استفاده از تجزیه و تحلیل حساسیت در طراحی ساختمان پایدار

Building performance can be expressed by different indicators such as primary energy use, environmental load and/or the indoor environmental quality and a building performance simulation can provide the decision maker with a quantitative measure of the extent to which an integrated design solution satisfies the design objectives and criteria. In the design of sustainable buildings, it is beneficial to identify the most important design parameters in order to more efficiently develop alternative design solutions or reach optimized design solutions. Sensitivity analyses make it possible to identify the most important parameters in relation to building performance and to focus design and optimization of sustainable buildings on these fewer, but most important parameters. The sensitivity analyses will typically be performed at a reasonably early stage of the building design process, where it is still possible to influence the most important design parameters. A methodology of sensitivity analysis is presented and an application example is given for design of an office building in Denmark.

Energy use for room heating, cooling and ventilation accounts for more than one-third of the total, primary energy demand in the industrialized countries, and is in this way a major polluter of the environment. To successfully achieve the targets set out in the Kyoto protocol it is necessary to identify innovative energy technologies and solutions for the medium and long term which facilitates the implementation and integration of low carbon technologies, such as renewable energy devices, within the built environment. Building performance can be expressed by different indicators as primary energy use, environmental load and/or the indoor environmental quality and a building performance simulation can provide the decision maker with a quantitative measure of the extent to which an integrated design solution satisfies the design objectives and criteria. In Denmark new requirements for primary energy consumption in new buildings, including heating, cooling, domestic hot water, ventilation and lighting (not included for residential buildings), entered into force in April 2006. The total primary energy use has to be calculated by a newly developed software program BE06 [11], which applies a simplified method for calculation of energy use based on mean monthly average values for climate data, heat loads and occupation schedules. The primary energy consumption for all buildings (except residences) must not exceed: View the MathML source(95+2200A)kWh/m2year Turn MathJax on where A is the heated floor area of the building. In order to reach a label as a low energy building the primary energy consumption must not exceed: View the MathML sourceClass1:(35+1100A)kWh/m2yearClass2:(50+1600A)kWh/m2year Turn MathJax on In the calculation of the primary energy use, energy use for heating is multiplied by a factor of 1.0 while electricity use is multiplied by a factor of 2.5. Besides requirements on the energy consumption the building regulations also put requirements on air tightness (1.5 l/s m2 floor area at a pressure difference of 50 Pa) and heat loss (6 W/m2 envelope (except windows and doors) at a temperature difference of 32 K). The latter means that the average U-value for the building envelope must not exceed 0.19 W/m2 K. The new requirements implied a reduction of 25–30% from the previous requirements and the plans for the future development include similar reductions in 2010 to a maximum level similar to Class 2 and in 2015 to a maximum level similar to Class 1. Achievement of reductions of the energy use in new buildings to low energy class 1 or 2 will require development of more holistic building concepts, where an integrated design approach is needed to ensure a system optimization and to enable the designer(s) to control the many design parameters that must be considered and integrated. Therefore, in the design of integrated building concepts it will be very beneficial to be able to identify the most important design parameters in order to more efficiently develop alternative design proposals and/or reach optimized design solutions. This can be achieved by applying sensitivity analysis early in the design process. A sensitivity analysis makes it possible to identify the most important design parameters in relation to building performance and to focus design and optimization of sustainable buildings on these fewer, but most important parameters. A sensitivity analysis will typically be performed at a reasonably early stage of the building design process, where it is still possible to influence the selection of important parameters. The objective of the present paper is to present a methodology of sensitivity analysis and by an application example of the design of an office building in Denmark to demonstrate the benefits achieved in a design process and an example of what design parameters contribute significantly to sustainable building energy performance in office buildings in Denmark.