy demand in Berlin and cooling energy demand in Izmir window-wall ratios are taken 12% for Berlin and 24% for Izmir. Following the window properties were determined for each climate zones by simulating different window type's data was selected from the EnergyPlus software library. Also, in Izmir, a film coated double pane window was used to decrease the effect of the sun's radiation. In Berlin triple pane window was used to benefit from the sun radiation. Window shading was used to reduce the cooling energy demand in summer or springs. To determine the optimum solution the shading with the same shape at different angles were analysed through EnergyPlus. For both buildings, 90 degrees shading was used. In Izmir, all windows have a shading. In Berlin all windows have a shading except north side. At this stage, optimum solutions were created according to the climate zone which building is affected. The simulation results and comparison studies were given in the related sections. During the analysis for passive solutions to observe the effects on annual energy consumption of the buildings, HVAC system of the building was deactivated. Thus, any changes in annual energy requirement of the buildings can be noticed easily and the importance of every parameter is shown by the results. The estimated initial annual primary energy consumptions were reduced substantially by passive design and active solutions. In the fifth chapter, optimum HVAC systems were selected and applied for each building. As HVAC systems VRF heat pump and fan coil system were applied to the buildings. In fan coil systems water cooled chiller systems and boilers were used for both HVAC system templates and data was selected from the EnergyPlus software library. In Berlin, under the influence of cold climate conditions, the energy consumption for heating is too high and to reduce this number a condensing boiler was used. In Berlin, by using VRF heat pump system, the annual primary energy consumption 136.17 kWh/m2 while the annual primary energy consumption is saving 22.4% by using fan coil system. In Izmir, by using a fan coil system, the annual primary energy consumption is 94,86 kWh/m2 while the annual primary energy consumption is saving 33,2% by using VRF heat pump system. The detailed comparison part was given in the sections of the fifth chapter. In the final stage, solar energy which is widely used as renewable energy, was used for both climate zones, electricity was generated to decrease the annual primary energy requirement. The solar radiation data and optimum tilt angles for both climate zones were evaluated by using PVsyst software. By considering these values, optimum places were selected on the roof to get the solar radiation with minimum loss and the maximum number of panels was calculated. By taking into considerations the determined results, some improvements were made to design a cost effective system. By generating energy as electricity from solar panels, Net Zero Energy Building or Nearly Zero Energy Building design was achieved in the study. The annual solar energy production for Izmir satisfies the annual energy requirement of the building because of the climate conditions in Berlin the annual solar energy production was not sufficient to generate the annual energy requirement. In order to make the building in Berlin as Nearly Zero Building, some improvements were made retrospectively. Improvements to the building envelope including adding gradual insulation thicknesses to the external wall, roof and ground. Finally, the aim of this study is achieved by the solution packages used. The annual primary energy consumption 0 kWh/m2 for Izmir and 59,57 kWh/m2 for Berlin by using solar energy. It's possible to improve this result by optimizing the using fan coil heat pump system for Berlin. Also using VRF heat recovery system for Izmir the annual energy requirement of the building can be reduced by providing cooling and heating as needed. Also, with the advance of technology better window type can be used for Berlin to gain more benefit from the solar radiation for heating in winter and to reduce the consumption for lighting. The high efficiency buildings are still too expensive and not cost affective but with the advance of technology the prices will drop and the high efficiency buildings numbers will increase. In this thesis study, three dimensional modelling of the building was generated in SkecthUp. For the numerical solution part to evaluate the annual primary energy consumption was made in EnergyPlus software which is preferred by engineers and architectures in building energy analysis. The OpenStudio program was used for construction details, building envelope material properties and HVAC systems basics. In addition PVsyst software was used to calculate energy produced for each climate zones. Meteonorm data was used as meteorological reference.