scholarly journals OPERATIONAL ENERGY SAVING IN BUILDINGS: A COMPARISON OF GREEN VS CONVENTIONAL WALL

2021 ◽  
Author(s):  
U.G.D. Madushika ◽  
◽  
T. Ramachandra ◽  
N. Zainudeen ◽  
◽  
...  

The green wall concept has been introduced as one of the solutions to reduce energy demand for ventilation requirements while improving the natural vegetation in dense urban areas. Past studies revealed that the energy-saving of green walls can vary substantially, from 35% to 90% across countries such as United Kingdom (UK), Canada, Russia, Greece, China, Saudi Arabia, India, and Brazil. Given these differences in energy saving of green walls due to climatic conditions and other reasons, direct application of such findings to the Sri Lankan context is questionable. Therefore, this study aimed to assess the thermal performance of green wall applications in Sri Lanka through a case study analysis of an indirect green façade with a comparative conventional wall. The required data were extracted through on-site temperature measurements from different points of both the exterior and interior wall surfaces of each building in different time intervals per day for a period of fourteen days spanning from October to November. The analysis shows that the green walls contribute to 21% - 36% of temperature difference compared to the conventional wall. Eventually, this results in 0.06 kWh of energy-saving per m2 of wall area, and thereby green walls contribute to the 80% energy saving for ventilation requirements. Hence, the study recommends that the use of green walls can be considered as one of the energy efficiency solutions while improving natural vegetation in tropical climatic cities and absorbing other benefits of green walls.

2016 ◽  
Vol 18 (1) ◽  
pp. 104 ◽  
Author(s):  
R. Djedjig ◽  
M. El Ganaoui ◽  
R. Belarbi ◽  
R. Bennacer

Green walls and green roofs are innovative construction technologies involving the use environmentally friendly materials. In addition to their aesthetical and environmental benefits, green walls have significant thermal effects on buildings and heat islands within high-density urban areas. In this paper, we study the impact of an innovative green wall system on building energy performance. These green walls have specific composition and particular geometry that can lead to higher thermal performances and therefore more significant impact on building energy performance. The development, validation and prior integration of a hygrothermal green wall model in a transient building simulation tool make possible the assessment of the energy performance of buildings when covered by green walls. The used model was adapted to be the particular forms and composition of the studied green walls. In parallel, this type of green walls has been installed on a one tenth building mockup to be experimented. The aim of the experiment is to measure the thermal effects and to calibrate some parameters of the numerical model. The results highlight the thermal benefits of this kind of green walls in summer condition. They reduce annual energy demand of building up to 37% for hot climates.


2018 ◽  
Author(s):  
Sara Torabi Moghadam ◽  
Silvia Coccolo ◽  
Guglielmina Mutani ◽  
Patrizia Lombardi ◽  
Jean Louis Scartezzini ◽  
...  

The spatial visualization is a very useful tool to help decision-makers in the urban planning process to create future energy transition strategies, implementing energy efficiency and renewable energy technologies in the context of sustainable cities. Statistical methods are often used to understand the driving parameters of energy consumption but rarely used to evaluate future urban renovation scenarios. Simulating whole cities using energy demand softwares can be very extensive in terms of computer resources and data collection. A new methodology, using city archetypes is proposed, here, to simulate the energy consumption of urban areas including urban energy planning scenarios. The objective of this paper is to present an innovative solution for the computation and visualization of energy saving at the city scale.The energy demand of cities, as well as the micro-climatic conditions, are calculated by using a simplified 3D model designed as function of the city urban geometrical and physical characteristics. Data are extracted from a GIS database that was used in a previous study. In this paper, we showed how the number of buildings to be simulated can be drastically reduced without affecting the accuracy of the results. This model is then used to evaluate the influence of two set of renovation solutions. The energy consumption are then integrated back in the GIS to identify the areas in the city where refurbishment works are needed more rapidly. The city of Settimo Torinese (Italy) is used as a demonstrator for the proposed methodology, which can be applied to all cities worldwide with limited amount of information.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2912 ◽  
Author(s):  
Jiayu Li ◽  
Bohong Zheng ◽  
Wenquan Shen ◽  
Yanfen Xiang ◽  
Xiao Chen ◽  
...  

To mitigate the urban heat island (UHI) and release the low carbon potential of green walls, we analyzed the cooling and energy-saving performance of different green wall designs. Envi-met was applied as the main simulation tool, and a pedestrian street named Yuhou Street was selected as the study object. Four designs of walls were summarized and simulated, demonstrating the living wall system (LWS). Super soil had superiority in cooling and energy saving. Outdoor air temperature, indoor air temperature, outside wall surface temperature, and inside wall surface temperature were analyzed. Apart from the outdoor air temperature, the other three temperatures were all significantly affected by the design of green walls. Finally, energy savings in building cavities were determined. The indoor energy saving ratio of the LWS based on super soil reached 19.92%, followed by the LWS based on boxes at 15.37%, and green facades wall at 6.29%. The indoor cooling powers on this typical day showed that the cooling power of the LWS based on super soil was 8267.32 W, followed by the LWS based on boxes at 6381.57 W, and green facades wall at 2610.08 W. The results revealed the difference in cooling and energy-saving performance of different green walls in this typical hot summer area.


2016 ◽  
Vol 6 (2) ◽  
pp. 342-347 ◽  
Author(s):  
F. Masi ◽  
R. Bresciani ◽  
A. Rizzo ◽  
A. Edathoot ◽  
N. Patwardhan ◽  
...  

This paper describes a pilot installation of a green wall treating greywater from an office building in Pune, Maharashtra State (NaWaTech project). The pilot installation is located at the main entrance of the state agency responsible for water supply and sanitation. The experimental analysis is in two phases. First phase analysed the results from green walls filled only with LECA® (lightweight expanded clay aggregate). Since results from the first phase were not satisfactory, a second phase was developed. In the second phase, LECA plus sand and LECA plus coconut fibres were tested as porous media in order to increase residence times and consequently green wall treatment performance. The expected improvements in treatment efficiency have been confirmed by the wider range of observed removal rates between Phase I (chemical oxygen demand, COD, 16–20%) and Phase II (i.e. COD removal in the order of 14–86% and 7–80% for LECA-coconut and LECA-sand, respectively), denoting higher treatment potentialities for the new configurations. The obtained effluent quality was fulfilling the Indian law specifications for reuse in irrigation for all the analysed samples, while only the last samples collected during Phase II were showing an appropriate quality for reuse by flushing toilets.


Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 255
Author(s):  
Muataz Dhaif ◽  
André Stephan

In hot and humid climatic conditions, cooling tends to dominate building thermal energy use. Cooling loads can be reduced through the adoption of efficient building envelope materials, such as Structural Insulated Panels (SIPs). This study quantifies the life cycle cost and operational energy of a representative case-study house in Bahrain using SIPs and hollow concrete blocks (HCBs) for the envelope over a period of 50 years. Operational energy is calculated using a dynamic energy simulation tool, operational costs are calculated based on the energy demand and local tariff rates, and construction costs are estimated using market prices and quotations. The life cycle cost is quantified using the Net Present Cost technique. Results show that SIPs yield a 20.6% reduction in cooling energy use compared to HCBs. For SIP costs of 12 and 17 USD/m², the SIP house was cheaper throughout, or had a higher capital cost than the HCB house (breaking even in year 33), respectively. We propose policy recommendations with respect to material pricing, electricity tariffs, and energy efficiency, to improve the operational energy efficiency of houses in Bahrain and similar countries along the Arabian Peninsula.


2021 ◽  
Author(s):  
Victoria Miles ◽  
Igore Ezau

<p>Fragile northern high-latitude ecosystems are changing rapidly, driven by a warmer climate and extensive socio-economic development. These pressures lead to disruption of ecosystem functioning. Ecosystem productivity and phenology are indicators of ecosystem functioning. Ecosystem productivity changes such as “greening” or “browning” are highly dependent on local bioclimatic conditions. In this study, we evaluate the response of vegetation productivity in urban, semi-natural (urban–rural), and natural areas located in different bioclimatic conditions. The study is based on remote sensing data, geographic information systems (GIS), and statistical methods. We use moderate-resolution satellite spectroradiometer (MODIS) data from 2000–2019. The results show a high contrast in productivity between urban, semi-natural, and natural vegetation in different bioclimatic zones. The low productivity of urban vegetation contrasts with higher productive semi-natural and natural vegetation in the Atlantic and Middle boreal zones. However, in the Northern boreal zone, urban areas are the greenest and the productivity of urban vegetation corresponds to semi-natural and natural vegetation. The semi-natural vegetation shows similar productivity to natural in the Atlantic, but in the Middle boreal zone, we observe contrasting productivity. In the Northern boreal zone, the semi-natural vegetation more productive than natural. We conclude that in the colder climatic conditions, the anthropogenic impact has a positive effect on ecosystem productivity. The spatial heterogeneity of productivity indicates different reactions of certain types of vegetation, as well as local effects, which are clearly important against the background of the regional climate response. These factors need to be accounted for in developing adaptation strategies for northern urban areas.</p>


Author(s):  
А.В. Терешкин ◽  
А.Л. Калмыкова ◽  
Т.А. Андрушко

Вертикальное озеленение с участием различных видов лиан в современных условиях имеет важное эстетическое и санитарно-гигиеническое значение. Особо актуально решение вопросов обогащения флоры городских территорий лианами в степных районах в связи с бедным видовым составом и резким ухудшением экологической ситуации. Объектами исследований являлись 7 видов лиан, различных жизненных форм (однолетние, многолетние), произрастающие в населенных пунктах Саратовской области (Аткарск, Саратов). Цель исследований – изучение эколого-биологических особенностей и мелиоративных свойств лиан и выявление перспектив их использования в вертикальном озеленении селитебных территорий Саратовской области. В ходе исследования видового состава, были выявлены наиболее популярные виды однолетних лиан: ипомея красно-голубая (Ipomea tricolor (L.) Roth) и ипомея пурпурная (Ipomea purpurea (L.) Roth), горошек душистый (Lathyrus edoratus L.), настурция (Tropacolum peregrinum L.) и фасоль огненно-красная (Phaseolus coccineus). Большинство (70%) из них произрастают в местах ограниченного пользования. Изученные виды лиан в исследуемых регионах достигают средних природных показателей (при наличии надлежащего ухода), обладают хорошими показателями жизненного состояния, обильно цветут и плодоносят. При воздействии токсикантами различной концентрации на листовые пластинки лиан установлено их степень устойчивости. Выявлено, что однолетние лианы лучше использовать в декоративных целях, а не в санитарно-гигиенических. Сравнительная оценка однолетних видов с многолетними лианами (девичий виноград пятилисточковый и клематис тангутский) показывает устойчивость многолетних видов (в среднем на 3 балла - 40%). Разработаны варианты декоративных композиций с участием травянистых лиан. По степени декоративности выделены однолетние лианы – Ipomea tricolor, I. purpurea (37 – 41 балл), средней степенью отличаются – Lathyrus edoratus (33 балла), Tropacolum peregrinum (30 баллов) и Phaseolus coccineus (20 – 27 баллов). Преимущество многолетних лиан заключается в их устойчивости к резким изменениям климатических условий (на 40 %) по сравнению с однолетними формами. Поэтому они более предпочтительны для озеленения городской среды. Для усиления декоративного эффекта в сезонном аспекте рекомендуются сочетать расширение видового и формового разнообразия растений (многолетние и однолетние лианы, древесно-кустарниковая, цветочная растительность). Установлено, что природно-климатические условия зоны степи и лесостепи в пределах Саратовской области являются достаточно благоприятными для нормального роста и развития древесно-кустарниковой растительности, в том числе травянистых лиан. Таким образом, обоснованное применение древесных лиан в комплексе с традиционными видами насаждений позволит создать комфортные условия проживания населения, регулировать оптимальный температурный баланс и создавать благоприятные микроклиматические условия. Vertical gardening with different types of vines in modern conditions is important aesthetic and sanitary-hygienic value. It is especially important to address the issues of enrichment of the flora of urban areas with vines in the steppe regions due to poor species composition and a sharp deterioration of the ecological situation. The objects of research were 7 species of lianas, various life forms (annual, perennial), growing in the settlements of the Saratov region (Atkarsk, Saratov). The aim of the research is to study the ecological and biological features and reclamation properties of vines and identify the prospects for their use in vertical gardening residential areas of the Saratov region. In the study, species composition was the most popular species of annual vines: morning glory red-blue (Ipomea tricolor (L.) Roth) and purple morning glory (Ipomea purpurea (L.) Roth), the fragrant pea (Lathyrus edoratus L.), nasturtium (Tropacolum peregrinum L.) and runner beans (Phaseolus coccineus). Most (70%) of them grow in restricted areas. Studied species of vines in the study regions reach average natural performance (with proper care), have good indicators of vital condition, bloom abundantly and bear fruit. When exposed to toxicants of different concentrations on the leaf blades of vines established their degree of stability. It was revealed that the annual vines are better used for decorative purposes, and not in the sanitary-hygienic. A comparative assessment of annual species with perennial vines (maiden grapes and clematis Tangut) shows the stability of perennial species (an average of 3 points-40%). The options and decorative compositions with the participation of herbaceous vines. According to the degree of decoration of the allocated annual vine – Ipomea tricolor, I. purpurea (37 – 41 points), the average degree of differ – Lathyrus edoratus (33 points), Tropacolum peregrinum (30 points) and Phaseolus coccineus (20 to 27 points). The advantage of perennial vines is their resistance to sudden changes in climatic conditions (40 %) compared to annual forms. Therefore, they are more preferable for greening the urban environment. To enhance the decorative effect in the seasonal aspect, it is recommended to combine the expansion of species and form diversity of plants (perennial and annual lianas, tree and shrub, floral vegetation). It is established that the climatic conditions of the steppe and forest-steppe zone within the Saratov region are quite favorable for the normal growth and development of tree and shrub vegetation, including herbaceous lianas. Thus, the reasonable use of wood vines in combination with traditional types of plantings will create comfortable living conditions for the population, regulate the optimal temperature balance and create favorable microclimatic conditions.


Author(s):  
Martina Caruso ◽  
Rui Pinho ◽  
Federica Bianchi ◽  
Francesco Cavalieri ◽  
Maria Teresa Lemmo

AbstractA life cycle framework for a new integrated classification system for buildings and the identification of renovation strategies that lead to an optimal balance between reduction of seismic vulnerability and increase of energy efficiency, considering both economic losses and environmental impacts, is discussed through a parametric application to an exemplificative case-study building. Such framework accounts for the economic and environmental contributions of initial construction, operational energy consumption, earthquake-induced damage repair activities, retrofitting interventions, and demolition. One-off and annual monetary expenses and environmental impacts through the building life cycle are suggested as meaningful performance metrics to develop an integrated classification system for buildings and to identify the optimal renovation strategy leading to a combined reduction of economic and environmental impacts, depending on the climatic conditions and the seismic hazard at the site of interest. The illustrative application of the framework to an existing school building is then carried out, investigating alternative retrofitting solutions, including either sole structural retrofitting options or sole energy refurbishments, as well as integrated strategies that target both objectives, with a view to demonstrate its practicality and to explore its ensuing results. The influence of seismic hazard and climatic conditions is quantitatively investigated, by assuming the building to be located into different geographic locations.


Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 217
Author(s):  
Amela Ajanovic ◽  
Marina Siebenhofer ◽  
Reinhard Haas

Environmental problems such as air pollution and greenhouse gas emissions are especially challenging in urban areas. Electric mobility in different forms may be a solution. While in recent years a major focus was put on private electric vehicles, e-mobility in public transport is already a very well-established and mature technology with a long history. The core objective of this paper is to analyze the economics of e-mobility in the Austrian capital of Vienna and the corresponding impact on the environment. In this paper, the historical developments, policy framework and scenarios for the future development of mobility in Vienna up to 2030 are presented. A major result shows that in an ambitious scenario for the deployment of battery electric vehicles, the total energy demand in road transport can be reduced by about 60% in 2030 compared to 2018. The major conclusion is that the policies, especially subsidies and emission-free zones will have the largest impact on the future development of private and public e-mobility in Vienna. Regarding the environmental performance, the most important is to ensure that a very high share of electricity used for electric mobility is generated from renewable energy sources.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Junghyun Kim ◽  
Bom Kim ◽  
So Hyeon Bak ◽  
Yeon-Mok Oh ◽  
Woo Jin Kim

Abstract Background The clinical and radiological presentation of chronic obstructive pulmonary disease (COPD) is heterogenous depending on the characterized sources of inflammation. This study aimed to evaluate COPD phenotypes associated with specific dust exposure. Methods This study was designed to compare the characteristics, clinical outcomes and radiological findings between two prospective COPD cohorts representing two distinguishing regions in the Republic of Korea; COPD in Dusty Area (CODA) and the Korean Obstructive Lung Disease (KOLD) cohort. A total of 733 participants (n = 186 for CODA, and n = 547 for KOLD) were included finally. A multivariate analysis to compare lung function and computed tomography (CT) measurements of both cohort studies after adjusting for age, sex, education, body mass index, smoking status, and pack-year, Charlson comorbidity index, and frequency of exacerbation were performed by entering the level of FEV1(%), biomass exposure and COPD medication into the model in stepwise. Results The mean wall area (MWA, %) became significantly lower in COPD patients in KOLD from urban and metropolitan area than those in CODA cohort from cement dust area (mean ± standard deviation [SD]; 70.2 ± 1.21% in CODA vs. 66.8 ± 0.88% in KOLD, p = 0.028) after including FEV1 in the model. COPD subjects in KOLD cohort had higher CT-emphysema index (EI, 6.07 ± 3.06 in CODA vs. 20.0 ± 2.21 in KOLD, p < 0.001, respectively). The difference in the EI (%) was consistently significant even after further adjustment of FEV1 (6.12 ± 2.88% in CODA vs. 17.3 ± 2.10% in KOLD, p = 0.002, respectively). However, there was no difference in the ratio of mean lung density (MLD) between the two cohorts (p = 0.077). Additional adjustment for biomass parameters and medication for COPD did not alter the statistical significance after entering into the analysis with COPD medication. Conclusions Higher MWA and lower EI were observed in COPD patients from the region with dust exposure. These results suggest that the imaging phenotype of COPD is influenced by specific environmental exposure.


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