Emergy-based sustainability assessment of different energy options for green buildings

It is necessary to minimize the environmental impact and utilize natural resources in a sustainable and efficient manner in the early design stage of developing an environmentally-conscious design for a heating, ventilating and air-conditioning system. Energy supply options play a significant role in the total environmental load of heating, ventilating and air-conditioning systems. To assess the environmental impact of different energy options, a new method based on Emergy Analysis is proposed. Emergy Accounting, was first developed and widely used in the area of ecological engineering, but this is the first time it has been used in building service engineering. The environmental impacts due to the energy options are divided into four categories under the Emergy Framework: the depletion of natural resources, the greenhouse effect (carbon dioxide equivalents), the chemical rain effect (sulfur dioxide equivalents), and anthropogenic heat release. The depletion of non-renewable natural resources is indicated by the Environmental Load Ratio, and the environmental carrying capacity is developed to represent the environmental service to dilute the pollutants and anthropogenic heat released. This Emergy evaluation method provides a new way to integrate different environmental impacts under the same framework and thus facilitates better system choices. A case study of six different kinds of energy options consisting of renewable and non-renewable energy was performed by using Emergy Theory, and thus their relative environmental impacts were compared. The results show that the method of electricity generation in energy sources, especially for electricity-powered systems, is the most important factor to determine their overall environmental performance. The direct-fired lithium-bromide absorption type consumes more non-renewable energy, and contributes more to the urban heat island effect compared with other options having the same electricity supply. Using Emergy Analysis, designers and clients can make better-informed, environmentally-conscious selections of heating, ventilating and air-conditioning systems.

[1]  Simone Bastianoni,et al.  Specific emergy of cement and concrete: An energy-based appraisal of building materials and their transport , 2008 .

[2]  Refrigerating.  ASHRAE handbook of fundamentals , 1967 .

[3]  Bhavik R Bakshi,et al.  Expanding exergy analysis to account for ecosystem products and services. , 2004, Environmental science & technology.

[4]  Joseph H. M. Tah,et al.  Mathematical modelling of embodied energy, greenhouse gases, waste, time–cost parameters of building projects: A review , 2013 .

[5]  Robert Ries,et al.  Comparison of energy-based indicators used in life cycle assessment tools for buildings , 2014 .

[6]  Zhang Peng,et al.  Generation of ambient temperature bin data of 26 cities in China , 2009 .

[7]  Luisa F. Cabeza,et al.  Life cycle assessment (LCA) and life cycle energy analysis (LCEA) of buildings and the building sector: A review , 2014 .

[8]  D. Sailor.  A review of methods for estimating anthropogenic heat and moisture emissions in the urban environment , 2011 .

[9]  Dezhi Li,et al.  An emergy analysis-based methodology for eco-efficiency evaluation of building manufacturing , 2011 .

[10]  Zhaoxia Wang,et al.  Analysis of energy efficiency retrofit schemes for heating, ventilating and air-conditioning systems in existing office buildings based on the modified bin method , 2014 .

[11]  F. Meillaud,et al.  Evaluation of a building using the emergy method , 2005 .

[12]  Baizhan Li,et al.  Urbanisation and its impact on building energy consumption and efficiency in China , 2009 .

[13]  Sergio Ulgiati,et al.  Emergy evaluations and environmental loading of electricity production systems , 2002 .

[14]  J. C. Lam,et al.  Future trends of building heating and cooling loads and energy consumption in different climates , 2011 .

[15]  Inge Blom,et al.  LCA-based environmental assessment of the use and maintenance of heating and ventilation systems in Dutch dwellings , 2010 .

[16]  Sergio Ulgiati,et al.  Quantifying the environmental support for dilution and abatement of process emissions The case of electricity production , 2002 .

[17]  Baizhan Li,et al.  A generic model of Exergy Assessment for the Environmental Impact of Building Lifecycle , 2010 .

[18]  Radu Zmeureanu,et al.  Comparison of environmental impacts of two residential heating systems , 2008 .

[19]  Luis Pérez-Lombard,et al.  A review on buildings energy consumption information , 2008 .

[20]  Varun,et al.  Life cycle assessment of buildings: A review , 2011 .

[21]  Howard T. Odum,et al.  Concepts and methods of ecological engineering , 2003 .

[22]  Riccardo Maria Pulselli,et al.  Energy and emergy based cost–benefit evaluation of building envelopes relative to geographical location and climate , 2009 .

[23]  Inge Blom,et al.  Environmental impact of building-related and user-related energy consumption in dwellings , 2011 .

[24]  Zhang Yufeng,et al.  Assessment for central heating systems with different heat sources: A case study , 2012 .