Papers by Dr. NAGARAKJU KAJA
International journal of engineering research and technology, 2019
Global energy demand has been gradually increasing. As per IEA’s (International Energy agency) Gl... more Global energy demand has been gradually increasing. As per IEA’s (International Energy agency) Global Energy & CO2 Status Report 2017, the energy demand has increased from 0.9% in 2016 to 2.1 % in 2017. The demand is expected to increase by 80% from 2012-2040. Energy shortage and environmental concerns due to the exploitation of nonrenewable sources of energy has led the world to look up to alternate technologies to harvest energy. Currently, renewable sources of energy like wind, solar and hydropower sectors contribute to 24% of global electricity demand and is expected to rise to 31% by 2040. Prevalence of building automation, the need for wireless sensors which are autonomous has increased. Energy Scavenging is one such system which reduces the load on the primary energy system by reclaiming energy from the unused portion of energy which otherwise is lost in form of heat and sound, also eliminates the wiring network and maintenance required in case of monitoring sensors. In this ...
A Review of Energy Scavenging Methods & their Application in Built Space, 2019
Global energy demand has been gradually increasing. As per IEA's (International Energy agency) Gl... more Global energy demand has been gradually increasing. As per IEA's (International Energy agency) Global Energy & CO2 Status Report 2017, the energy demand has increased from 0.9% in 2016 to 2.1 % in 2017. The demand is expected to increase by 80% from 2012-2040. Energy shortage and environmental concerns due to the exploitation of nonrenewable sources of energy has led the world to look up to alternate technologies to harvest energy. Currently, renewable sources of energy like wind, solar and hydropower sectors contribute to 24% of global electricity demand and is expected to rise to 31% by 2040. Prevalence of building automation, the need for wireless sensors which are autonomous has increased. Energy Scavenging is one such system which reduces the load on the primary energy system by reclaiming energy from the unused portion of energy which otherwise is lost in form of heat and sound, also eliminates the wiring network and maintenance required in case of monitoring sensors. In this paper, current energy scavenging technologies are reviewed. The core objective of this paper is to focus on aspects concerning technology, planning and applicability of various scavenging methods, using set parameters like technology readiness, ease of installation, energy conversion efficiency and power output, in typical built forms and conclude with certain considerations to be made while application.
International Journal of Civil Engineering (IJCE) , 2017
India is one of the fast urbanizing countries in the world. Being a developing country, India's u... more India is one of the fast urbanizing countries in the world. Being a developing country, India's urban population is increasing and estimates forecasts that by 2041, urban population country reaches 50%. In this context it becomes important for the governments to provide adequate housing for all keeping in view of its liveability and affordability. But housing is one of the major contributors of Green house gases (GHG) with 12.5% GHG emissions attributed to buildings in India alone. Social housing is considered often as a burden by the local governments with the aspect of economic viability and time constraints, other important aspects like its impact on the environment or the carbon footprint it is going to create are being neglected. At this juncture, Sustainable and affordable social housing is the necessity for reducing its negative impacts on nature and also to give economical, healthy and environmental friendly housing for the people.
International journal of engineering technologies and management research, Jan 18, 2023
Construction processes and related activities have significantly aided in environmental pollution... more Construction processes and related activities have significantly aided in environmental pollution and degradation of environment, deforestation, and other environmental issues. Construction operations have a negative influence on the environment because of waste creation, consumption of resources, noise pollution, air pollution from construction dust, and foul odors from huge diesel-powered construction equipment and vehicles used for transporting materials. This study's objective is to evaluate how construction affects the environment in order to provide solutions for mitigation and strategies for enforcement. To acquire information from primary sources, a literature review was conducted. Although all these effects cannot be eliminated, but various mitigation strategies, such as Environmental Management System (EMS), Environmental Impact Assessment (EIA), Quantitative Risk Assessment (QRA), Green Building (sustainable construction), and Environmental Protection Agency (EPA) can be used. As a result, the government and construction stakeholders should make a conscious effort to effectively integrate and start enforcing the present approaches/initiatives during the construction processes. These measures should be monitored from start to finish and legislative laws should be formulated in order to spell out punishment for the scenarios of violations. It is also advised that construction stakeholders become more aware of, and learn about, the environmental implications of building construction operations.
The essence of human life is qualitatively and quantitatively affected by climate change issues l... more The essence of human life is qualitatively and quantitatively affected by climate change issues like rise in sea level, increase in surface air temperature, abnormal monsoon, severe storm incidence, changes in precipitation and humidity etc. The coastal zones would be the first to be affected, which are highly populated because of fertile soil, opportunities for the development of the fishing and shipping industries and ease of transportation. The cultural heritage sites of the world are also exposed to the threat of changing climatic factors. The ancient structures were designed for a specific local climate but the migration of pests, increasing sea levels, increased acidity and salinity of seawater , etc. threatens many coastal heritage sites today(Climate change and World Heritage,2006). Climate change will either cause direct physical damage to the built heritage, or will affect the society associated with it which will lead to their migration. This paper aims to study and discu...
Indian Journal of Science and Technology, Nov 20, 2019
Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor... more Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor space. Comfort conditions of indoor spaces are influenced by parameters like air movement, humidity, air temperature, etc. The aim of this research is to assess the air movement preferences by the occupants in classrooms of the selected higher education institutes in hot humid climate of India. Methods/statistical analysis: Surveys were conducted in all the three seasons of the year as per ASHRAE standard procedures. Environmental variables were measured in classrooms while questionnaires were distributed to the occupants simultaneously. A total of 361 students were surveyed with 1444 data sets for the whole year. Findings: Outdoor (T out) temperatures were recorded and regression analysis has been done to find the relationship between the mean outdoor temperatures with the indoor operative temperatures (T op) recorded. The acceptance of air movement in classrooms during summer is 10-15.4%, in moderate season it is 5.6-30% and during winter it is up to 58%. Improvements/application: This study enables to understand the influence of air movement preference on occupant's thermal comfort in classrooms of hot and humid climate of India. This will help in creating a comfortable environment in classrooms of higher education through placement and designing of openings for increased air movement thereby improving the thermal comfort conditions. This research assessed the movement of air in the classrooms of higher education and the occupants air movement preference for thermal comfort. This study is a starting point for the adaptive thermal comfort research in hot and humid climate of Vijayawada region.
Indian Journal of Science and Technology
Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor... more Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor space. Comfort conditions of indoor spaces are influenced by parameters like air movement, humidity, air temperature, etc. The aim of this research is to assess the air movement preferences by the occupants in classrooms of the selected higher education institutes in hot humid climate of India. Methods/statistical analysis: Surveys were conducted in all the three seasons of the year as per ASHRAE standard procedures. Environmental variables were measured in classrooms while questionnaires were distributed to the occupants simultaneously. A total of 361 students were surveyed with 1444 data sets for the whole year. Findings: Outdoor (Tout) temperatures were recorded and regression analysis has been done to find the relationship between the mean outdoor temperatures with the indoor operative temperatures (Top) recorded. The acceptance of air movement in classrooms during summer is 10–15.4%, in moderate season it is 5.6–30% and during winter it is up to 58%. Improvements/application: This study enables to understand the influence of air movement preference on occupant’s thermal comfort in classrooms of hot and humid climate of India. This will help in creating a comfortable environment in classrooms of higher education through placement and designing of openings for increased air movement thereby improving the thermal comfort conditions. This research assessed the movement of air in the classrooms of higher education and the occupants air movement preference for thermal comfort. This study is a starting point for the adaptive thermal comfort research in hot and humid climate of Vijayawada region
Indian Journal of Science and Technology, 2019
Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor... more Background and objectives: Thermal comfort is very essential for a comfortable stay in any indoor space. Comfort
conditions of indoor spaces are influenced by parameters like air movement, humidity, air temperature, etc. The aim of
this research is to assess the air movement preferences by the occupants in classrooms of the selected higher education
institutes in hot humid climate of India. Methods/statistical analysis: Surveys were conducted in all the three seasons of
the year as per ASHRAE standard procedures. Environmental variables were measured in classrooms while questionnaires
were distributed to the occupants simultaneously. A total of 361 students were surveyed with 1444 data sets for the whole
year. Findings: Outdoor (Tout) temperatures were recorded and regression analysis has been done to find the relationship
between the mean outdoor temperatures with the indoor operative temperatures (Top) recorded. The acceptance of air
movement in classrooms during summer is 10–15.4%, in moderate season it is 5.6–30% and during winter it is up to 58%.
Improvements/application: This study enables to understand the influence of air movement preference on occupant’s
thermal comfort in classrooms of hot and humid climate of India. This will help in creating a comfortable environment
in classrooms of higher education through placement and designing of openings for increased air movement thereby
improving the thermal comfort conditions. This research assessed the movement of air in the classrooms of higher
education and the occupants air movement preference for thermal comfort. This study is a starting point for the adaptive
thermal comfort research in hot and humid climate of Vijayawada region
ACCU -Nara International Correspondent, UNESCO, 2017
This paper is about the conservation process undertaken to conserve the 18th century Majlis-e-Aar... more This paper is about the conservation process undertaken to conserve the 18th century Majlis-e-Aaraish-e-Balda (City Improvement Board) building of the Nizam era in Hyderabad. The building boasts of an Indo Saracenic style of architecture comprising of a single storey made up of granite & lime mortar. The restoration works were completed with an approximate spending of five million. This project was awarded the IIA - Asian Paints Royale “Gold Leaf Award” for Excellence in Architecture under Heritage and Restoration category. Considering the rapid commercialization and growth of the present times, this article tries to bring out the need of the world for protecting the heritage structures that we have inherited from our ancestors and which have challenged the test of time like the case of the CIB building in Hyderabad.
Research has shown that increased temperatures and low ventilation rates in classrooms can have n... more Research has shown that increased temperatures and low ventilation rates in classrooms can have negative impacts on work performance and health of the students. Its known fact that the better thermal comfort conditions in any space will have positive effects on the wellbeing of the persons using it. The major factors affecting thermal comfort are both environmental and personal. Environmental factors include air temperature, radiant temperature, air velocity and humidity. Personal factors include clothing insulation and metabolic heat. Movement of air is one of the important factors influencing thermal comfort of a space. This paper discusses about the relevance of increased air movement at higher indoor temperatures and humidity, and how it can improve thermal comfort conditions in a class room. A class room of an Institution has been chosen to test the point.
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Papers by Dr. NAGARAKJU KAJA
conditions of indoor spaces are influenced by parameters like air movement, humidity, air temperature, etc. The aim of
this research is to assess the air movement preferences by the occupants in classrooms of the selected higher education
institutes in hot humid climate of India. Methods/statistical analysis: Surveys were conducted in all the three seasons of
the year as per ASHRAE standard procedures. Environmental variables were measured in classrooms while questionnaires
were distributed to the occupants simultaneously. A total of 361 students were surveyed with 1444 data sets for the whole
year. Findings: Outdoor (Tout) temperatures were recorded and regression analysis has been done to find the relationship
between the mean outdoor temperatures with the indoor operative temperatures (Top) recorded. The acceptance of air
movement in classrooms during summer is 10–15.4%, in moderate season it is 5.6–30% and during winter it is up to 58%.
Improvements/application: This study enables to understand the influence of air movement preference on occupant’s
thermal comfort in classrooms of hot and humid climate of India. This will help in creating a comfortable environment
in classrooms of higher education through placement and designing of openings for increased air movement thereby
improving the thermal comfort conditions. This research assessed the movement of air in the classrooms of higher
education and the occupants air movement preference for thermal comfort. This study is a starting point for the adaptive
thermal comfort research in hot and humid climate of Vijayawada region
conditions of indoor spaces are influenced by parameters like air movement, humidity, air temperature, etc. The aim of
this research is to assess the air movement preferences by the occupants in classrooms of the selected higher education
institutes in hot humid climate of India. Methods/statistical analysis: Surveys were conducted in all the three seasons of
the year as per ASHRAE standard procedures. Environmental variables were measured in classrooms while questionnaires
were distributed to the occupants simultaneously. A total of 361 students were surveyed with 1444 data sets for the whole
year. Findings: Outdoor (Tout) temperatures were recorded and regression analysis has been done to find the relationship
between the mean outdoor temperatures with the indoor operative temperatures (Top) recorded. The acceptance of air
movement in classrooms during summer is 10–15.4%, in moderate season it is 5.6–30% and during winter it is up to 58%.
Improvements/application: This study enables to understand the influence of air movement preference on occupant’s
thermal comfort in classrooms of hot and humid climate of India. This will help in creating a comfortable environment
in classrooms of higher education through placement and designing of openings for increased air movement thereby
improving the thermal comfort conditions. This research assessed the movement of air in the classrooms of higher
education and the occupants air movement preference for thermal comfort. This study is a starting point for the adaptive
thermal comfort research in hot and humid climate of Vijayawada region