scholarly journals An assessment of the impact of selected construction materials on the life cycle energy performance and thermal comfort in buildings

2021 ◽  
Author(s):  
◽  
Rajesh Haripersad

South Africa is a developing country with various construction projects that are being undertaken both by government and the private sector. The requirements for the construction of energy-efficient buildings as well as the selection methods for providing construction materials have hence become important. Energy efficiency improvements needs to be implemented in the construction of these buildings in order to decrease energy usage and costs and provide more comfortable conditions for its occupants. Previous studies revealed that most of the focus for improving energy efficiency in buildings has been on their operational emissions. It is estimated that about 30% of all energy consumed throughout the lifetime of a building is utilized as embodied energy (this percentage varies based on factors such as age of building, climate and materials). In the past this percentage was much lower, but with increased emphasis placed on reducing operational emissions (such as energy efficiency improvements in heating and cooling systems), the embodied energy contribution has become more significant. Hence, it is important to employ a life-cycle carbon framework in analysing the carbon emissions in buildings. The study aims to augment energy efficiency initiatives by showcasing energy reduction strategies for buildings. The study assessed the thermal performance of selected construction materials by analysing different buildings using energy modelling program, EnergyPlus and TRNSYS. The parametric study was set in the central plateau region of South Africa and was performed to determine appropriate energy efficiency improvements that can be implemented for maximum savings. A life cycle cost analysis was performed on the selected improvements. The models created are representative of the actual buildings when simulated data is compared to recorded data from these buildings. Results showed a significant variation in energy and construction costs with varying construction materials over the buildings’ life cycle. Findings suggest that there is a significant reduction in energy usage when simple efficiency measures are implemented. The study recommends the use of different energy efficient building materials and the implementation of passive interventions in the constructing of buildings; the thermal performance of a building be optimized to ensure thermal comfort and the developed model be adopted for use in the engineering and construction industry for the reduction of energy consumption.

2019 ◽  
Vol 111 ◽  
pp. 03028
Author(s):  
Nazanin Moazzen ◽  
Mustafa Erkan Karagüler ◽  
Touraj Ashrafian

Energy efficiency of existing buildings is a concept to manage and restrain the growth in energy consumption and one of the crucial issues due to the magnitude of the sector. Educational buildings are in charge of about 15% of the total energy consumption of the non-residential building sector. However, not only operational but also embodied energy of a building should be reduced to get the overall benefits of energy efficiency, where, using energy efficient architectural measures and low emitting materials during every retrofit action can be a logical step. The majority of buildings in Turkey and EU was built earlier than the development of the energy efficiency in the construction sector, hence, without energy retrofit, consume an enormous amount of energy that can be averted significantly by the implementation of some even not advanced retrofit measures. Furthermore, demolishing of a building to construct a new one is not a rational approach concerning cost, time and environmental pollution. The study has been focused on the impact assessment of the various architectural scenarios of energy efficiency upgrading on the Life Cycle Energy Consumption (LCEC) and Life Cycle CO2 (LCCO2) emission. Within the scope of the study, a primary school building is selected to be analysed. Through analysis, the total embodied and operational energy use and CO2 emission regarding the life cycle phase of the building is quantitatively defined and investigated in the framework of life cycle inventory. The paper concentrates on the operation and embodied energy consumption arising from the application of a variety of measures on the building envelope. An educational building with low LCCO2 emissions and LCEC in Turkey is proposed. To exemplify the approach, contributions are applied to a case study in Istanbul as a representative school building. The primary energy consumption of the case study building is calculated with a dynamic simulation tool, EnergyPlus. Afterwards, a sort of architectural energy efficient measures is implemented in the envelope while the lighting and mechanical systems remain constant. The energy used in the production and transportation of materials, which are the significant parts of the embodied energy, are taken into account as well.


2018 ◽  
Vol 10 (12) ◽  
pp. 4688
Author(s):  
Marina Nikolić Topalović ◽  
Milenko Stanković ◽  
Goran Ćirović ◽  
Dragan Pamučar

Research was conducted to indicate the impact of the increased flow of thermal insulation materials on the environment due to the implementation of the new regulations on energy efficiency of buildings. The regulations on energy efficiency of buildings in Serbia came into force on 30 September 2012 for all new buildings as well as for buildings in the process of rehabilitation and reconstruction. For that purpose, the carbon footprint was analyzed in three scenarios (BS, S1 and S2) for which the quantities of construction materials and processes were calculated. The life cycle analysis (LCA), which is the basis for analyzing the carbon life cycle (LCACO2), was used in this study. Carbon Calculator was used for measuring carbon footprint, and URSA program to calculate the operational energy. This study was done in two phases. In Phase 1, the embodied carbon was measured to evaluate short-term effects of the implementation of the new regulations. Phase 2 included the first 10 years of building exploitation to evaluate the long-term effects of the new regulations. The analysis was done for the period of 10 years, further adjustments to the regulations regarding energy efficiency of the buildings in Serbia are expected in accordance with EU directives. The study shows that, in the short-run, Scenario BS has the lowest embodied carbon. In the long-run, after 3.66 years, Scenario S2 becomes a better option regarding the impact on the environment. The study reveals the necessity to include embodied carbon together with the whole life carbon to estimation the impact of a building on the environment.


2014 ◽  
Vol 61 (3) ◽  
pp. 167-177 ◽  
Author(s):  
B. Mansoury ◽  
H. R. Tabatabaiefar

Abstract This study investigates the effectiveness of different energy retrofitting techniques and examines the impact of employing those methods on energy consumption of existing residential buildings. Based on the research findings, the most effective and practical method of retrofitting has been proposed in order to improve energy efficiency of existing buildings. In order to achieve this goal, an existing residential building has been simulated in FirstRate 5 software so as to determine the existing thermal performance of the building. Afterwards, considering sustainable design principles, different insulation layers, glazing, and construction materials have been employed to conduct a comprehensive thermal performance study. Based on the research outcomes, the best technique for increasing energy efficiency of existing buildings and reducing their environmental impact and footprint has been identified and proposed for practical purposes.


2021 ◽  
Author(s):  
Chafik Murad

Cantilevered concrete balcony slabs are being investigated in high-rise (MURBs) to control thermal bridging in terms of energy efficiency and thermal comfort where the use of a proprietary thermal break was the prime application as a solution to improving energy efficiency. This MRP investigated the thermal performance of using a lower U-value framed glazing condition and an insulated curb condition and developed assemblies in scenarios that were simulated in THERM, and focused on the technical performance of thermal comfort benefit of insulated curb condition of 12.7 mm thick EPS. Concrete surface temperatures were significantly increased in values from 4.8 °C to 9.6 °C and from 6.2 °C to 10.0 °C above balcony slab and from 6.7 °C to 10.8 °C below slab when an insulated curb condition was used in conventional scenarios and in a lower U-value framed condition scenario with no proprietary thermal break added. U-values are reduced 10% to 18% for the upper surface of balcony slab and 4% reduction of the overall U-values when an insulated curb condition is incorporated.


2020 ◽  
Author(s):  
MJ Booysen ◽  
J.A. Samuels ◽  
Sara Grobbelaar

South Africa’s private sector - under significant pressure to become energy efficient and employ sustainability principles - has long been implementing energy saving mechanisms. Unfortunately, there seems to exist many misplaced incentives in South Africa's public sector that prevent it from embracing energy-efficient technology. With the falling cost of LED lighting and the rising cost of electricity, however, conversions are increasingly cost efficient. Effecting these changes are increasingly urgent given the national utility-imposed rolling blackouts and climate change concerns. The primary education sector is a particularly attractive test case, since money saved on utilities can be allocated to desperately needed value-adding services in schools. From a technical perspective, however, the cost-benefit of replacements and the range of options facing decision makers could be overwhelming. To assess the impact of replacing fluorescent lights with LED lights at schools in South Africa, we propose a model that draws on smart metering data, a bench-test assessment of available LED lights and tariff rates. The model was validated with field tests at three schools and used to assess the impact at seven local schools. The results show that the setup cost differs substantially from the life-cycle cost, and that buying the cheapest lights could prove to be the costliest decision over the light's life cycle. The results also show that lights contribute from 42% to 57% of electricity expenditure, and that monetary savings of 21% to 39% are achievable by replacing fluorescent tubes with the most efficient LED lighting option available.


2021 ◽  
Author(s):  
Chafik Murad

Cantilevered concrete balcony slabs are being investigated in high-rise (MURBs) to control thermal bridging in terms of energy efficiency and thermal comfort where the use of a proprietary thermal break was the prime application as a solution to improving energy efficiency. This MRP investigated the thermal performance of using a lower U-value framed glazing condition and an insulated curb condition and developed assemblies in scenarios that were simulated in THERM, and focused on the technical performance of thermal comfort benefit of insulated curb condition of 12.7 mm thick EPS. Concrete surface temperatures were significantly increased in values from 4.8 °C to 9.6 °C and from 6.2 °C to 10.0 °C above balcony slab and from 6.7 °C to 10.8 °C below slab when an insulated curb condition was used in conventional scenarios and in a lower U-value framed condition scenario with no proprietary thermal break added. U-values are reduced 10% to 18% for the upper surface of balcony slab and 4% reduction of the overall U-values when an insulated curb condition is incorporated.


Author(s):  
V. Russo ◽  
A. E. Strever ◽  
H. J. Ponstein

Abstract Purpose Following the urgency to curb environmental impacts across all sectors globally, this is the first life cycle assessment of different wine grape farming practices suitable for commercial conventional production in South Africa, aiming at better understanding the potentials to reduce adverse effects on the environment and on human health. Methods An attributional life cycle assessment was conducted on eight different scenarios that reduce the inputs of herbicides and insecticides compared against a business as usual (BAU) scenario. We assess several impact categories based on ReCiPe, namely global warming potential, terrestrial acidification, freshwater eutrophication, terrestrial toxicity, freshwater toxicity, marine toxicity, human carcinogenic toxicity and human non-carcinogenic toxicity, human health and ecosystems. A water footprint assessment based on the AWARE method accounts for potential impacts within the watershed. Results and discussion Results show that in our impact assessment, more sustainable farming practices do not always outperform the BAU scenario, which relies on synthetic fertiliser and agrochemicals. As a main trend, most of the impact categories were dominated by energy requirements of wine grape production in an irrigated vineyard, namely the usage of electricity for irrigation pumps and diesel for agricultural machinery. The most favourable scenario across the impact categories provided a low diesel usage, strongly reduced herbicides and the absence of insecticides as it applied cover crops and an integrated pest management. Pesticides and heavy metals contained in agrochemicals are the main contributors to emissions to soil that affected the toxicity categories and impose a risk on human health, which is particularly relevant for the manual labour-intensive South African wine sector. However, we suggest that impacts of agrochemicals on human health and the environment are undervalued in the assessment. The 70% reduction of toxic agrochemicals such as Glyphosate and Paraquat and the 100% reduction of Chlorpyriphos in vineyards hardly affected the model results for human and ecotoxicity. Our concerns are magnified by the fact that manual labour plays a substantial role in South African vineyards, increasing the exposure of humans to these toxic chemicals at their workplace. Conclusions A more sustainable wine grape production is possible when shifting to integrated grape production practices that reduce the inputs of agrochemicals. Further, improved water and related electricity management through drip irrigation, deficit irrigation and photovoltaic-powered irrigation is recommendable, relieving stress on local water bodies, enhancing drought-preparedness planning and curbing CO2 emissions embodied in products.


Arsitektura ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 129
Author(s):  
Sri Yuliani ◽  
Wiwik Setyaningsih

<p class="Abstract"><em>The surface temperature of the building material may release a heat load in the micro-environment. The largest building envelope receives the heat load of solar radiation is the roof. The strategic roof position at the top of the building has the opportunity to radiate heat received into the environment. Heat emissions lead to rising temperatures, so it is necessary to lower the temperature in micro-environment. When the heat of the building is not lowered will lead to an increase in the urban heat island (UHI). The objective of the study was to find the relationship between the thermal performance of the roof of the building and the energy efficiency in the high-rise building, in order to establish efficient thermal comfort. The research method uses experimental way in real model which is in Surakarta City, as humid tropical climate area. The result of the study is a comparison of the heat performance of three roofing materials which would later recommend the criteria of energy efficient roof for high buildings.</em><em></em></p>


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 80 ◽  
Author(s):  
Ricardo Ramírez-Villegas ◽  
Ola Eriksson ◽  
Thomas Olofsson

The aim of this study is to assess how the use of fossil and nuclear power in different renovation scenarios affects the environmental impacts of a multi-family dwelling in Sweden, and how changes in the electricity production with different energy carriers affect the environmental impact. In line with the Paris Agreement, the European Union has set an agenda to reduce greenhouse gas emissions by means of energy efficiency in buildings. It is estimated that by the year 2050, 80% of Europe’s population will be living in buildings that already exist. This means it is important for the European Union to renovate buildings to improve energy efficiency. In this study, eight renovation scenarios, using six different Northern European electricity mixes, were analyzed using the standard of the European Committee for Standardization for life cycle assessment of buildings. This study covers all life cycle steps from cradle to grave. The renovation scenarios include combinations of photovoltaics, geothermal heat pumps, heat recovery ventilation, and improvement of the building envelope. The results show that while in some electricity mixes a reduction in the global warming potential can be achieved, it can be at the expense of an increase in radioactive waste production, and, in mixes with a high share of fossil fuels, the global warming potential of the scenarios increases with time, compared with that of the original building. It also shows that in most electricity mixes, scenarios that reduce the active heat demand of the building end up in reducing both the global warming potential and radioactive waste, making them less sensitive to changes in the energy system.


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