A Pareto-based multi-objective optimization algorithm to design energy-efficient shading devices

In this paper we address the problem of designing new energy-efficient static daylight devices that will surround the external windows of a residential building in Madrid. Shading devices can in fact largely influence solar gains in a building and improve thermal and lighting comforts by selectively intercepting the solar radiation and by reducing the undesirable glare. A proper shading device can therefore significantly increase the thermal performance of a building by reducing its energy demand in different climate conditions. In order to identify the set of optimal shading devices that allow a low energy consumption of the dwelling while maintaining high levels of thermal and lighting comfort for the inhabitants we derive a multi-objective optimization methodology based on Harmony Search and Pareto front approaches. The results show that the multi-objective approach here proposed is an effective procedure in designing energy efficient shading devices when a large set of conflicting objectives characterizes the performance of the proposed solutions. (C) 2016 Elsevier Ltd. All rights reserved

Life cycle assessment of nano-sized titanium dioxide coating on residential windows

The use of nano-sized titanium dioxide (TiO2) as coating in buildings has received considerable interests in recent years due to its excellent ability to purify the environment by capturing some of the pollutants in the air and by using its inherent photocatalytic properties to its advantage. This study employs Life Cycle Assessment (LCA) to evaluate the use of nano-sized titanium dioxide coating on residential window glass. To achieve this objective, this study compiled a Life-Cycle Inventory (LCI) for quantifying the energy and emissions of the coating during the manufacturing process and in-service. The Building for Environmental and Economic Sustainability (BEES) model was employed to develop the life cycle inventory of titanium dioxide coating on windows. The LCA framework used in this study was based on a life cycle methodology that follows the International Organization for Standardization (ISO) 14040 standard for life cycle assessment and the ASTM standard for Multi-attribute Decision Analysis. Based on the analysis conducted, it may be concluded that the use of TiO2 coating on window panes carries a positive effect on acidification potential, eutrophication potential, criteria air pollutants and smog formation potential, while it increases environmental loads in global warming, fossil fuel depletion, water intake, human health, and ecological toxicity. However, the overall normalized performance on the environment and air purification is positive. © 2012 Elsevier Ltd. All rights reserved

The effect of shading design and materials on building energy demand

Building sector in most countries around the world requires large amounts of heating and cooling energy. Indeed, building cooling loads due to solar gains are responsible for approximately half of global cooling load. In addition, windows are considered as one of the important sources of energy loss in buildings. In order to minimize this loss, shading devices can be installed in the exterior part of the window to reduce solar heat. The objective of this study is to investigate the simultaneous effect of glazing, shading materials, and configuration of shading devices on total building energy consumption in different climate regions in the United States. To achieve this objective, a typical residential building was selected to assess the effect of the aforementioned parameters on total energy consumption in five main climate regions. A series of simulations were conducted using EnergyPlus simulation program to quantify energy consumption in each scenario and determine the most energy efficient glazing and shading materials as well as configuration of the shading device. Different types of window glazing (including clear, Low-Iron, Ref-B tint, Low-E clear and Low-E tint with 6 mm thickness) as well as different materials for shading devices (including PVC, aluminum and wood) were considered in this study. Moreover, the effect of five different shading device configurations, including horizontal and oriented overhang, vertical fin and combination of them were investigated. Results showed installing vertical fins and horizontal overhang shading devices in buildings located in Miami and Atlanta do not have a significant effect on annual energy consumption. However, combining these two overhang shading configurations will reduce energy consumption. In addition to shading configurations, it was found that Ref-B tint glazing material along with wood shading material reduced annual energy consumption by approximately 11.6% in Miami. However in Atlanta, total energy consumption was reduced by approximately 7% in the case of using Low-E tint glazing material along with wood shading material. No significant decrease in energy consumption was observed in cold climates.Non UBCUnreviewedFacultyOthe

Integrated life cycle energy and greenhouse gas analysis of exterior wall systems for residential buildings

This paper investigates the breakdown of primary energy use and greenhouse gas (GHG) emissions of two common types of exterior walls in the U.K.: insulated concrete form (ICF) and cavity walls. A comprehensive assessment was conducted to evaluate the environmental performance of each exterior wall system over 50 years of service life in Edinburgh and Bristol. The results indicate that for both wall systems, use phase is the major contributor to the overall environmental impacts, mainly due to associated electricity consumption. For the ICF wall system in Edinburgh, 91% of GHG emissions were attributed to the use phase, with 7.8% in the pre-use and 1.2% in end-of-life phases. For the same system in Bristol, emissions were 89%, 9% and 2%, respectively. A similar trend was observed for cavity wall systems in both locations. It was concluded that in each scenario, the ICF wall system performed better when compared to the cavity wall system. The results of the sensitivity analysis clearly show that the uncertainties relevant to the change of the thickness of the wall are quite tolerable: variable up to 5%, as far as energy and greenhouse emissions are concerned