One of the tenets of urban sustainability is that more compact urban forms that are more densely occupied are more efficient in their overall use of space and of energy. In many designs this has been translates into high-rise buildings with a focus on energy management at their outer envelopes. However, pursuing this building focused approach alone means that buildings are treated as standalone entities with minimal consideration to their impact on the surrounding urban landscape and vice versa. Where urban density is high, individual buildings interact with each other, reducing access to sunshine and daylight, obstructing airflow and raising outdoor air temperature. If/when each building pursues its own sustainability agenda without regard to its urban context, the result will diminish the natural energy resources available to nearby buildings and worsen the outdoor environment generally. This paper examines some of these urban impacts using examples from the City of London where rapid transformation is taking place as very tall buildings with exceptional energy credentials are being inserted into a low-rise city without a plan for the overall impact of urban form. The focus of the paper is on access to sunshine and wind and the wider implications of sustainable strategies that that focuses on individual buildings to the exclusion of the surrounding urban landscape. The work highlights the need for a framework that accounts for the synergistic outcomes that result from the mutual interactions of buildings in urban spaces.
Building performance evaluation is generally carried out through a non-automated process, where computational models are iteratively built and simulated, and their energy demand is calculated. This study presents a computational tool that automates the generation of optimal building designs in respect of their Life Cycle Carbon Footprint (LCCF) and Life Cycle Costs (LCC). This is achieved by an integration of three computational concepts: (a) A designated space-allocation generative-design application, (b) Using building geometry as a parameter in NSGA-II optimization and (c) Life Cycle performance (embodied carbon and operational carbon, through the use of thermal simulations for LCCF and LCC calculation). Examining the generation of a two-storey terrace house building, located in London, UK, the study shows that a set of building parameters combinations that resulted with a pareto front of near-optimal buildings, in terms of LCCF and LCC, could be identified by using the tool. The study shows that 80% of the optimal building’s LCCF are related to the building operational stage (σ = 2), while 77% of the building’s LCC is related to the initial capital investment (σ = 2). Analysis further suggests that space heating is the largest contributor to the building’s emissions, while it has a relatively low impact on costs. Examining the optimal building in terms compliance requirements (the building with the best operational performance), the study demonstrated how this building performs poorly in terms of Life Cycle performance. The paper further presents an analysis of various life-cycle aspects, for example, a year-by-year performance breakdown, and an investigation into operational and embodied carbon emissions.
Resource accounting is widely practiced to identify opportunities for improving the sustainability of industrial systems. This paper presents a conceptual method for resource accounting in factories that is based on the fundamentals of thermodynamics. The approach uses exergy analysis and treats the factory as an integrated energy system comprising a building, its technical building services and manufacturing processes. The method is illustrated with a case study of an automotive cylinder head manufacturing line in which the resource efficiency of this part of the factory is analysed for different energy system options relating to heating ventilation and air conditioning. Firstly, the baseline is compared with the use of a solar photovoltaic array to generate electricity, and then a heat recovery unit is considered. Finally, both of these options are used together, and here it was found that the non-renewable exergy supply and exergy destruction are reduced by 51.6% and 49.2% respectively. Also, it was found that a conventional energy analysis would overestimate the resource savings from reducing the hot water supplied to the heating system, since energy analysis cannot account for energy quality. Since exergy analysis accounts for both energy quality and quantity it produces a different result. The scientific value of this paper is that it presents an exergybased approach for factory resource accounting, which is illustrated through application to a real factory. The exergy-based approach is shown to be a valuable complement to energy analysis, which could lead to a more resource efficient system design than one based on energy analysis alone.
Abstract:The aim of this research is to assess the indoor thermal performance of rural dwellings in the Ecuadorian highlands through both experimental and numerical analysis. A three-step methodology was applied to conduct the research: (a) field data collection, (b) building thermal model development and calibration, and (c) comparison analysis and assessment of traditional improvement strategies. Qualitative and quantitative data were collected from two representative rural dwellings under typical usage conditions. The first is a traditional construction, medium-exposed thermal mass dwelling (Case A). The second is a local common, uninsulated, lightweight construction (Case B). The thermal model was calibrated by comparing hourly temperature values of the observed and the predicted indoor air temperature. A high correlation level (R 2 ) was achieved between the observed and predicted data; 0.89 in Case A and 0.94 in Case B. The results show that the roof, floor, and the airtightness are the critical building parameters affecting the indoor thermal environment. Likewise, the indoor air temperature is increased up to 4 • C through the implementation of traditional strategies. However, despite the rise in indoor air temperature, acceptable thermal comfort ranges were only reached for 25% of the total hours.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.