John Onyango | University of Miami (original) (raw)

Papers by John Onyango

Proceedings of the 19th International CIB World Building Congress, Brisbane, May 6, 2013

Experience and lessons learned suggest that the most effective strategies will require designing ... more Experience and lessons learned suggest that the most effective strategies will require designing a number of responses at both the regional and local levels. Many efforts have underemphasized community-based research and have subsequently resulted in outcomes of climate models and scenarios that are too broad for effective planning and adaptation at local scales. There is a need for a 360 degree assessment of the critical issues based on a case study approach. The research presented in this paper investigates impact of projected

(Sea Level Rise (SLR) on representative historic buildings in coastal communities in the South East focusing specifically on St Augustine Florida and Savannah Georgia. Several lessons can be drawn from the natural and man-made artefacts in such historic cities. The
paper discusses specific ways through which such cities exemplify practical responses to the climate. This notwithstanding it is important to bear in mind that they have not been exposed to environmental conditions that are drastically being altered through climate change. There is a need for a 360 degree assessment of the critical issues. The discussion in this position paper culminates into a description of an emerging collaboration framework that is directed
at enabling stakeholders to perform such an assessment.

Proceedings of the 19th International CIB World Building Congress, Brisbane: Queensland University of Technology, May 6, 2013

The last decade brought about significant changes to the social and political relationships in ma... more The last decade brought about significant changes to the social and political relationships in many developing countries. In Sub-Saharan Africa, there was a movement for multi-party democracy while in North African and Middle-Eastern countries, an “Arab” spring toppled governments. Parallels can be drawn between the emerging community social needs for a say in decision-making and the social movements that occurred in the western world in late 1960s.
This paper argues that the research and academic community should be at the forefront of place making process in response to newly emerging social needs of empowerment. It looks at the urban design laboratory process at Carnegie Mellon University in the USA and proposes that the methods and strategies could fit the newly found democratic spaces in Africa and the Middle East.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference,, Oct 30, 2013

Buildings in the US account for almost 30% of total energy consumption. Most of this energy is us... more Buildings in the US account for almost 30% of total energy consumption. Most of this energy is used to provide a comfortable indoor environment in respect to the dynamic outdoor conditions. However, occupancy behavior can greatly influence the end use energy for lighting and even air-conditioning system. This paper presents a study that compares energy intensity use in two buildings in Miami, one build using traditional masonry wall construction and occupied by a family of three and other newly built using air-tight construction and with efficient HVAC equipment’s. It revealed that even though the new air tight building was more energy efficient in $, however, when volumetric EUI per person was taken into account, the gap was minimal with a three month average of less than 4.0%. It then raises questions on whether the extra costs involved in making building more efficient actually contributes to the high consumption or is it because of user behavior?

ZEMCH Network, Miami, Oct 30, 2013

Older buildings are especially vulnerable to climate change effect of temperature and humidity in... more Older buildings are especially vulnerable to climate change effect of temperature and humidity increases. Many countries have responded by changing policies that affect how new buildings is constructed leaving a larger pool of poorly performing existing buildings. There has been an increase in the use of living plants for both aesthetic as well as energy performances in buildings. This paper presents a study of the potentials in energy reduction and improvements in indoor environment by installing temporary living wall on the west façade of a sample unit model in October 2013 at the University of Miami during the summer of 2013.

ZEMCH Network, Oct 30, 2013

The quality of indoor environments (IE), in classrooms has been linked to student’s learning perf... more The quality of indoor environments (IE), in classrooms has been linked to student’s learning performance. However, relationship between IE and energy use intensity has barely been studied. The study presents results from 3 elementary schools in Miami, which examined the environmental characteristics that provided comfortable environment for students learning and correlated it to the occupancy activity patterns. In addition it used the charrette methodology the tease out perception of satisfaction with the IE and the adaptive responses where there was dissatisfaction.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami, Oct 30, 2013

The temperature and humidity levels in Florida are estimated to increase by 4-11° F by 2080 due t... more The temperature and humidity levels in Florida are estimated to increase by 4-11° F by 2080 due to effects of climate change. This will results in higher energy demands for cooling, increase in moisture indoor and growth in mold that will affect health of occupiers. This paper uses morphed probabilistic climate change data from National Oceanic and Atmospheric Administration, (NOAA) to define extreme climatic events that are then used to model worst-case scenario for impact on energy uses and IAQ environment for a sample of typical houses in Miami, Florida. Several possible adaptive response strategies are then model and analysed in Ecotect to examine the effects. The study suggests that strategies that reduced solar heat gain into the building such as shading devices; surface characteristics of walls and types of construction had a greater impact in mitigating against climate change.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami: , Oct 30, 2013

Buildings in the US account for almost 30% of total energy consumption. Most of this energy is us... more Buildings in the US account for almost 30% of total energy consumption. Most of this energy is used to provide a comfortable indoor environment in respect to the dynamic outdoor conditions. However, occupancy behavior can greatly influence the end use energy for lighting and even air-conditioning system. There is lack of data on energy consumption profile especially for educational building type where the studios seem to operate on 24-hour schedule through the semester without response to occupancy patterns. This paper presents the analysis of energy consumption and occupancy activities in architectural studio at the University of Miami during the peak summer cooling period. The study revealed disconnect between actual occupancy, IAQ, energy consumption and universities facilities management system. It concludes by suggesting adaptive steps that could be used to realign the consumption with sustainable agenda at the University.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami: ZEMCH Network; (chapter contribution), Oct 30, 2013

"A LEED (Leadership in Energy and Environmental Design) is touted to produce buildings that are g... more "A LEED (Leadership in Energy and Environmental Design) is touted to produce buildings that are green in terms of energy efficiency, however a study on energy use in LEED certified commercial buildings gave mixed results and in another study no reduction at all. Both studies had concentrated on a database of commercial buildings with little having examined consumption patterns in residential buildings. The research proposes to examine the cost intensity of energy use in LEED certified residential buildings in the USA and what was the impact on household finances of the occupier’s. According to USGBC homes with LEED certification are resource efficient; healthy for the occupants and energy efficient consuming between 20 and 30% less energy than a home built to conventional standards. However literature on those claims are scanty, and have not included the possible economic costs of health implications.

The available literature on performance of LEED certified buildings energy use was 25–30% better than the national average. The report has been criticized for lack of a robust methodology as it relied on voluntary submission hence created a biased sample; the comparisons were not on apple for apple basis as they used median energy use intensity (EUI) versus mean EUI for the conventional buildings. The study used the database that came from the NBI study and found that LEED mean EUI to be from 18% to 39% lower than for matching non-LEED buildings. However, other authors used the same database and came to different conclusions suggesting a need for further study and analysis of the results. He argued that LEED-certification did not on average produce buildings that lower energy consumption both at the source and at the production point, though he acknowledged that they consumed less on site energy but to the tune of 10-17%.

The impact on household finances from the greening or energy efficient measure will be studied using the existing dataset from the Residential Energy Consumption Survey (RECS). The 2009 survey contains data from 12,000 households from 16 states that will be used to track the characteristics of energy consumption patterns, impact on health due to changes to the indoor air quality resulting from airtight construction and quantification of the impact on their finances.
"

The paper presents results from a study to evaluate the potential of waste heat recovery technolo... more The paper presents results from a study to evaluate the potential of waste heat recovery technology within the context of the commercial kitchen in Northern Ireland. The study involved both numerical simulation and measured data from five kitchens in Belfast that revealed heat recovery technology provided substantial economic and environmental savings. Utilising compact devices such as a spiral tube heat exchanger, these sustainable solutions can be easily retrofitted to enhance existing hot water systems. However, subsequent research should be conducted to broaden the scope of this study by complementing this technology with a solar panel or wind turbine. This would provide a more holistic and sustainable solution to the catering industry.

Abstract The construction industry is a very complex and competitive high-risk business as there... more Abstract
The construction industry is a very complex and competitive high-risk business as there are many parties involved in a project from the conception stage to the final erection of the asset. There are many problems, such as lack of cooperation, weak communication, and adversarial relationships that face the construction industry. Most of the researches focused on supply chain management practice were adopted in order to increase the innovation and to reduce the cost.

Partnering is one of the most practicable methods in effectively and efficiently delivering a project. However, previous researches have mainly concentrated on the upstream of the supply chain, and little attention has been paid to the small and medium-size enterprises (SMEs) that play an important role in the downstream of the supply chain.

This paper reviews literature on the implementation of supply chain management partnering in Chinese and UK’s construction industry. It then presents and discusses research data collected from China and UK. The study revealed that within Chinese context, partner flexibility, and the ability to absorb and effectively manage risks were most important factors. However within the UK context, the demonstrate-able capabilities of the partners as one of the key influencing factors.

Keywords: Partnering, supply-chain management, upstream, SMEs, China, UK

Dubai, the second largest city of the United Arab Emirates, is a fast-growing hub with increasing... more Dubai, the second largest city of the United Arab Emirates, is a fast-growing hub with increasing need for infrastructure, housing and public facilities. Dubai is trying to market itself as an attractive holiday destination, and has seen the launching and building of large-scale planned communities, some of which are located on reclaimed land along the city's coast line. This paper reviews Dubai's green building agenda by examining the scale and typologies of new and planned low-carbon projects, and discusses the potential of renewable sources of energy that can reduce the country's dependence on fossil fuels and improve long-term sustainability. The potentials of solar energy, wind power and geo-thermal energy in Dubai and the United Arab Emirates in general are assessed.

The US government has set a target of reducing CO2 emissions by 20% below the 2005 targets by the... more The US government has set a target of reducing CO2 emissions by 20% below the 2005 targets by the year 2020. Literature review reveals that residential buildings contribute over 20% of the total emissions mainly used for space heating, cooling, water heating and lighting. In hot humid climates, the concern is mainly for cooling and hot water that account for over 50% of the total residential energy consumption in South Florida as pointed out by Fairey and Parker [1].

In hot humid climates, the indoor temperatures normally follow the outdoor temperatures very closely, making comfortable conditions difficult to achieve without the use of active systems. The maximum average ground temperatures at a depth of 1.0m in South Florida 28°C according to Givoni [2] who examined the temperature profiles at 1m below ground in Florida for different seasons. The work suggested that there was potential to rely on the ground as a heat sink to reduce carbon dioxide emissions. Therefore an arrangement where hot humid air is passed through the tubes buried underground could not only cool it but also dehumidify a certain amount before discharging into the building.

The paper presents a study of biomimetic strategy that uses a ground coupled air-cooling system to reduce CO2 emissions. The results are from simulation using modified portable insulated office container unit of 6.096m x 2.438m x 2.438m. It has two windows and one door and is connected to 200mm diameter plastic tubes buried underground. The tubes are laid in a slope to allow for any condensate to collect in a sump at the end of each tube. The ventilation is assumed constant through use of a small extract fan on one of the windows, thus maintain the air velocity. The arrangement is as illustrated in figure 1 below.
Keywords: Ground-coupled, cooling, simulation, carbon dioxide emissions, Hot-humid, Florida, biomimicry, nature

Teaching Documents by John Onyango

Proceedings of the 19th International CIB World Building Congress, Brisbane, May 6, 2013

Experience and lessons learned suggest that the most effective strategies will require designing ... more Experience and lessons learned suggest that the most effective strategies will require designing a number of responses at both the regional and local levels. Many efforts have underemphasized community-based research and have subsequently resulted in outcomes of climate models and scenarios that are too broad for effective planning and adaptation at local scales. There is a need for a 360 degree assessment of the critical issues based on a case study approach. The research presented in this paper investigates impact of projected

(Sea Level Rise (SLR) on representative historic buildings in coastal communities in the South East focusing specifically on St Augustine Florida and Savannah Georgia. Several lessons can be drawn from the natural and man-made artefacts in such historic cities. The
paper discusses specific ways through which such cities exemplify practical responses to the climate. This notwithstanding it is important to bear in mind that they have not been exposed to environmental conditions that are drastically being altered through climate change. There is a need for a 360 degree assessment of the critical issues. The discussion in this position paper culminates into a description of an emerging collaboration framework that is directed
at enabling stakeholders to perform such an assessment.

Proceedings of the 19th International CIB World Building Congress, Brisbane: Queensland University of Technology, May 6, 2013

The last decade brought about significant changes to the social and political relationships in ma... more The last decade brought about significant changes to the social and political relationships in many developing countries. In Sub-Saharan Africa, there was a movement for multi-party democracy while in North African and Middle-Eastern countries, an “Arab” spring toppled governments. Parallels can be drawn between the emerging community social needs for a say in decision-making and the social movements that occurred in the western world in late 1960s.
This paper argues that the research and academic community should be at the forefront of place making process in response to newly emerging social needs of empowerment. It looks at the urban design laboratory process at Carnegie Mellon University in the USA and proposes that the methods and strategies could fit the newly found democratic spaces in Africa and the Middle East.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference,, Oct 30, 2013

Buildings in the US account for almost 30% of total energy consumption. Most of this energy is us... more Buildings in the US account for almost 30% of total energy consumption. Most of this energy is used to provide a comfortable indoor environment in respect to the dynamic outdoor conditions. However, occupancy behavior can greatly influence the end use energy for lighting and even air-conditioning system. This paper presents a study that compares energy intensity use in two buildings in Miami, one build using traditional masonry wall construction and occupied by a family of three and other newly built using air-tight construction and with efficient HVAC equipment’s. It revealed that even though the new air tight building was more energy efficient in $, however, when volumetric EUI per person was taken into account, the gap was minimal with a three month average of less than 4.0%. It then raises questions on whether the extra costs involved in making building more efficient actually contributes to the high consumption or is it because of user behavior?

ZEMCH Network, Miami, Oct 30, 2013

Older buildings are especially vulnerable to climate change effect of temperature and humidity in... more Older buildings are especially vulnerable to climate change effect of temperature and humidity increases. Many countries have responded by changing policies that affect how new buildings is constructed leaving a larger pool of poorly performing existing buildings. There has been an increase in the use of living plants for both aesthetic as well as energy performances in buildings. This paper presents a study of the potentials in energy reduction and improvements in indoor environment by installing temporary living wall on the west façade of a sample unit model in October 2013 at the University of Miami during the summer of 2013.

ZEMCH Network, Oct 30, 2013

The quality of indoor environments (IE), in classrooms has been linked to student’s learning perf... more The quality of indoor environments (IE), in classrooms has been linked to student’s learning performance. However, relationship between IE and energy use intensity has barely been studied. The study presents results from 3 elementary schools in Miami, which examined the environmental characteristics that provided comfortable environment for students learning and correlated it to the occupancy activity patterns. In addition it used the charrette methodology the tease out perception of satisfaction with the IE and the adaptive responses where there was dissatisfaction.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami, Oct 30, 2013

The temperature and humidity levels in Florida are estimated to increase by 4-11° F by 2080 due t... more The temperature and humidity levels in Florida are estimated to increase by 4-11° F by 2080 due to effects of climate change. This will results in higher energy demands for cooling, increase in moisture indoor and growth in mold that will affect health of occupiers. This paper uses morphed probabilistic climate change data from National Oceanic and Atmospheric Administration, (NOAA) to define extreme climatic events that are then used to model worst-case scenario for impact on energy uses and IAQ environment for a sample of typical houses in Miami, Florida. Several possible adaptive response strategies are then model and analysed in Ecotect to examine the effects. The study suggests that strategies that reduced solar heat gain into the building such as shading devices; surface characteristics of walls and types of construction had a greater impact in mitigating against climate change.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami: , Oct 30, 2013

Buildings in the US account for almost 30% of total energy consumption. Most of this energy is us... more Buildings in the US account for almost 30% of total energy consumption. Most of this energy is used to provide a comfortable indoor environment in respect to the dynamic outdoor conditions. However, occupancy behavior can greatly influence the end use energy for lighting and even air-conditioning system. There is lack of data on energy consumption profile especially for educational building type where the studios seem to operate on 24-hour schedule through the semester without response to occupancy patterns. This paper presents the analysis of energy consumption and occupancy activities in architectural studio at the University of Miami during the peak summer cooling period. The study revealed disconnect between actual occupancy, IAQ, energy consumption and universities facilities management system. It concludes by suggesting adaptive steps that could be used to realign the consumption with sustainable agenda at the University.

“Visibility of Zero-Energy Buildings” e-Proceedings of the ZEMCH2013 International Conference, Miami: ZEMCH Network; (chapter contribution), Oct 30, 2013

"A LEED (Leadership in Energy and Environmental Design) is touted to produce buildings that are g... more "A LEED (Leadership in Energy and Environmental Design) is touted to produce buildings that are green in terms of energy efficiency, however a study on energy use in LEED certified commercial buildings gave mixed results and in another study no reduction at all. Both studies had concentrated on a database of commercial buildings with little having examined consumption patterns in residential buildings. The research proposes to examine the cost intensity of energy use in LEED certified residential buildings in the USA and what was the impact on household finances of the occupier’s. According to USGBC homes with LEED certification are resource efficient; healthy for the occupants and energy efficient consuming between 20 and 30% less energy than a home built to conventional standards. However literature on those claims are scanty, and have not included the possible economic costs of health implications.

The available literature on performance of LEED certified buildings energy use was 25–30% better than the national average. The report has been criticized for lack of a robust methodology as it relied on voluntary submission hence created a biased sample; the comparisons were not on apple for apple basis as they used median energy use intensity (EUI) versus mean EUI for the conventional buildings. The study used the database that came from the NBI study and found that LEED mean EUI to be from 18% to 39% lower than for matching non-LEED buildings. However, other authors used the same database and came to different conclusions suggesting a need for further study and analysis of the results. He argued that LEED-certification did not on average produce buildings that lower energy consumption both at the source and at the production point, though he acknowledged that they consumed less on site energy but to the tune of 10-17%.

The impact on household finances from the greening or energy efficient measure will be studied using the existing dataset from the Residential Energy Consumption Survey (RECS). The 2009 survey contains data from 12,000 households from 16 states that will be used to track the characteristics of energy consumption patterns, impact on health due to changes to the indoor air quality resulting from airtight construction and quantification of the impact on their finances.
"

The paper presents results from a study to evaluate the potential of waste heat recovery technolo... more The paper presents results from a study to evaluate the potential of waste heat recovery technology within the context of the commercial kitchen in Northern Ireland. The study involved both numerical simulation and measured data from five kitchens in Belfast that revealed heat recovery technology provided substantial economic and environmental savings. Utilising compact devices such as a spiral tube heat exchanger, these sustainable solutions can be easily retrofitted to enhance existing hot water systems. However, subsequent research should be conducted to broaden the scope of this study by complementing this technology with a solar panel or wind turbine. This would provide a more holistic and sustainable solution to the catering industry.

Abstract The construction industry is a very complex and competitive high-risk business as there... more Abstract
The construction industry is a very complex and competitive high-risk business as there are many parties involved in a project from the conception stage to the final erection of the asset. There are many problems, such as lack of cooperation, weak communication, and adversarial relationships that face the construction industry. Most of the researches focused on supply chain management practice were adopted in order to increase the innovation and to reduce the cost.

Partnering is one of the most practicable methods in effectively and efficiently delivering a project. However, previous researches have mainly concentrated on the upstream of the supply chain, and little attention has been paid to the small and medium-size enterprises (SMEs) that play an important role in the downstream of the supply chain.

This paper reviews literature on the implementation of supply chain management partnering in Chinese and UK’s construction industry. It then presents and discusses research data collected from China and UK. The study revealed that within Chinese context, partner flexibility, and the ability to absorb and effectively manage risks were most important factors. However within the UK context, the demonstrate-able capabilities of the partners as one of the key influencing factors.

Keywords: Partnering, supply-chain management, upstream, SMEs, China, UK

Dubai, the second largest city of the United Arab Emirates, is a fast-growing hub with increasing... more Dubai, the second largest city of the United Arab Emirates, is a fast-growing hub with increasing need for infrastructure, housing and public facilities. Dubai is trying to market itself as an attractive holiday destination, and has seen the launching and building of large-scale planned communities, some of which are located on reclaimed land along the city's coast line. This paper reviews Dubai's green building agenda by examining the scale and typologies of new and planned low-carbon projects, and discusses the potential of renewable sources of energy that can reduce the country's dependence on fossil fuels and improve long-term sustainability. The potentials of solar energy, wind power and geo-thermal energy in Dubai and the United Arab Emirates in general are assessed.

The US government has set a target of reducing CO2 emissions by 20% below the 2005 targets by the... more The US government has set a target of reducing CO2 emissions by 20% below the 2005 targets by the year 2020. Literature review reveals that residential buildings contribute over 20% of the total emissions mainly used for space heating, cooling, water heating and lighting. In hot humid climates, the concern is mainly for cooling and hot water that account for over 50% of the total residential energy consumption in South Florida as pointed out by Fairey and Parker [1].

In hot humid climates, the indoor temperatures normally follow the outdoor temperatures very closely, making comfortable conditions difficult to achieve without the use of active systems. The maximum average ground temperatures at a depth of 1.0m in South Florida 28°C according to Givoni [2] who examined the temperature profiles at 1m below ground in Florida for different seasons. The work suggested that there was potential to rely on the ground as a heat sink to reduce carbon dioxide emissions. Therefore an arrangement where hot humid air is passed through the tubes buried underground could not only cool it but also dehumidify a certain amount before discharging into the building.

The paper presents a study of biomimetic strategy that uses a ground coupled air-cooling system to reduce CO2 emissions. The results are from simulation using modified portable insulated office container unit of 6.096m x 2.438m x 2.438m. It has two windows and one door and is connected to 200mm diameter plastic tubes buried underground. The tubes are laid in a slope to allow for any condensate to collect in a sump at the end of each tube. The ventilation is assumed constant through use of a small extract fan on one of the windows, thus maintain the air velocity. The arrangement is as illustrated in figure 1 below.
Keywords: Ground-coupled, cooling, simulation, carbon dioxide emissions, Hot-humid, Florida, biomimicry, nature