Climate Composition Research Articles

Field Analysis of three different Silicon-based Technologies in Composite Climatic Condition

This paper investigates the performance of the photovoltaics based on the filtering techniques, performance monitoring metrics, and numerical methodologies at real outdoor conditions. The experimental study is carried out on a set of nine photovoltaics modules consisting three modules of each technology i.e. Multi-crystalline (mc-si), Heterojunction with Intrinsic Thin layer (HIT) and Amorphous Silicon (a-si). Various electrical performance data has been collected and characterized for a period of three years in the composite climate of India. The research methodology includes mapping of series resistance, estimation of monthly average effective peak Power (Peff), Performance Ratio (PR) and temperature corrected Performance Ratio (PRT_CORR) has been carried out. The average percentage reduction in the effective peak power (ΔPeff) for the mc-si, a-si and HIT modules were 15.8%, 17.2%, and 7.1% respectively over a period of three years. The monthly average PR for mc-si, a-si and HIT modules were 0.70, 0.82 and 0.83 respectively for the same period. The PR T_CORR over three-year duration for mc-si is 0.77, for a-si is 0.89, and 0.90 for a HIT modules respectively. The annual degradation is 1.5%, 1.6% and 0.39% for mc-si, a-si and HIT modules respectively. The increment in the series resistance has been calculated estimated using the procedure I of the IEC 60,891 Edi 2.0 and the mapping of the series resistance has been done with the matrix of in-plane irradiance and module temperature. Further, the uncertainty calculations of series resistance have been estimated for three different irradiation ranges i.e. 1000 W/m2, 900 W/m2 and 800 W/m2 which is around 4% to ensure the sanctity of measurements and calculations. It has been observed that module degrades faster in hot climatic zones. The interpretation of measured and calculated results, correlation of bus-bar corrosion, and module degradation have been delineated for the composite climate. Finally, it also discusses the usage of the above-proposed methods/tools for optimization of solar cell design parameters at different climatic conditions.

Day-Lighting and Thermal Performance of a Building with a Courtyard in Composite Climate: A Case of Bhopal

Passive Design is important for the current era in the aspect of architectural and environmental friendly view of buildings. It is always considered that the principles of a good passive design suitable for your climate effectively ‘locks in’ thermal comfort, low heating and cooling bills, and reduced greenhouse gas emissions for the life span of buildings. The courtyard is suitable in almost all building typologies in various climatic zones due to its social, environmental and therapeutic potentials. The main objective of this study is to investigate the Central courtyard design of MANIT Energy Centre Bhopal in an aspect of indoor thermal comfort and presence of daylight. The courtyard configurations, courtyard orientation, and natural features like daylight, which is required for Courtyard design were investigated in a courtyard building in MANIT Energy center Bhopal. The methodology of this study involved the developing of a data chart which is based on temperature and illuminance available in four directions of the building, and the statistical description method was used to interpret and analyzed the data. The Results of this study shows that MANIT Energy Center Bhopal central courtyards buildings were designed based on a cautious consideration like orientation, configurations and natural features to enhance their effective daylight availability and passive cooling potentials. MANIT Energy center Bhopal building courtyard study concluded that it is inventively designed but future experimental studies to appraise their thermal performances is required, and optimum performance can be predicted. Therefore, further studies based on simulation are recommended.

Design feasibility of load-bearing masonry building for energy-efficient construction

With increasing urbanisation in developing countries such as India, designing low-cost and energy-efficient housing is an urgent requirement. Adoption of sustainable construction methods and materials assist in reducing the environmental impact and cost of these constructions. This paper compares the design feasibility of a single-storey load-bearing masonry building and a reinforced-concrete-framed structure for energy-efficient constructions. A systematic methodology is applied for residential buildings that come under the composite climate zone. Given energy-efficient design, two different building typologies, one a load-bearing structure with filler slab and the other a conventional reinforced-concrete-framed structure, have been analysed by a computational approach. With due consideration for structural stability, embodied energy, peak cooling load and the cost of construction were evaluated and compared. The load-bearing structure designed with filler slab resulted in saving costs and embodied and operational energy demand by 5%, 32% and 25%, respectively, as compared with the traditional reinforced-concrete-framed structure.

Comparative study of thermal comfort and adaptive actions for modern and traditional multi-storey naturally ventilated hostel buildings during monsoon season in India

The prime objective of the hostel buildings is to provide an adequate thermal environment to the students for their good health and learning performance. However, a few studies have been reported so far in such buildings around the world. This paper reports the findings of a questionnaire based thermal comfort study in six naturally ventilated hostel buildings located in Jalandhar city, lies in composite climate of India, during the monsoon season (August-September 2018). The study was carried out in two newly constructed (aged less than 5 years) and four traditional (aged more than 25 years) multi-storey naturally ventilated (NV) hostel buildings. During the study, a total of 945 completely filled questionnaires from 470 occupants were collected. About 80% and 75% of subjects voted within central three categories of ASHRAE thermal sensation scale in traditional and modern NV hostel buildings, respectively. Results from the probit analysis revealed that 80% of subjects voted within ± 1 TSV when indoor operative temperature ranged between 27.2 and 31 °C. The mean indoor comfort temperature as calculated by Griffiths method is 29.9 °C (sd(±σ) = 2.16). To restore comfort primary adaptive action of occupants was found to be switching on the fans followed by the opening of external doors and windows.

Thermal performance analysis of parallel serpentine flow based photovoltaic/thermal (PV/T) system under composite climate of Malaysia

Photovoltaic (PV) technology suffers from the major drawback of poor energy conversion efficiency that is further worsened by overheating of the module. Hybrid photovoltaic thermal (PV/T) collectors have brought about a notable change in this technology by enabling the extraction of both electricity and heat from the same module, thereby improving the overall efficiency. However, there are some technical challenges with these devices that obstacles their wide-scale application. The major shortcoming of conventional water based PV/T collector is that their operation is limited only in the daytime. To overcome these challenges, novel parallel serpentine pipe flow based PV/T has been designed, developed and studied. The experiments were performed at different volume flow rates viz. 0.5–4 L per minutes (LPM) to optimize the designed and developed PV/T. Maximum thermal efficiency of PV/T system was found to be as 76.58% at 2 LPM. Electrical efficiency of PV and PV/T-only was found to be 9.89% and 10.46% respectively. The maximum exergy efficiency of PV and PV/T system has been found 7.16% and 12.98% (0.5LPM) respectively.

Advancing building bioclimatic design charts for the use of evaporative cooling in the composite climate of India

Building Bio Climatic Design Charts (BBCC) are essential for understanding the thermal conditions prevalent inside occupant spaces and aid in assessing the potential of passive and low-energy cooling strategies like evaporative cooling. An intensive field study carried out in 10 selected office buildings using direct and two stage indirect/direct evaporative cooling systems during the summer season in composite climate of Jaipur city. The respondent perception and preference were collected using transverse survey from 1554 samples spread over a total period of two years, covering, wide age groups and clothing types. This dataset was used to test the accuracy of ASHRAE 55’s thermal comfort zones for the assessment of indoor thermal comfort in surveyed buildings. Study revealed that the subjects in the evaporatively cooled buildings of this region were comfortable at different temperature and humidity levels than those defined in ASHRAE 55 and ISO 7730 standards. This is attributed to the difference in comfort expectations and preferences, as well as the region-specific adaptation of people living in tropical climates. Redefined thermal comfort zones and design polygons for capturing the full potential of evaporative cooling were outlined corresponding to 80% acceptability criteria, based on field measurements and subject’s responses for the indoor airspeed ranges (0-0.5 m/s, 0.5-1 m/s and 1-1.5 m/s).

Performance evaluation of climate responsive buildings in India - Case studies from cooling dominated climate zones

India has a rich tradition of climate responsive architecture, incorporating several variations of passive design strategies that have been layered over time with the cultural, social and environmental context of the immediate geographical region. Designing climate responsive buildings is challenging, requiring an understanding of building physics, as well as the way buildings are designed, constructed and operated in a given cultural context. The process becomes more difficult with the ever-increasing comfort expectations. Unfortunately, it is easier to install air conditioners in a poorly designed building than to design a high-performing building to begin with.This paper is based on a study to evaluate the thermal performance of climate responsive buildings. We studied six modern institutional and office buildings in warm-humid, hot-dry and composite climate zones. Collectively, they incorporated a range of passive and hybrid design strategies, including various shading devices, courtyards, solar chimneys, cavity walls, various configurations of thermal mass, day and night-time ventilation, and evaporative cooling. We monitored each building for a period of one year and assessed their performance in terms of the behaviour of selected components, their overall response to the prevailing outdoor conditions. In addition to the measured variables, we compared performance using temperature gradients overlay on wall sections, heat maps and linear regression analysis to understand the relationship between the outdoor and indoor conditions to determine the nature of “climate responsiveness” of each building.

Influence of building design and control parameters on the potential of mixed-mode buildings in India

The potential of mixed-mode office buildings with varying design and control parameters is examined by using an uncertainty analysis in the three climate zones of India. The analysis is in terms of cooling energy consumption, thermal comfort conditions, and natural ventilation hours. Furthermore, influential parameters are identified using sensitivity analysis. In this study, opening the windows enables natural ventilation. Night-time ventilation through the windows is not enabled because these are mostly closed at night. A maximum natural ventilation of 10% of the total building occupancy hours are observed in warm and humid, and hot and dry climates; however, they are slightly higher in the composite climate. A further increase in the number of natural ventilation hours leads to an increase in the occupancy hours outside the Indian Model for Adaptive Comfort model for mixed-mode buildings with at least 90% of occupants are satisfied. There are no occupancy hours outside of 80% of occupants are satisfied. The choice of thermal comfort band is crucial for determining the potential of mixed-mode buildings. The cooling setpoint temperature, building size, window solar heat gain coefficient, and surface properties of exterior surfaces are identified as the more influential parameters than the thermophysical properties of building envelope constructions. Although the building envelope which is in compliance with the Energy Efficient Building Code of India increases energy efficiency during air-conditioning periods, whether it reduces natural ventilation hours, because of overheating during such period remains to be determined.

Solar radiation on south‐facing inclined surfaces under different climatic zones in India

In this work, solar radiation availability has been estimated for south‐facing inclined surfaces in India. Five different climatic zones prescribed by Energy Conservation Building Code (ECBC) for India have been considered. A comparison of optimum tilt angles and corresponding incident solar radiation for representative locations under different climatic zones, that is, Srinagar (cold), Delhi (composite), Jodhpur (hot and dry), Mumbai (warm and humid), and Bangalore (Temperate) has been established. Gains in the availability of incident solar radiation in comparison with a horizontal surface observed for Jodhpur and Bangalore were found to be maximum (15.77%) and minimum (7.57%), respectively, on monthly optimum tilt angle. A loss of 5.74% for cold climate, 7.49% for composite climate, 6.16% for hot and dry climate, 4.30% for warm and humid climate, and 4.39% for temperate climate were estimated with surface tilted at annual optimum tilt in comparison with a surface at monthly optimum tilt angle. A linear relationship was observed between annual optimum tilt angles and locations latitude as βopt(annual) = 0.671 ϕ + 9.087 with R2 = 0.9984. It was concluded that climatic conditions can considerably affect the availability of incident solar radiation under different climatic zones. ‘ 2018 American Institute of Chemical Engineers Environ Prog, 38:e13050, 2019

GIS based quantification and mapping of climate change vulnerability hotspots in Addis Ababa

BackgroundUnlike the studies undertaken on agricultural and hydrological sectors, focused climate change vulnerability researches in urban centers in Ethiopia is not widely available and of recent history. However, as many signals of climate change vulnerability started to happen in urban centers as well, it is inevitable to analyze, quantify, map, prioritize and be prepared for adaptation measures. This study is therefore, tried to assess, quantify and map climate change vulnerability in Addis Ababa, Ethiopia, by integrating two climate change vulnerability assessment models, namely, the Sullivan and Meigh’s Model of composite climate change vulnerability index and the IPCC’s approach of vulnerability assessment which comprises exposure, sensitivity and adaptive capacity. Fifteen sub-components of vulnerability indicators were identified in ten sub-cities (Addis Ketema, Arada, Akaki-Kality, Bole, Gulelle, Kirkos, Kolfe-Keraniyo, Lideta, Nifasilk-Lafto and Yeka) of Addis Ababa. Due to the scale, degree, amount and unit of measurement for the selected indicators varied, their values were normalized to a number which ranges between 0 and 1, indicating as the values increased to 1, vulnerability to climate change increases. The study uses Iyengar and Sudarshan’s unequal weighting system, to assign a weight to all indicators. The results were mapped using ArcGIS 10.2 package.ResultsThe results indicated that the ten sub-cities in Addis Ababa were found in different levels of vulnerability to climate change. The exposure and sensitivity were highest for Addis Ketema, Arada, and Lideta which are found in central parts of the city, with a normalization index value greater than 0.5. The adaptive capacity index is the highest in Gulelle, Bole, and Arada sub-cities. These sub-cities have better quality houses, well-planned districts, good infrastructural facilities and good coverage of green areas compared to others. The overall climate change vulnerability was the highest (normalized index > 0.5) in Arada, Addis Ketema and Lideta, due to the adaptation capacity is the lowest compared to other sub-cities.ConclusionAddis Ababa is vulnerable to climate change impacts and the degree of vulnerability is underpinned by the interaction of multiple factors mainly adaptive capacities of sub-cities, location based characteristics and changes in climatic parameters. These present a need to strengthen mitigation and adaptation activities and prioritize sub cities for intervention based on the degree of vulnerability. It is also understood that the Sullivan and Meigh’s Model and IPCC’s approach for climate change analyses, could be used simultaneously for preparing vulnerability index per different geographical locations.

Thermal performance and comfort potential estimation in low-rise high thermal mass naturally ventilated office buildings in India: An experimental study

This study assesses the applicability of thermal mass as a passive design strategy in naturally ventilated office spaces in composite climate of India. The research is an experimental study of two high thermal mass office buildings with different thermal properties, operated under natural ventilation mode for the year 2015–2016 in Jaipur city, India. The part of field measurement data is used to generate indoor-outdoor correlations and validated on remaining data to predict indoor temperatures inside high mass offices buildings. In addition, developed correlations showed a good correlation coefficient (R2 ≥ 0.92) when applied to predict indoor temperatures of similar constructed passive buildings. Developed correlations are further used to predict the potential of using high thermal mass in avoiding thermal discomfort during summer and winter season of a year. To show the contrast composite climate zone specific adaptive comfort zone i.e. ACZ and existing ASHRAE Standard 55-2013 comfort zone has been considered. Analysis of results showed that an additional 40% and 98% of the total thermal discomfort time can be avoided with the use of thermal mass in building envelope for the summer and winter season, respectively. Moreover, the percentage of time thermal comfort achieved as calculated by using ASHRAE Standard 55-2013 comfort zone was far less as compared to composite climate specific ACZ.

Development of a composite climate change vulnerability index for small craft harbours

ABSTRACTCoastal areas around the world are threatened by an accelerated sea level rise (SLR), storm surges and coastal flooding related to climate change. These threats, together with the land use pattern of coastal areas, could create a dangerous mix for coastal communities and could result in major socio-economic and environmental consequences. Apart from human settlements, seaports are likely to be most vulnerable to climate change because they are located at areas exposed to SLR and storm surges or at mouths of rivers susceptible to flooding. To remain efficient and resilient, seaports must anticipate the impacts of climate change and proactively prepare for SLR, increased flooding, and more frequent extreme storm events. This paper presents the analytical and empirical aspects of an integrated vulnerability index (VI) for small raft harbours based on the methodology of the IPCC for coastal vulnerability assessment. Six corresponding steps are adopted to assess the fishing ports VI (VIP-F) considering geophysical and socio-economic parameters. The proposed index is applied to 47 fishing boats and small commercial harbours of Lesvos, Greece. The proposed methodology can be adapted for assessing the vulnerability of major ports.

Evaluation of comfort preferences and insights into behavioural adaptation of students in naturally ventilated classrooms in a tropical country, India

A transverse questionnaire based thermal comfort field study was conducted in 30 naturally ventilated university classrooms during peak summer months in composite climate of India. A detailed statistical analysis was carried out on 900 thermal comfort surveys database containing information about sensation and preference for different indoor environmental variables. Neutral temperature predicted through linear regression method varied more than 3 °C for different surveyed buildings. More than 90% comfortable votes (±1 votes) of the present database do fit within adaptive comfort boundaries for this climatic zone of India. Additionally, the study estimated a preferred temperature of 26.4 °C using probit analysis. During the field study, personal and global adaptive actions (adaptive actions that tend to modify the indoor environment of classroom) of students during regular classes were recorded and analyzed. Analysis concluded that students preferred high air speed ranges for restoring comfort either by opening windows and doors as or by operating ceiling fans. Logistic regression model predicts more than 80% ceiling fan usage at indoor air temperature 29 °C.

Performance Prediction and Assessment of Energy Conservation Potential for a Light Pipe System in Indian Composite Climate of New Delhi

Light pipes are popularly used for transporting outdoor sunlight into deep spaces of the building, and hence, use of artificial lighting could be substantially reduced. Performance prediction of a light pipe is an essential step before its use in buildings, so that energy saving potential of the light pipe could be quantified. This paper deals with experimental validation of three existing semi-empirical models for light pipes with different aspect ratios, installed on a windowless test room, at IIT Delhi, New Delhi. Two new semi-empirical models based on the existing correlations are developed. The new model found to perform better with mean bias error (MBE) and root-mean-squared error (MSE) of 0.076 and 0.01, respectively. The better performing new model is used for the evaluation of hourly internal illuminance by the light pipe in a typical meteorological year (TMY) in New Delhi. From hourly internal illuminance in a typical meteorological year, the energy saving potential and CO2 mitigation potential of light pipe system for the test room are evaluated. Monthly average energy saving potentials of the light pipe-fluorescent tube light system are found to be 50% for continuous dimming control and 38% for three-step on–off control. Results show that the light pipe-fluorescent tube light system, with different lighting controls, could reduce CO2 emissions to 15–50%.

Calibrated simulation analysis for integration of evaporative cooling and radiant cooling system for different Indian climatic zones

Radiant cooling system (RCS) has proven to be an energy efficient system for meeting a building's cooling requirements. RCS is energy efficient and provides better thermal comfort compared to conventional all-air heating ventilation air conditioning (HVAC) system. To further improve the efficiency of RCS, a parallel evaporative cooling system (cooling tower) is coupled with RCS and analyzed for different climatic condition using calibrated model. A statistical analysis of weather files (based on wet bulb temperature), was used to identify the availability of useful water for cooling tower integration with RCS. A comprehensive simulation feasibility study of the application of cooling tower in RCS was performed for different cities to cover every climatic zones of India. It was found that in summer, the wet bulb temperature (WBT) of different climatic zones, except warm-humid, is suitable for the integration of cooling tower with RCS. An experimental setup was designed and developed for integration of parallel chiller and cooling tower with panel-based RCS for cooling and a dedicated outdoor air system (DOAS) for dehumidification and ventilation. Experiments were conducted for chiller and cooling tower operated RCS in Composite climate of Jaipur, Rajasthan, India. Building Energy Models (BEM) were developed for both the chiller-operated RCS and cooling tower-operated RCS in EnergyPlus and calibrated with the measured data. Using the calibrated models, performance of the system was analyzed for different climatic zones of India. A chiller-operated RCS was considered as a baseline to compare the annual energy saving potential and monthly performance of the cooling tower integrated RCS. In the cooling tower–operated RCS, a total annual savings of 7% in hot and dry climates, 11% in composite climates and 20% in temperate climates was achieved compared to the chiller-operated RCS.

Thermal comfort study in naturally ventilated school classrooms in composite climate of India

A field study was carried out during monsoon and winter seasons of 2015–16 to investigate the thermal environment and thermal comfort in naturally ventilated (NV) indoor environment of classrooms of a Government residential school located in composite climatic zone of Ambala, India. A total of 640 responses from 130 students in the age group between 10 and 18 years belonging to rural background were collected. An indoor operative temperature of 27.1°C was recorded as neutral temperature. The slope of the regression line plotted between thermal sensation and indoor operative temperature was found to be 0.056/°C which varies considerably from earlier similar studies on classrooms across tropics. It has been found that the students feel comfortable within operative temperature range of 15.3–33.7 °C for 80% acceptability. This range exceeds beyond the comfort temperature range as specified by Indian and international standards for adult population. The results show that the heat tolerance of the students is quite high. In India, till so far there are no thermal comfort standards for school classrooms in any of the climatic zones. The findings of this study should provide guidelines for India specific thermal comfort standards for schools for the efficient use of energy.

Atmospheric and Surface Climate Associated With 1986–2013 Wildfires in North America

AbstractWe analyze climate simulations conducted with the RegCM3 regional climate model on 50‐ and 15‐km model grids to diagnose the dependence of wildfire incidence and area burned variations on monthly climate long‐term means and anomalies over North America for the period 1986–2013. We created a new wildfire database by merging the Fire Program Analysis Fire‐Occurrence Database, the National Interagency Fire Center Fire History Data, and the Canadian National Fire Database. The database includes 2,083,865 daily fire starts that burned a total of 1.25 × 108 ha in North America. We derive long‐term climatologies, standardized gamma indices, and composite climate anomalies of atmospheric circulation (500‐hPa height and wind) and various surface fields (e.g., solar radiation, soil moisture, vapor pressure deficit, and latent and sensible heat fluxes) to illustrate the climatology of burned area. The immediate and lagged monthly atmospheric circulation and surface climate anomalies differentiate high‐ and low‐fire years and the role of El Niño–Southern Oscillation in wildfire occurrence. Our approach demonstrates the association of the seasonal cycles of wildfire and climate and the strong role of climatic variability in modulating the seasonal cycle as a control of wildfire on monthly time scales.

Factors Contributing to the Performance of Green Roofs and their Impact on Cooling Loads for a Composite Climate, Case Study: New Delhi

Factors Contributing to the Performance of Green Roofs and their Impact on Cooling Loads for a Composite Climate, Case Study: New Delhi

Non-destructive in-situ performance monitoring of high-efficiency SPV modules using infrared thermography in composite climate of India

Non-destructive in-situ performance monitoring of high-efficiency SPV modules using infrared thermography in composite climate of India

Sulfur deposition changes under sulfate geoengineering conditions: quasi-biennial oscillation effects on the transport and lifetime of stratospheric aerosols

Abstract. Sustained injection of sulfur dioxide (SO2) in the tropical lower stratosphere has been proposed as a climate engineering technique for the coming decades. Among several possible environmental side effects, the increase in sulfur deposition deserves additional investigation. In this study we present results from a composition–climate coupled model (University of L'Aquila Composition-Chemistry Model, ULAQ-CCM) and a chemistry-transport model (Goddard Earth Observing System Chemistry-Transport Model, GEOS-Chem), assuming a sustained lower-stratospheric equatorial injection of 8 Tg SO2 yr−1. Total S deposition is found to globally increase by 5.2 % when sulfate geoengineering is deployed, with a clear interhemispheric asymmetry (+3.8 and +10.3 % in the Northern Hemisphere (NH) and the Southern Hemisphere (SH), due to +2.2 and +1.8 Tg S yr−1, respectively). The two models show good consistency, both globally and on a regional scale under background and geoengineering conditions, except for S-deposition changes over Africa and the Arctic. The consistency exists with regard to time-averaged values but also with regard to monthly and interannual deposition changes. The latter is driven essentially by the variability in stratospheric large-scale transport associated with the quasi-biennial oscillation (QBO). Using an externally nudged QBO, it is shown how a zonal wind E shear favors aerosol confinement in the tropical pipe and a significant increase in their effective radius (+13 % with respect to W shear conditions). The net result is an increase in the downward cross-tropopause S flux over the tropics with dominant E shear conditions with respect to W shear periods (+0.61 Tg S yr−1, +42 %, mostly due to enhanced aerosol gravitational settling) and a decrease over the extratropics (−0.86 Tg S yr−1, −35 %, mostly due to decreased large-scale stratosphere–troposphere exchange of geoengineering sulfate). This translates into S-deposition changes that are significantly different under opposite QBO wind shears, with an E–W anomaly of +0.32 in the tropics and −0.67 Tg S yr−1 in the extratropics. Most online QBO schemes predict a significant change in the zonal wind periodicity, up to a blocked E shear condition for large enough injections, so that our results indicate an upper limit for the tropical increase in S deposition of 16.5 % relative to average conditions of unperturbed QBO periodicity and a correspondent extratropical S deposition decrease of 16 %.