Passive Solar Techniques Research Articles

Mathematical Modeling and Validation of Solar-Induced Ventilation System for Vehicle Cabin Cooling in Hot Parking Conditions

Exposure to direct sunlight raises interior temperatures in vehicle cabins, risking heat-related illnesses. Solar passive techniques mitigate this issue, especially during hot parking conditions. However, a comprehensive mathematical model encompassing both solar chimney and vehicle cabin is lacking. This study develops a novel mathematical model to predict temperature distribution and airflow rate, enhancing system performance evaluation. The system comprises a solar air collector with an adjustable arm mounted on the vehicle's roof. The model was validated theoretically and experimentally. The experimental work is conducted with the physical model with an air gap of 0.1 m, 0.77 m width, and a 1.12 m collector length under outdoor conditions. Results indicated a gradual increase in temperatures of the glass cover, air in the collector channel, absorber, and mass airflow rate with solar radiation intensity, significantly influencing system performance. The high value of R2 and the consistency of the model's results with theoretical and experimental outcomes justified the validity and accuracy of the proposed model, exhibiting a deviation percentage of less than 10%. The developed model can be utilized to study influential parameters for optimizing the proposed strategy's performance and components, yielding comparable results to experimental data. Additionally, it provides researchers and car makers with a broader perspective and a range of options for further improvement in weight, size, cost, and aerodynamic of the vehicle.

Sustainability of traditional building practices in Nigeria: The case of Igala traditional architecture

Nigeria's diverse ethnic landscape is marked by distinct traditional building practices, each representing a unique cultural identity. This study delves into the architectural heritage of the Igala people of North Central Nigeria, shedding light on their sustainable building practice. Despite its profound cultural and historical significance, the Igala traditional architecture, like many others in Nigeria, faces challenges due to modernization. This trend is pervasive across Nigeria, where contemporary buildings often disregard indigenous socio-cultural, environmental, and climatic considerations in their design and construction. Consequently, modern buildings in Nigeria tend to be costly and incompatible with the local culture, environment and climate. This study explores the imperatives and values of Igala traditional housing pattern, aiming to enhance the sustainability of contemporary building practices in Nigeria. Employing a narrative approach, the study utilized archival/historical research, field surveys, and interviews with local building professionals, indigenous elders, and environmental experts to explore the Igala traditional building practice. Thematic content and descriptive analysis were used to interpret the gathered data. The study revealed intrinsic features of Igala traditional housing pattern, including the courtyard system, hierarchical spatial arrangement, organic expansion, food storage facilities and the integration of socio-economic and socio-cultural spaces. These features exemplify sustainability through values such as security, privacy, communal living, cultural identity, energy efficiency, resource efficiency, passive solar techniques and environmental conservation. The research emphasized the critical importance of these identified features and values, not only for preserving cultural heritage but also for guiding sustainable contemporary architectural practices in Nigeria.

Passive Solar Technology and its Techniques

Passive solar technique is which converts the natural energy into usable energy resources. The passive solar energy is the sunlight that is been got directly or indirectly are been converted to heating or cooling purpose. This process is been effectively used all over the world for the future development. As the usage such as the solar technologies and other innovative techniques this does not involve in most of the mechanical process. Solar energy is mostly environmentally friendly and eco friendly that are blending with day to day life. The light and heat that are been got naturally are used to provide electricity that can be used in building s interior and exterior purpose. The most possible ways that the passive solar technique is that the maximum use of the windows and doors, shading devices, louvers and angular roofing are the methods that can be used for the passive solar energy techniques. The next method passive solar heating is also an technique that makes or traps the heat and saves the heat in any part of building based on the required material. This allows heat that is needed at required times during different weather conditions the passive solar technique plays an important role during different climatic conditions. During the summer season it prevents the direct heat entering the building and can be reduced based on growth of the plant such as shrubs and creeper plants. During the winter season it emits the heat to the entire building such as the material been used such as concrete, thermal mass material ,stone slabs, these have more emitting power and makes the entire place more warm and heat. Most of the application techniques and methods will be studied later with following research ideas.

Experimental studies on the energy performance of a novel wavy-shape Trombe wall

Trombe wall is widely used as a passive solar technique to reduce energy consumption in buildings. Numerous studies have been carried out on improving the conventional Trombe wall, but few of them have focused on the impact of its shape on energy performance. In this research, the energy performance of the novel wavy-shape Trombe wall has been investigated. The experimental results showed that the novel wavy-shape Trombe wall model with an intersection angle of 90° or 120° has significantly improved the air velocity, surface and airflow temperatures, resulting in better overall performance. The heat flux of the wavy-shape Trombe wall model with an intersection angle of 90° is 24% and 68% higher than that of the flat model with the incidence angles of 40° and 60° respectively. The heat flux of the wavy-shape Trombe wall model with an intersection angle of 120° is 7%, 8%, and 4% higher than that of the flat model with the incidence angles of 20°, 40°, and 60° respectively. The results showed that a wavy-shape Trombe wall with a proper intersection angle, within a considerable percentage of daytime, has a much better energy performance than a traditional Trombe wall.

Persistance et renouvellement des mentalités techniques : le cas de l’opposition entre les techniques solaires actives et passives en architecture

L’histoire des énergies dites alternatives révèle de profondes divergences. Notre article se concentre sur un débat relatif aux techniques de captage, de stockage et de distribution de l’énergie solaire en vue du chauffage domestique, qui a été particulièrement animé durant les années 1970 et 1980 en France comme aux États-Unis, et qui a opposé les partisans des techniques solaires dites « actives » et « passives ». En étudiant la genèse de cette opposition à partir de documents de cette période, nous souhaitons montrer à l’aide de la philosophie des techniques qu’elle illustre une opposition entre deux mentalités techniques divergentes, qui traduit deux approches différentes de cette énergie alternative.

Analysis of Indian Traditional Buildings using Passive Cooling through Natural Ventilation Techniques

Abstract: There is a rapid increase in the use of active cooling strategies for ventilation and air circulation in the recent scenario, and hence an urge of climate-responsive buildings is a need of today. Taking the advantage of local climate and designing buildings that decrease energy use can be achieved by implementing passive cooling strategies in a building. The present study focuses on how various solar passive techniques have helped in designing climate-responsive structures in the past and how its implementation can enhance the structure in modern construction techniques. By analysing structures from the past and studying the science behind them, the passive cooling effect and its development in design implementation can be examined. The paper concludes by having incited on how solar passive strategies can help to create a flexible building, responding to climatic effects and its evolution over a period of time. Keywords: Climate responsive, Hot-dry climate, passive cooling, Traditional buildings

A Conceptual Review of the Potential of Cool Roofs as an Effective Passive Solar Technique: Elaboration of Benefits and Drawbacks

Cool roofs, as feasible and efficient passive solar technique that reduces building energy requirements for cooling and improves indoor thermal comfort conditions, have received considerable attention in recent years and as a result, a number of concepts, methods, and experiences have been developed during the related research. Although some studies have been conducted on this subject in the form of review articles, taking into consideration the large number of publications, there is still a call for some review papers dealing with the potential of cool roofs and providing a thorough report on their energy performance and a detailed summary of their pros and cons on the basis of the relevant studies. On this account, this study contributes a systematic review of the issued paper in Scopus and Web of Science regarding the cool roof technologies to recognize the advantages and challenges of cool roofs in practice and its future trends. In addition, detailed summary of advantages and drawbacks of this passive solar measure has been developed, as itemized factors corresponded to the codified references. A total of 90 published reports were analyzed, declaring that a cool roof is an efficient approach for generating clean energy on the building scale. This article induces an overall view of the advantages and restrictions of the cool roof throughout the world. Conclusions give a valuable reference for improving the cool roof design for their more widespread use in the building industry.

Passive air cooling system and solar water heater with Phase Change Material for low energy buildings in hot arid climate

Solar energy is considered alternative crucial to fulfilling the increasing of energy requirements. Passive cooling systems are considered alternatives to mechanical ventilation systems. In this work, a highlight for a solar chimney with water heater and Phase Change Material is applied as a passive solar technique for cooling building integrated with short wind tower for low energy building in the hot arid climate. This paper aims to investigate the performance of new passive air condition system with the solar chimney and solar water heater as a full system for cooling air and heating water to be applied during day and night time based on the improvement of the solar chimney in Assiut climate, Egypt. Measurements, for air temperatures and surface temperature of the aluminium and air velocity inside the chimney, water temperature and room temperature were conducted with different solar radiations to evaluate the panel performance and room thermal comfort. The findings show a minimum airflow rate in the chimney after sunset equal to 0.69 kg/s to provide fresh cold air during a hot day with a water temperature equal 58 °C and 40 °C during 2 pm and after sunset respectively. Also, integration of solar chimney and PCM with cooling wind tower achieves a significant reduction for room air temperature between 8 and 4 k during day and night time respectively and the condition within the comfort range of Predicted Mean Vote (PMV) especially night time. The results provided information to integrate this new low energy compact passive air cooling and water heating system for the housing projects of the upper floor in a hot arid climate in Egypt.

Simulation Study of Trombe Wall for Passive Solar Technique of buildings in Egypt

The studies aimed to evaluate a Trombe wall, a solar wall, which is a critical component of passive solar strategies in energy usage. It is a very compact wall and can be south-facing or north-facing, which is painted black and made of exclusive material that absorbs a lot of heat. The main advantage of the Trombe wall is that they are often easily built from locally obtainable materials, very dependable, and having less repair, maintenance, and operation costs. In this study, a BASECASE model were simulate with “Design Builder” software based on “Energy Plus” with the passive solar technique of Trombe wall in Egypt of a model of residential building with two façade alternative base case. The research has shown that Trombe wall has the possibility of providing acceptable internal thermal comfort through “Mixed-Mode” ventilation strategy in hot climate, this is important in determining the possibility of Trombe wall in incorporating “Mixed-Mode” ventilation reducing energy usage in cooling demands. The conclusion of this research that Trombe walls can reduce the cooling load by 75% compared to the base case with annual energy savings.

Heat collection in an attached sunspace

The attached sunspaces are classic bioclimatic systems. Normally, they are used as solar passive techniques in buildings. However, it has been suggested that they could also be used as active systems in order to collect solar energy and harness it in the heating, ventilation and air conditioning (HVAC) equipment. This paper analyses the sunspace built during the ARFRISOL project, which has a validated simulation tool of its thermal behaviour, developed in a previous research. In this paper, this tool is applied to study the possibility of the energy collection. Although this energy is not enough to be used as direct heating system, it can pre-heat the air before entering the HVAC equipment. Two configurations have been studied: collecting the energy during the whole day or only at night to take advantage of the sunspace thermal inertia. Also, the results obtained with these configurations have been compared with the sunspace used in passive mode. For this analysis, several characteristic days with summer and winter climatic conditions have been considered. Finally, an economic evaluation of this innovative system –a solar active sunspace- is performed taking into account the results of the different configurations.

Thermal Comfort Studies on Houses in Hot Arid Climates

The traditional houses in Ghardaia City in Algeria had been built using traditional construction materials and passive solar design (PSD) strategies for the hot desert climate. These thousand-year-old houses are still standing and conditioning the harsh desert climate while maintaining indoor thermal comfort for its occupants. Of late, two trends of modern housing and construction were observed to have evolved in Ghardaia. Firstly, were the modern houses (Mod.H) following the international style and secondly, the eco-friendly houses (Eco.H), modern houses but utilising passive solar design. The Mod.H was observed to implement some of the traditional features but using the modern construction material. Meanwhile, the Eco.H modified the characteristics of the traditional construction and materials carefully in a modern context. Analyses were conducted to investigate the thermal performances of the three house designs. The intention was to ascertain the best construction that can achieve and maintain thermal comfort according to ANSI-ASHRAE 2014, in this harsh desert climate. Based on the Trad.H model, comfort data the two more modern houses were also monitored. Data collection was carried out in July, which was one of the hottest months. The study indicated that passive solar techniques employed in the Trad.H were able to maintain the comfortable indoor environment for the occupants without any mechanical aid. The indoor temperature of the Eco.H was 3 to 9 °C higher, and the Mod.H difference was 5 to 9°C above the thermal comfort zone. The study ascertained that designs of buildings with traditional construction and material played a significant role in moderating the indoor environment when the outdoor climate of the Algerian desert was unbearable. Inadvertently, energy for cooling was saved creating a significant impact not only on the economy both at the national and global level, but on the environmental scale as well.

Research on the Thermal Environment of Northeast China's Rural Residences

Rural residential energy consumption accounts for 46.6% of total building-related energy consumption of China. In Northeast China, energy consumption for space heating represents a significant proportion of total rural residential energy consumption and has reached 100 million tce (tons of standard coal equivalent), or more than 60% of total household energy consumption. In terms of energy consumption per square meter of gross floor area, rural residential energy consumption for heating is more than that of cities (20kgce/m2). However, the average indoor temperature of most rural residence is below 10°C, much less than that in cities (18°C). Hence, it is an important task for Chinese energy saving and emission reduction to reduce rural residential energy consumption, while enhancing indoor thermal comfort at the same time.Restricted by local technology and low economic level, rural residences currently have poor thermal insulation resulting in severe heat loss. This paper reports on research aimed at developing design strategies for improving thermal insulation properties of rural residences with appropriate technology. A field survey was conducted in six counties in severe cold areas of Northeast China, addressing the aspects of indoor and outdoor temperature, humidity, internal and external surface temperature of building envelop enclosure, and so on.The survey data show the following:1. Modern (after 2000) brick-cement rural residences perform much better than the traditional adobe clay houses and Tatou houses (a regional type of rural residence in Northeast China – see figure A) in overall thermal performance and indoor thermal comfort;2. Among the traditional residential house types, adobe clay houses have better heat stability and thermal storage capacity than Tatou houses;3. Applying an internal or external thermal insulation layer can greatly improve rural residential thermal insulation properties, and is an economical and efficient solution in rural areas;4. In terms of roofing materials, tiled roofs show much better thermal insulation properties than thatch roofs;5. Adopting passive solar techniques can form a transition space (greenhouse) against frigid temperatures, resulting in interior temperatures 5.91°C higher than the outside surroundings. It is evident that local passive solar room design offers significant heat preservation effects and lower cost ($12/m2), embodies the ecological wisdom of rural residents, and is therefore important to popularize.The above experimental results can provide guidance in energy conservation design for both self-built residences and rural residences designed by architects. In addition, the results can also provide experimental data for energy-saving studies for rural residences in China.

Design and Analysis of Solar Passive Architecture for Thermal Comfort of Residential Buildings in Warm-Humid Climate of Thanjavur Region

Objectives: To design and construct a contemporary residential building in warm and humid climate of Thanjavur with solar passive architecture concepts that can make the building thermally comfortable like traditional buildings. Methods/ Analysis: Solar passive architecture concepts and principles are used in traditional buildings worldwide. Thermal performances of such traditional buildings are well within the comfort range as prescribed by thermal comfort standards. But in most of the contemporary buildings, the indoor environmental conditions and thermal comfort are unsatisfactory due to improper design. Hence an attempt has been made to design and construct a contemporary residential building with solar passive designs. Thermal performance analysis is carried out during summer in the designed building and is compared with another contemporary house. Findings: The study on designed solar passive house indicates that improved performance can be achieved by combining the lessons learnt from traditional buildings by incorporating solar passive techniques that can bring indoor temperatures down enough for comfortable indoor environment to the occupants. It is observed that the temperature of the designed solar passive building is 2oC to 3oC cooler in summer in comparison with the contemporary building. It is evident from the study that design of building plays a major role to save energy which in turn gives an impact on national and global economy. These design findings can be applied further to contemporary residences in any context with reference to its local climate. Novelty/Improvement: Ten solar passive architecture strategies have been incorporated in the designed building which include orientation and planning, courtyard design, light coloured painting, white roofing tiles, shading elements, solar chimney and sky light, cross ventilation, landscaping, roof level ventilators and high ceiling roof.

Hybrid PV/T water solar collector for net zero energy building and fresh water production: A theoretical approach

The purpose of this work is to study the possibility of obtaining a net zero energy building and producing fresh water via a solar still by using a hybrid PV/T water solar collector. A solar prototype built in the city of Boussaâda is studied under the climate of Ouargla city to show the importance of the use of passive solar architecture. The results highlight the importance of using passive solar techniques to reduce heating energy needs. Energy savings are realized with passive techniques even before the use of active solar systems. It is possible to cover the energy requirements with the use of hybrid PV/T water solar collectors. High solar thermal fractions for domestic hot water are achieved during the year. Solar electricity produced is high and can cover the annual needs of domestic hot water, air conditioning and heating, lighting and household equipment of the prototype. A part of the difference in area between that used to cover the thermal requirements of domestic hot water and the total area of the PV/T collectors is used for supplying a solar still. An increase in the annual production of 2.97 times is obtained compared to passive solar still.

Development and analysis of advanced inorganic coatings for buildings and urban structures

In recent years a steadily increasing interest has been noticed, concerning the development of advanced materials for both buildings and the urban environment. The aim of the present work is to examine the performance of inorganic coatings as a passive solar technique that contributes to buildings’ energy efficiency. A number of inorganic coatings are developed. The materials used for the coatings’ developed are characterized using XRD and DTA to verify their composition. Their optical properties, i.e. the solar reflectance and infrared emittance are then measured while the samples were also exposed to the outdoor environment for surface temperature measurements. Finally the energy efficiency of the specific coatings are evaluated in an insulated and non-insulated building using ESP-r modelling tool.

Portuguese vernacular architecture: the contribution of vernacular materials and design approaches for sustainable construction

Vernacular architecture is characterized by a type of formal expression, which has been developed in response to a number of factors – geographic, climatic and economic – characterizing the local area or region. Despite the fact that Portugal is a small country, there are many different architectural approaches and a range of techniques have been employed in different regions to mitigate the effects of climate. These vernacular approaches have the potential for further development and could be adapted in response to contemporary needs. In this paper, a range of different passive solar techniques used in Portuguese vernacular architecture to provide comfort is presented. The specific focus is on the effectiveness of passive cooling strategies (namely, high thermal inertia, use of light colours and courtyards), and the findings of a case study in which the thermal performance during the summer of a vernacular residential building located in the south of Portugal are presented.

Design and performance of a novel innovative roofing system for tropical landed houses

An innovative roofing system (IRS) is designed to deliver an abundant and uniform amount of cool natural light from the roof with reduced heat gain effect for tropical residential buildings (3m height) in Malaysia. Studies revealed that several passive and active solar techniques can be integrated to form a roofing system to separate solar heat from useful natural light at the attic zone before heat reaches the occupied space. The IRS design is specified and proposed by using glazing technology (polycarbonate), pigment technique (reflective and radiative), as well as ventilation process (hybrid turbine ventilator) applied at the attic zone to represent a new model of sustainable roofing design. The aim of this research is to demonstrate the effectiveness of the design concept without the need for any chemical, complex, or expensive solar design techniques. The methodology was conducted on a series of field studies in a standard room model at Universiti Sains Malaysia. Three different roofing systems are investigated to identify the IRS performance in both dark and daylight conditions to determine the effect of natural light on the indoor environment. The outcomes of the design show that the IRS was able to reduce the indoor air temperature compared with conventional roofing system by approximately 2.1°C under daylight condition. Results showed that the difference in the IRS (daylight–dark) condition was 0.31°C compared to that in the conventional roofing system at 0.8°C. Furthermore, the level of mean radiant temperature compared with indoor temperature under daylight condition was 2.61°C for the IRS, whereas 4.05°C for conventional roof. Moreover, the IRS successfully delivered an acceptable range of natural light below 2000 lux (Green Building Index) at daytime with a minimum level of 86% compared with 78% for conventional roofing design. As a result, these findings indicated that the IRS with light materials and without any insulation can separate solar heat from useful natural light under the climatic conditions in Malaysia. The system provides a new design paradigm based on the requirements of the Malaysian Green Building Index.

Development and analysis of mineral based coatings for buildings and urban structures

Commonly used materials in the construction of the building façades located in warm climates, often entrap a great amount of heat from the incoming solar radiation, leading to a respective thermal increase in the interior. The aim of the present study is to examine mineral-based coatings as a passive solar technique that contributes to buildings’ energy efficiency. A series of mineral based samples are developed and tested. Their thermal performance is estimated by infrared thermography and surface temperature measurements. Their optical properties are also measured while the energy efficiency is quantified using simulation techniques. The results revealed that renders based on hydraulic and/or hydrated lime with additions of calcium carbonate powder, as well as mineral paints comprised either of lime wash or silicate minerals can behave as cool coatings and contribute to a significant reduction of the cooling demand in warm climates.

Integrating Passive Cooling and Solar Techniques into the Existing Building in South China

This paper draws upon passive cooling and passive solar techniques to integrate them into a common multi-purpose building in South China so as to optimize the indoor thermal environment and reduce building energy consumption. Meanwhile, it also discusses how to combine architecture design and sustainable techniques reasonably. In order to prove that these sustainable design options are effective, CFD, Ecotect and Solpass software should be used to simulate or calculate the heating and cooling loads, discomfort hours for both of the existing and advanced building. Though comparison it is obviously that the indoor discomfort hours decrease by nearly one third by passive cooling system, while passive solar techniques can reduce 25% annual heating loads.

Solar passive techniques in the vernacular buildings of coastal regions in Nagapattinam, TamilNadu-India – a qualitative and quantitative analysis

Bioclimatic concepts in vernacular architecture was developed and used through the centuries by many civilizations across the world. This study is carried out on the vernacular architecture of coastal regions. The vernacular architecture in the coastal belts of Nagapatinam is known for its use of natural and passive methods so as to create a comfortable indoor environment. However, so far, it has not been proved by a detailed quantitative evaluation method. The authors have conducted the qualitative and quantitative analysis to investigate the indoor environmental condition of a vernacular residential building in coastal region of Nagapatinam. The quantitative analysis has been done by continuously monitoring the indoor and outdoor thermal and environmental conditions using a custom made instrument called “Mini metrological Station known as Architectural Evaluation System”. The results of this study research shows that the solar passive techniques used in these vernacular residential buildings in coastal region provides comfortable thermal indoor environment irrespective of the outdoor climatic conditions.