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Article
Publication date: 24 June 2019

Christian Koranteng, Barbara Simons and Charles Essel

The ever-increasing demand and consumption of energy and the effects of global warming with its long-term comrade, climate change, is obvious today than ever before. In today’s…

Abstract

Purpose

The ever-increasing demand and consumption of energy and the effects of global warming with its long-term comrade, climate change, is obvious today than ever before. In today’s world, naturally-ventilated buildings hardly provide the satisfaction that occupants need and wish for. It’s on this backdrop that the study aims to investigate how responsive buildings on the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana campus are to its warm humid climate and assess students thermal comfort levels.

Design/methodology/approach

Quantitative approach was adopted for the study. Empirical investigation was carried out using the survey approach. In total, 14 buildings (offices, classrooms and halls of residences) were assessed using the Mahoney Tables. Again, subjective thermal perceptions of occupants in the halls of residences was sought. A total of 214 valid questionnaires were used for the analysis.

Findings

Adaptive principles like the Mahoney Tables are not followed in recent years. Even where these principles have been followed, indoor spaces were still found to be uncomfortable. In total, 58 per cent of the occupants in all the three halls of residence voted in the comfort band: an indication unacceptable sensations. Warm sensation votes (44 per cent) was more than cool sensation votes (29 per cent). In warm sensation, 39 per cent of the subjects preferred cooler environment. The occupants felt that opening windows and the use of fans could keep them comfortable. Moreover, 48 per cent of the subjects voted that their fans and windows were effective.

Originality/value

The papers contribution to the body of knowledge is the provision of empirical evidence in the field of adaptive designs and thermal comfort. There is a strong indication from the results that human activities in terms of blatant disregard for laid down design principles coupled with the worsening situation of global warming is making interior spaces ever uncomfortable.

Details

Journal of Engineering, Design and Technology , vol. 17 no. 5
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 9 August 2021

Christian Koranteng, Barbara Simons, Kwabena Abrokwa Gyimah and Jimmy Nkrumah

Accra, the capital city of Ghana, is seeing high-rise buildings springing up with extensive glazing. Given the challenges of the country concerning energy provision, guaranteeing…

Abstract

Purpose

Accra, the capital city of Ghana, is seeing high-rise buildings springing up with extensive glazing. Given the challenges of the country concerning energy provision, guaranteeing comfort in buildings and sustainability aspects, this trend is questionable and worrying in this pandemic era. Therefore, the purpose of this paper is to evaluate how glazing types and their properties could reduce cooling loads and provide comfort by following the recommendations set by the Ghana Green Building Council (GHGBC) after the Green Star of South Africa, as well as other references found in literature.

Design/methodology/approach

Indoor thermal conditions were monitored to evaluate prevailing indoor conditions. Using a simulation application, various options were probed based on the Green recommendations and others found in literature to improve thermal comfort within the structure. Moreover, a questionnaire survey with observation was undertaken with 250 architects to understand the basis of decisions taken when specifying glazing for buildings.

Findings

The results indicate that cooling loads increased by 2% when the GHGBC after the Green Star of South Africa recommendations were applied. However, the use of the recommendations of previous research conducted in Ghana could reduce cooling loads by 38% to save energy. Suggested strategies of air velocity up to 1.0 m/s as well as thermal mass, comfort ventilation, conventional dehumidification and air-conditioning were found to be means to improve indoor comfort. Furthermore, the architects revealed that around 40% of multi-storey buildings are 70%–100% glazed. Of all the buildings, 62.4% was found to be glazed with single pane windows, making them use so much energy in cooling. Additionally, the survey underlined the client’s preference, cost and functionality as the three main bases for the choice of glazing in multi-storey office buildings.

Originality/value

A significant contribution of this study to the body of knowledge is the provision of empirical evidence to support the fact that due to climate difference, each country needs to undertake more experimental research works to be able to come out with standards that work. Thus, the GHGBC after the Green Star of South Africa does not necessarily work within the climatic context of Ghana.

Details

Journal of Engineering, Design and Technology , vol. 21 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 15 September 2021

Christian Koranteng, David Nyame-Tawiah, Kwabena Abrokwa Gyimah and Barbara Simons

As the global population keeps increasing with its associated urbanisation and climate change issues being experienced in various degrees worldwide, there is the need to find…

Abstract

Purpose

As the global population keeps increasing with its associated urbanisation and climate change issues being experienced in various degrees worldwide, there is the need to find mitigating measures to improve thermal conditions within spaces. The study aimed to evaluate green roofs to determine whether they could provide thermal comfort within residential buildings.

Design/methodology/approach

Forty-two-year weather data were retrieved from the Kumasi weather station to establish the pattern of the climatic variables. Furthermore, an experiment was conducted by constructing test cells to determine the potential of vegetation/green roofs on temperature development within spaces. This approach led to a simulation-based exploration of the thermal performance of the test cells to probe variables that could lead to the reduction in temperature after the models in the software (design-builder) had been validated.

Findings

The results on the 42 years (1976–2018) weather data showed a significant (p = 0.05) mean temperature increment of 2.0 °C. The constructed test cell with Setcreasea purpurea (Purple Heart) vegetation showed an annual mean temperature reduction of 0.4 °C (p = 0.05). In addition, the exploration using the simulation application showed combinations of various soil depth (70–500 mm) and leaf area indices (leaf area index of 2–5) having a potential to lower indoor temperature by 1.5 °C and its associated reduction in energy use. The option of green roofs as a valuable alternative to conventional roofs, given their potential in mitigating climate change, must be encouraged. A survey of occupants in six selected neighbourhoods in Kumasi showed varying subjective perceptions of several green issues (24–98%) and increases in temperature values because of the loss of greenery in the city.

Originality/value

Empirical data that point to the significant reduction of indoor temperature values and a subsequent reduction in energy use have been unearthed. Therefore, built environment professionals together with city authorities could invest in these sustainable measures to help humanity.

Details

Open House International, vol. 47 no. 3
Type: Research Article
ISSN: 0168-2601

Keywords

Open Access
Article
Publication date: 10 August 2021

Christian Koranteng, Barbara Simons and Kwabena Abrokwa Gyimah

Given the climatic context and economic challenge of Ghana in its developmental strides, energy use of office buildings continues to be a task on the economy. Therefore, the study…

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Abstract

Purpose

Given the climatic context and economic challenge of Ghana in its developmental strides, energy use of office buildings continues to be a task on the economy. Therefore, the study was about finding measures that could reduce cooling loads in 10 office buildings. The paper presents the outcome of a long-term study of the thermal conditions in a selected number of office buildings in Accra and Kumasi, Ghana.

Design/methodology/approach

Through long-term monitoring of environmental data, the buildings were consequently modelled in a simulation application. Thereafter, a validation of the simulation models (using regression coefficients, r2 of 0.53–0.90) was undertaken towards finding measures to reduce cooling loads.

Findings

The results showed various potentials of efficient lighting, thermal mass, night ventilation, insulation to attic floors, efficient glazing, blind deployments, etc. in reducing cooling loads in the range of 2–17.5%. By combining the potential measures to study their synergistic effects on the loads, 35, 39 and 38% improvements were achieved for the low-rise, multi-storey and fully glazed office buildings.

Originality/value

These potential measures ought to be incorporated in the design, specification, construction and operation of Ghanaian office buildings to reduce the burden on the economy and the environment. Now more than ever, there is the need for climatic regions to come up with empirical data that could help relieve the world's economies from the post-pandemic stress.

Details

Frontiers in Engineering and Built Environment, vol. 1 no. 2
Type: Research Article
ISSN: 2634-2499

Keywords

Article
Publication date: 28 February 2023

Emmanuel Otchere-Darko, Laura Atuah, Richard Opoku and Christian Koranteng

Green roofs are strategies for the ecological intensification of cities and a measure of meeting some of the sustainable development goals (SDGs). They have widely been adopted as…

Abstract

Purpose

Green roofs are strategies for the ecological intensification of cities and a measure of meeting some of the sustainable development goals (SDGs). They have widely been adopted as an adaptation strategy against an urban heat island (UHI). However, they are conventionally soil-based making it difficult and expensive to adopt as a strategy for greening existing buildings (GEB). This paper, therefore, develops a novel green roof system using climbers for thermal-radiative performance. The paper explores the vitality of climbing species as a nature-based strategy for GEB, and for the ecological improvement of the predominantly used cool roofs in sub-Saharan Africa (SSA).

Design/methodology/approach

Simulation for the same building Kejetia Central Market (KCM) Redevelopment; the existing aluminium roof (AL), soil-based extensive green roof (GR1) and the proposed green roof using climbing plants (GR2) were performed using ENVI-met. The AL and GR1 were developed as reference models to evaluate and compare thermal-radiative performance of the conceptual model (GR2). The long wave radiation emission (Qlw), mean radiant temperature (MRT) and outdoor air temperature (Ta) of all three roofing systems were simulated under clear sky conditions to assess the performance and plant vitality considering water access, leaf temperature (Tf) and latent heat flux (LE0) of GR1 and GR2.

Findings

There was no short wave radiation (Qsw) absorption at the GR2 substrate since the climbers have no underlying soil mass, recording daily mean average Qlw emission of 435.17 Wm−2. The soil of GR1, however, absorbed Qsw of 390.11 Wm−2 and a Qlw emission of 16.20 wm−2 higher than the GR2. The AL recorded the lowest Qlw value of 75.43 Wm−2. Also, the stomatal resistance (rs) was higher in GR1 while GR2 recorded a higher average mean transpiration flux of 0.03 g/sm3. This indicates a higher chance of survival of the climbers. The Ta of GR2 recording 0.45°C lower than the GR1 could be a good UHI adaptation strategy.

Research limitations/implications

No previous research on climbers for green roof systems was found for comparison, so the KCM project provided a unique confluence of dynamic events including the opportunity for block-scale impact assessment of the proposed GEB strategy. Notwithstanding, the single case study allowed a focussed exploration of the novel theory of redefining green roof systems with climbers. Moreover, the simulation was computationally expensive, and engaging multiple case studies were found to be overly exhaustive to arrive at the same meaningful conclusion. As a novelty, therefore, this research provides an alternative theory to the soil-based green roof phenomenon.

Practical implications

The thermal-radiative performance of green roofs could be improved with the use of climbers. The reduction of the intensity of UHI would lead to improved thermal comfort and building energy savings. Also, very little dependence on the volume of soil would require little structural load consideration thereby leading not only to cheaper green roof construction but their higher demand, adoption and implementation in SSA and other low-income economies of the global south.

Social implications

The reduction of the consumption of topsoil and water for irrigation could avoid the negative environmental impacts of land degradation and pollution which have a deleterious impact on human health. This fulfils SDG 12 which seeks to ensure responsible consumption of products. This requires the need to advance the research for improvement and training of local built environment practitioners with new skills for installation to ensure social inclusiveness in the combat against the intractable forces of negative climate impacts.

Originality/value

Climbers are mostly known for green walls, but their innovative use for green roof systems has not been attempted and adopted; it could present a cost-effective strategy for the GEB. The proposed green roof system with climbers apart from becoming a successful strategy for UHI adaptation was also able to record an estimated 568% savings on topsoil consumption with an impact on the reduction of pollution from excavation. The research provides an initial insight into design options, potentials and limitations on the use of climbers for green roofs to guide future research and experimental verification.

Details

International Journal of Building Pathology and Adaptation, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-4708

Keywords

Article
Publication date: 12 January 2021

Christian Koranteng, Barbara Simons and Frederick Wireko Manu

Many countries the world over continue to grapple with issues of thermal discomfort both within and without – a condition that has arisen due to incessant urbanization, climate…

Abstract

Purpose

Many countries the world over continue to grapple with issues of thermal discomfort both within and without – a condition that has arisen due to incessant urbanization, climate change, among others. The current study focussed on assessing the level of thermal stress both in and outdoors towards finding measures to reduce overheating in spaces within the Savannah climatic region of Ghana through a four-stage approach.

Design/methodology/approach

A four-stage approach has been used for the study; thus, a thermal comfort analysis based on physiologically equivalent temperature (PET), overheating assessment, a subjective thermal responses/evaluation of residents and a simulation effort to improve comfort.

Findings

There was an indication of “moderate cold stress to slight cold stress” on the coolest day (28th December). On the warmest day (12th April), however, the indoor environment had exceedance and severity of overheating of at least 56% and 38-degree hours. The acceptable comfort range and comfort temperatures of occupants of buildings in the study area have been determined to be 25.5–33 °C by the thermal sensation survey. Meanwhile, the simulation showed that a 200% increase in thermal mass, exterior wall insulation and roof extension and insulation has the potential to generate a reduction of 18% in overheated hours.

Originality/value

The paper unearths the flagrant disregard for thermal comfort in an attempt of “copying blindly” architecture from Southern Ghana by the affluent within the Savannah Region. Again, data provided prove that indeed human activities have worsened the plight of inhabitants through materials as well as construction methods.

Details

Engineering, Construction and Architectural Management, vol. 28 no. 10
Type: Research Article
ISSN: 0969-9988

Keywords

Article
Publication date: 4 November 2014

Michael Nii Addy, Emmanuel Adinyira and Christian Koranteng

Building energy efficiency is an inescapable part of the solution to Africa's sustainable development; its implementation can result in cost effective ways that can contribute to…

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Abstract

Purpose

Building energy efficiency is an inescapable part of the solution to Africa's sustainable development; its implementation can result in cost effective ways that can contribute to economic and social development as well as environmental sustainability. Despite this, a number of factors including financial barriers and market barriers are perceived by policy makers and building designers to influence the efficient use of energy in buildings. The purpose of this paper is to investigate the perceptions of architects in relation to the challenges of building energy efficiency in Ghana.

Design/methodology/approach

From a review of pertinent literature 18 factors were identified as challenging. Empirical investigation was carried out using survey questionnaire. The consideration of overlapping aspects of the study largely motivated the use of factor analysis to analyse the data which made it possible to make scientific deductions and built explanations from the results.

Findings

The study derives five brands of uncorrelated variables that better explains challenges faced in implementing building energy efficiency in Ghana. These variables include financial barriers, information barrier, private sector participation, behavioural barriers and production barrier. The study provides insight on the contextual provision of realities faced in implementing building energy efficiency in Ghana.

Originality/value

Key contribution of the paper to the body of knowledge is manifested in the use of the principal component analysis. This has rigorously provided understanding into the complex structure and the relationship between the various knowledge areas of building energy efficiency barriers in Ghana.

Details

Structural Survey, vol. 32 no. 5
Type: Research Article
ISSN: 0263-080X

Keywords

Content available

Abstract

Details

Open House International, vol. 47 no. 3
Type: Research Article
ISSN: 0168-2601

Article
Publication date: 26 September 2022

Christian Nnaemeka Egwim, Hafiz Alaka, Oluwapelumi Oluwaseun Egunjobi, Alvaro Gomes and Iosif Mporas

This study aims to compare and evaluate the application of commonly used machine learning (ML) algorithms used to develop models for assessing energy efficiency of buildings.

Abstract

Purpose

This study aims to compare and evaluate the application of commonly used machine learning (ML) algorithms used to develop models for assessing energy efficiency of buildings.

Design/methodology/approach

This study foremostly combined building energy efficiency ratings from several data sources and used them to create predictive models using a variety of ML methods. Secondly, to test the hypothesis of ensemble techniques, this study designed a hybrid stacking ensemble approach based on the best performing bagging and boosting ensemble methods generated from its predictive analytics.

Findings

Based on performance evaluation metrics scores, the extra trees model was shown to be the best predictive model. More importantly, this study demonstrated that the cumulative result of ensemble ML algorithms is usually always better in terms of predicted accuracy than a single method. Finally, it was discovered that stacking is a superior ensemble approach for analysing building energy efficiency than bagging and boosting.

Research limitations/implications

While the proposed contemporary method of analysis is assumed to be applicable in assessing energy efficiency of buildings within the sector, the unique data transformation used in this study may not, as typical of any data driven model, be transferable to the data from other regions other than the UK.

Practical implications

This study aids in the initial selection of appropriate and high-performing ML algorithms for future analysis. This study also assists building managers, residents, government agencies and other stakeholders in better understanding contributing factors and making better decisions about building energy performance. Furthermore, this study will assist the general public in proactively identifying buildings with high energy demands, potentially lowering energy costs by promoting avoidance behaviour and assisting government agencies in making informed decisions about energy tariffs when this novel model is integrated into an energy monitoring system.

Originality/value

This study fills a gap in the lack of a reason for selecting appropriate ML algorithms for assessing building energy efficiency. More importantly, this study demonstrated that the cumulative result of ensemble ML algorithms is usually always better in terms of predicted accuracy than a single method.

Details

Journal of Engineering, Design and Technology , vol. 22 no. 4
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 18 May 2015

David Ansong, Gina Chowa and Bernice Korkor Adjabeng

Expanding access to financial services for the 70 percent of Ghanaians who are unbanked is critical. Bank branches have been the primary channel for financial service delivery…

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Abstract

Purpose

Expanding access to financial services for the 70 percent of Ghanaians who are unbanked is critical. Bank branches have been the primary channel for financial service delivery, but this may be changing because of technological innovations. Analysts believe branch-based banking still has a role in promoting financial inclusion. The purpose of this paper is to examine the pattern of bank branch presence across rural and urban Ghana; the disparities in the spatial distribution of domestic, foreign, and rural and community bank branches; and the district level characteristics associated with the pattern of spatial distribution of bank branches.

Design/methodology/approach

The study uses spatial analyst tools, geographically weighted Poisson regression, and data from Ghana’s banking sector to show the inequality in availability of branch-based services and to highlight the district and regional level differences in the determinants of branch allocation.

Findings

The study finds evidence of inequality in access to financial services. Physical bank branches are disproportionately more accessible in the urban south compared to the rural north. The study also finds that population size, percentage of urban residents, workforce size, and literacy level are associated with bank allocation but the results vary by district.

Practical implications

Branch banking needs modernization to continue to bring financial services in closer proximity. Development of physical and electronic infrastructure could attract financial institutions to serve deprived areas with significant concentration of unbanked populations.

Originality/value

Findings of the study point to the need for banks to re-envision branch banking technology to make branch banking more interactive. Banks need to find ways to fuse transferable elements of mobile phone banking into branch-based banking, not just to attract younger technology-savvy customers but also to help make operations more attractive, efficient, and cost effective.

Details

International Journal of Bank Marketing, vol. 33 no. 3
Type: Research Article
ISSN: 0265-2323

Keywords

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