Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals Energy Conservation Potential of Economizer Controls Using Optimal Outdoor Air Fraction Based on Field Study

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5038
Author(s):  
Goopyo Hong ◽  
Chul Kim ◽  
Jun Hong
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Temperature Control ◽  
Energy Savings ◽  
Cooling System ◽  
Energy Performance ◽  
Outdoor Air ◽  
Humid Climate ◽  
Differential Enthalpy ◽  
The Impact

In commercial buildings, HVAC systems are becoming a primary driver of energy consumption, which already account for 45% of the total building energy consumption. In the previous literature, researchers have studied several energy conservation measures to reduce HVAC system energy consumption. One of the effective ways is an economizer in air-handling units. Therefore, this study quantified the impact of the outdoor air fraction by economizer control type in cooling system loads based on actual air-handling unit operation data in a hospital. The optimal outdoor air fraction and energy performance for economizer control types were calculated and analyzed. The result showed that economizer controls using optimal outdoor air fraction were up to 45% more efficient in cooling loads than existing HVAC operations in the hospital. The energy savings potential was 6–14% of the differential dry-bulb temperature control, 17–27% of the differential enthalpy control, 8–17% of the differential dry-bulb temperature and high-limit differential enthalpy control, and 16–27% of the differential enthalpy and high-limit differential dry-bulb temperature control compared to the no economizer control. The result of this study will contribute to providing a better understanding of economizer controls in the hospital when the building operates in hot-humid climate regions.

scholarly journals A MODEL OF A NEAR-ZERO ENERGY HOME (nzeh) USING PASSIVE DESIGN STRATEGIES AND PV TECHNOLOGY IN HOT CLIMATES

2016 ◽  
Vol 11 (1) ◽  
pp. 38-70 ◽  
Author(s):  
Ashraf T. Syed ◽  
Adel A. Abdou
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
Base Case ◽  
Solar Pv ◽  
Design Strategies ◽  
Zero Energy ◽  
Energy Potential ◽  
Housing Design ◽  
Passive Design

INTRODUCTION Recent development has seen a drastic increase in energy use trends in Saudi Arabian buildings leading to a demand for an effective course of action for energy conservation and production. A case study-based research initiative exploring near-zero energy potential in Saudi Arabia was undertaken. A 4-bedroom detached single-family faculty residence at King Fahd University of Petroleum and Minerals (KFUPM) representing common regional housing design trends was utilized. A base case simulation model of the house was developed and validated using short-term and real-time energy consumption data. Three sets of strategies: passive design strategies, representative codes and standards, and renewable technology were employed in the new design of the house. Passive strategies comprised a green roof, a ventilated wall system, a sloped roof, and insulation for thermal bridges. These alternatives helped reduce the annual energy consumption of the house by 17.2%. The most recent version of the International Energy Conservation Code (IECC 2012) was also incorporated along with ASHRAE Standard 62.2 for ventilation. The code and standard together reduced the annual energy consumption by 31.1%. Solar PV was then utilized to reduce grid utilization for the remainder of the house energy loads. This strategy provided 24.7% of the total energy consumed annually. A combination of strategies showed a 70.7% energy consumption reduction, thereby decreasing the energy index of the house from 162.9 to 47.7 kWh/m2/yr. The Zero Energy Building (ZEB) concepts and strategies utilized in this study demonstrate a socially responsible approach to achieving near-zero energy performance for an existing house.

scholarly journals Energy Efficiency of Novel Interior Surface Layer with Improved Thermal Characteristics and Its Effect on Hygrothermal Performance of Contemporary Building Envelopes

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2012 ◽  
Author(s):  
Jan Fořt ◽  
Jiří Šál ◽  
Jan Kočí ◽  
Robert Černý
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Computational Simulation ◽  
Thermal Characteristics ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Heat Fluxes ◽  
Passive Cooling ◽  
Fuel Price ◽  
Climate Conditions

Facing the consequences of climate change and fuel price rises, the achievement of the requirements for low-energy consumption of buildings has become a challenging issue. On top of that, increased demands on indoor hygrothermal conditions usually require the utilization of additional heating, ventilation, and air-conditioning (HVAC) systems to maintain a comfortable environment. On this account, several advanced and modern materials are widely investigated as a promising way for reduction of the buildings’ energy consumption including utilization of passive heating/cooling energy. However, the efficiency and suitability of passive strategies depending on several aspects including the influence of location, exterior climatic conditions, load-bearing materials used, and insulation materials applied. The main objective of this study consists of the investigation of the energy performance benefits gained by the utilization of advanced materials in plasters by computational modeling. Results obtained from a computational simulation reveal the capability of the studied passive cooling/heating methods on the moderation of indoor air quality together with the reduction of the diurnal temperature fluctuation. Achieved results disclose differences in terms of energy savings for even small variation in outdoor climate conditions. Additionally, the effectivity of passive cooling/heating alters considerably during the summer and winter periods. Based on the analysis of simulated heat fluxes, the potential energy savings related to improved thermal properties of the applied plaster layer reached up to 12.08% and thus represent an interesting passive solution towards energy sustainability to meet the criteria on modern buildings.

scholarly journals Retrofitting Rural Dwellings in Delta Region to Enhance Climate Change Mitigation in Egypt

2021 ◽  
Vol 25 (1) ◽  
pp. 136-150
Author(s):  
Ahmed Abouaiana
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Carbon Dioxide Emissions ◽  
Climate Change Mitigation ◽  
Assessment Tool ◽  
Energy Performance ◽  
Building Envelope ◽  
Delta Region ◽  
The Impact ◽  
Change Mitigation

Abstract The current rural dwelling pattern in the Delta in Egypt consumes much energy to achieve dwellers’ thermal comfort, increasing greenhouse gas emissions contributing to climate change threatening the region’s coastal parts. Therefore, this study highlights the potential of retrofitting the existing rural house utilizing pervasive construction technologies in diminishing energy consumption and carbon dioxide emissions as a climate change mitigation strategy. The current modern rural house and the construction typologies were characterized. This study selected a typical modern rural dwelling located in Al-Gharbia Governorate in the Delta region. The suggested retrofitting strategies were applied to the external building envelope. The impact on the annual energy consumption of cooling and heating loads was evaluated using an Energy Performance Assessment Tool (Design Builder). An optimal envelope configuration was suggested, then an economic assessment and an investigation to the local acceptance were provided. The results showed that using the commonly used construction techniques as a retrofitting strategy can plummet the energy consumption and CO2 emissions by one-third worthy of mentioning that the locals have shown a lack of interest in the investment in retrofitting their buildings as well as the economic model showed that the investment is not profitable. Further studies can be made by the author considering investigating different building typologies and engaging other stakeholders.

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

scholarly journals Investigating The Impact Of Thermal Mass Towards Energy Efficient Housing In Canada

2021 ◽  
Author(s):  
Tasnuva Ahmed
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Simulation Software ◽  
High Mass ◽  
Thermal Mass ◽  
Heating And Cooling ◽  
R Value ◽  
The Impact

The building industry is striving for environmental friendly and energy efficient facility developments, as we have used most of our natural resources for comfortable living. Therefore energy efficient houses are very significant to reduce energy consumption. Thermal mass can be used as one of the many techniques of energy efficiency in the housing industry. Thermal mass can store heat in it which can be released at a later time. This behaviour of thermal mass can play a significant role in heating and cooling energy consumption of houses. This study investigates the impact of thermal mass on heating and cooling energy performance of a detached house and a row attached house, which are two main types of housing in Canada. Energy Plus simulation software has been used in the study. Also the study includes two different climatic conditions in Canada, such as Toronto and Vancouver, to envision how thermal mass behaviour changes with climates. All these different studies show thermal mass has significant impact on reduced energy consumption (15% savings in Vancouver for CCHT house) and lowering indoor air temperature. Other strategies such as insulation high R value, increased south face glazing and reduced glazing U value have been integrated with thermal mass to see energy performance in both climates. It hows more energy reduction than only thermal mass strategy. For instance, in CCHT house insulation high R value with concrete high mass reduces maximum 27% of total energy for Vancouver location.

scholarly journals Influence of glazing type on energy efficiency of industrial buildings in the process of revitalization: A case study

2019 ◽  
Vol 17 (1) ◽  
pp. 33-44
Author(s):  
Branko Slavkovic
Keyword(s):  
Comparative Analysis ◽  
Carbon Dioxide Emissions ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Industrial Building ◽  
Industrial Buildings ◽  
Double Skin ◽  
The Impact ◽  
The City

This paper examines the possibilities of improving the energy performance of an existing industrial building by application of the double skin fa?ade on the revitalization of the building envelope in the climatic conditions of the city Novi Pazar, Republic of Serbia. The aim is to examine the impact of choosing the type of glazing, in the processes of revitalization, on the energy needs of industrial buildings for heating and cooling, as well as the contribution of the measures implemented to improve the energy performance of the selected type and model of industrial building. The energy performance of buildings was obtained using the software DesignBuilder and EnergyPlus simulation platform, taking into account the parameters of required internal temperature and climate data for the Republic of Serbia. The comparative analysis of the results of energy simulation according to the criterion of achieving greater energy savings and reduced carbon dioxide emissions was performed. The methodological approach in this research involves creating revitalization scenarios of industrial buildings with a shed roof construction, selection of the specific building according to whose properties by numerical simulation possibilities for energy revitalization depletion were investigated and comparative analysis of the obtained results was performed. The primary objective of this research is to investigate the impact of choosing the type of glazing on the energy performance of industrial buildings with a shed roof construction and to determine the optimal approach to energy revitalization of existing industrial buildings with the implementation of the double skin fa?ade under the climatic conditions of the city Novi Pazar, Republic of Serbia. The results of this paper indicate the negative characteristics of the kopilit glass to solar gains, whose retention requires a large amount of heating energy. While replacing of kopilit glass with a low-energy glass increases the amount of energy required to cooling of the building. With this research, through various revitalization scenarios, it is also indicated that using a double skin fa?ade in the revitalization process of the selected building, has a very similar impact on reducing CO2 emissions regardless of the type of glazing choice.

scholarly journals Investigating The Impact Of Thermal Mass Towards Energy Efficient Housing In Canada

2021 ◽  
Author(s):  
Tasnuva Ahmed
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Simulation Software ◽  
High Mass ◽  
Thermal Mass ◽  
Heating And Cooling ◽  
R Value ◽  
The Impact

The building industry is striving for environmental friendly and energy efficient facility developments, as we have used most of our natural resources for comfortable living. Therefore energy efficient houses are very significant to reduce energy consumption. Thermal mass can be used as one of the many techniques of energy efficiency in the housing industry. Thermal mass can store heat in it which can be released at a later time. This behaviour of thermal mass can play a significant role in heating and cooling energy consumption of houses. This study investigates the impact of thermal mass on heating and cooling energy performance of a detached house and a row attached house, which are two main types of housing in Canada. Energy Plus simulation software has been used in the study. Also the study includes two different climatic conditions in Canada, such as Toronto and Vancouver, to envision how thermal mass behaviour changes with climates. All these different studies show thermal mass has significant impact on reduced energy consumption (15% savings in Vancouver for CCHT house) and lowering indoor air temperature. Other strategies such as insulation high R value, increased south face glazing and reduced glazing U value have been integrated with thermal mass to see energy performance in both climates. It hows more energy reduction than only thermal mass strategy. For instance, in CCHT house insulation high R value with concrete high mass reduces maximum 27% of total energy for Vancouver location.

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