The cohesive urban social fabric between local architectural identity and climatic response

Ponència presentada a la sessió

Improving thermal comfort conditions through the optimization of the self-product residential buildings envelope. Case of a region with a hot and arid climate: Biskra

To improve the thermal comfort conditions of the occupants in the individual housing and to reduce the energy consumption induced by the heating and cooling needs in the building, it is necessary to act on the main element which controls the heat exchanges with the environment: the envelope. This refers to the building’s outer skin that consisting of vertical opaque components (the walls ...), horizontal ones (roof ...) and various opening devices. The thermal performance of the envelope is mainly due to its geometrical and formal attributes, but the material characteristics of its components remain decisive for thermal exchanges with the environment. As part of the building at the interface of the indoor ambiances and the outdoor environment, the envelope is often the seat of a large number of heat exchange phenomena that affect not only the premises energy consumption but also the thermal comfort conditions of their occupants. This paper summarizes the main results obtained from an in-situ measurement campaign to evaluate the design parameters influencing the thermal comfort of self-produced individual housing relative to the hot and arid climate of Biskra. In addition, a thermal simulation carried out with the TYRNSYS 17 software has demonstrated the potential of improving the thermal comfort conditions of the self-produced individual housing thanks to adequate choices concerning the architectural and constructive attributes of the envelope

The Cohesive Urban Social Fabric Between Local Architectural Identity and Climatic Response

Mario Botta once said: «Architecture is the constant fight between man and nature, the fight to overwhelm nature, to possess it. The first act of architecture is to put a stone on the ground. That act transforms a condition of nature into a condition of culture; it’s a holy act». Through history, we see this interaction between us, nature and culture, this complicated relation shapes our life into social urban fabrics and architecture. Therefore, Architectural heritage is the most witness and expressive art and science to human being’s history book. Since our environments are different, the logical consequence of urban fabrics also would be different in point of view the compactness, units’ form, materials, urban layout and streets. For example, the Saharan urban fabrics seems to be more compact with narrow streets and patio-built units, this urban fabric are also a result of social order needs, the hierarchy of streets from public to private shows the intimacy relation between local habitants and visitors, public spaces for social gathering like plazas assure the mix use of spaces, the preservation of landscape of local environment to integrate the design with nature and to demonstrate agriculture spaces in that fabrics. Therefore, to clarify this crossed complex fabrics we should find the harmonic serrated wheels which touch this elements or criteria. The architectural community has had a strong and continuing interest in traditional and vernacular architecture. This has been rekindled by the need to develop an architecture that works with climate, rather than against it, to create more sustainable buildings. Earlier research and existing publications on traditional or vernacular architecture have followed an anthropological or archaeological approach, whereas books on climatic design and sustainable architecture tend to refer to contemporary principles and built precedents without direct reference to past experience.Peer Reviewe

The effect of cool paints and surface properties of the facade on the thermal and energy efficiency of buildings in a hot and arid climate

The facade of a building is a decisive factor in the thermal and energy performance of buildings. Its surfaces are considered as zones of heat transfer between the inside and the outside. Surface properties, especially color and texture; which have an important role on solar absorption and thermal emittance of the facade and subsequently the thermal operation of the building. The purpose of this article is to study the impact of surface properties of the facade on the thermal comfort and energy efficiency of buildings in a hot and arid climate. The investigation is based on an experimental approach by taking measurements in test cells with an insulating paint (with nanoparticles) as well as on a numerical study by the dynamic thermal simulation software TRNSYS. Several parameters were studied such as ambient temperature, internal and external surface temperature and energy consumption. The results showed that the surfaces of the facade represent with excellence the place of heat exchange between interior and exterior whose surface properties have a colossal impact on the thermal and energy operation of the building. The insulating paint with its nanoparticles has a considerable impact on the reduction of temperature. The proper choice of material absorption has a great influence on the reduction of temperatures and energy requirements of the building

Study and optimization of the windows’ impact on thermal comfort and energy efficiency (Case of offices in a hot and arid climate)

Controlling the thermal environment and reducing the energy consumption of buildings across the façade are a difficult challenge for architects, especially in a desert climate. The windows in particular play an important role in the tandem of the thermal operation of the building and the comfort of the users. The objective of this article is to study and optimize the impact of windows, their material and proportional characteristics on the thermal comfort and energy efficiency of office buildings in a hot and arid climate. The investigation is based on an empirical approach (measurements taken in situ on real cases) as well as on a numerical simulation study with the TRNSYS program. Several parameters have been studied such as surface temperature, ambient temperature and energy consumption. The results showed that facade windows are a determining factor in the thermal exchanges between the building and its environment and that the key parameters that condition these exchanges are the windows ratio (glazed area) and the type of glazing. The judicious choice of the windows ratio combined with an appropriate choice of the type and composition of the glazing improves the thermal comfort of the users and ensures the energy performance of the building

The effect of cool paints and surface properties of the facade on the thermal and energy efficiency of buildings in a hot and arid climate

The facade of a building is a decisive factor in the thermal and energy performance of buildings. Its surfaces are considered as zones of heat transfer between the inside and the outside. Surface properties, especially color and texture; which have an important role on solar absorption and thermal emittance of the facade and subsequently the thermal operation of the building. The purpose of this article is to study the impact of surface properties of the facade on the thermal comfort and energy efficiency of buildings in a hot and arid climate. The investigation is based on an experimental approach by taking measurements in test cells with an insulating paint (with nanoparticles) as well as on a numerical study by the dynamic thermal simulation software TRNSYS. Several parameters were studied such as ambient temperature, internal and external surface temperature and energy consumption. The results showed that the surfaces of the facade represent with excellence the place of heat exchange between interior and exterior whose surface properties have a colossal impact on the thermal and energy operation of the building. The insulating paint with its nanoparticles has a considerable impact on the reduction of temperature. The proper choice of material absorption has a great influence on the reduction of temperatures and energy requirements of the building

Towards an Understanding of the Local Interpretations of the Arab Mosque Model in the Saharan Regions. Re-exploration of the Ziban in South-Eastern Algeria

The architecture of the Arab mosque has been interpreted in two different ways. In major capitals, the mosques were constructed under the patronage of the rulers, who have given them a monumental appearance. It was the time of the emergence of the so-called “Hispano-Maghreb” or “Hispano-Moorish” style that reflected the potency and the prestige of the rulers. In contrast, in villages and hamlets, the adoption of the Arab mosque model was a vernacular art, as is the case in the Saharan regions of Algeria. This article investigates the local interpretations of the Arab mosque model by taking the vernacular mosques of the Ziban region as a case study. The research followed both historical and visual approaches, and the data were collected from travelogues, graphic documents, architectural surveys, old and current photographs, and the interrogation of the residents. The findings demonstrated that the early mosque of Okba Ibn Nafaa served as a generative model for subsequent mosques in the Ziban. It gave birth to the “Saharan style,” which is characterised by the use of vernacular building materials of clay and palm wood. In addition, the investigation revealed that the reuse of Roman ruins is a very old practice in the Ziban, as evidenced by the many mosques located in the ksour near the Limes line. Interpretazioni locali del modello di moschea araba nelle regioni sahariane. Ri-esplorazione dello Ziba nel sud-est dell’AlgeriaL’architettura della moschea araba è stata interpretata in due modi diversi. Nelle grandi capitali, le moschee venivano costruite sotto il patrocinio dei sovrani, che conferivano loro un aspetto monumentale. Era l’epoca dell'emergere del cosiddetto stile “ispano-maghrebino” o “ispano-moresco” che rifletteva la potenza e il prestigio dei governanti. Al contrario, nei villaggi e nelle frazioni, l’adozione del modello di moschea araba era un'arte vernacolare, come nelle regioni sahariane dell’Algeria. Questo articolo indaga le interpretazioni locali del modello di moschea araba prendendo come caso di studio le moschee vernacolari della regione di Ziban. La ricerca ha seguito approcci sia storici che visivi e i dati sono stati raccolti da diari di viaggio, documenti grafici, rilievi architettonici, fotografie d’epoca e interrogando i residenti. I risultati hanno dimostrato che la prima moschea di Okba Ibn Nafaa è stata un modello generativo per le successive dello Ziban. Queste moschee sono caratterizzate dall'uso di materiali da costruzione vernacolari di argilla e legno di palma. Inoltre, l’indagine ha rivelato che il riutilizzo delle rovine romane è una pratica molto antica nello Ziban, come dimostrano le numerose moschee situate nei ksour, vicino alla linea del Limes.The architecture of the Arab mosque has been interpreted in two different ways. In major capitals, the mosques were constructed under the patronage of the rulers, who have given them a monumental appearance. It was the time of the emergence of the so-called “Hispano-Maghreb” or “Hispano-Moorish” style that reflected the potency and the prestige of the rulers. In contrast, in villages and hamlets, the adoption of the Arab mosque model was a vernacular art, as is the case in the Saharan regions of Algeria. This article investigates the local interpretations of the Arab mosque model by taking the vernacular mosques of the Ziban region as a case study. The research followed both historical and visual approaches, and the data were collected from travelogues, graphic documents, architectural surveys, old and current photographs, and the interrogation of the residents. The findings demonstrated that the early mosque of Okba Ibn Nafaa served as a generative model for subsequent mosques in the Ziban. It gave birth to the “Saharan style,” which is characterised by the use of vernacular building materials of clay and palm wood. In addition, the investigation revealed that the reuse of Roman ruins is a very old practice in the Ziban, as evidenced by the many mosques located in the ksour near the Limes line

The effect of building materials choice on the thermal comfort in the auto-produced individual housing in Biskra.

The building envelope is the first barrier to protect against external climatic variations. Generally, it consists of two types of walls: opaque walls (walls and roof) and transparent walls (Windows). The design characteristics of the enclosure strongly affect the occupants' thermal comfort, as well as the building energy consumption. The constructive choices relating to structural elements, in particular, walls, roofing and openings are generally considered in the thermal exchanges between the building and its environment. In the present study, which is based on experimental analysis in the self-generated residential sector in Biskra (Algeria), where a warm and arid climate predominates, we aim to evaluate the thermal impact of certain architectural and constructive parameters that are specific to residential habitat self-produced in Biskra. This paper summarizes the main results obtained from an in situ measurement campaign that evaluated the essential parameters of thermal comfort such as ambient and surface temperature, air velocity, and humidity. These parameters were used as indicators to measure the impact of the envelope material characteristics on its climatic adaptability. This paper also presents some recommendations for optimizing the choice of building materials specific to the self-produced residential in order to improve its thermal performance while preserving the essentials of its specificities

Impact of passive cooling techniques on the thermal behavior of residential buildings in hot and arid regions -An experimental study-

The thermal performance of the roof is one of the most important factors for a comfortable environment. As 50% of the thermal loads received by a building come from the roof, this research seeks to find the roofing system that opposes the transmission of heat during the hottest days and promotes indoor thermal comfort. In this regard, this paper presents an experimental study carried out on four (04) testing cells constructed on a reduced scale and submitted to climatic external conditions. Three (03) cells were used to test passive cooling strategies through the roof, namely: the cool roof, ventilated roof and a roof with inverted earth pots. The fourth cell that served as cell-reference, for its part, a conventional roof. The experimentation concerned the types of roofs most used in residential buildings in Biskra, Algeria. The measurements process was effectuated in an exposed field during the month of July, prevailing the metrological data of the hot and arid climate. The obtained results show that the use of the cool-roof technique makes it possible to record the lowest internal temperatures in comparison with the other systems. Thus, the reflective coating technique is capable of reducing the internal temperature from 3.33 °C to 4.80 °C, also the internal and external surface temperature of the roofs from 5.31 °C to 10.18 °C, respectively. These experimental results confirm the effectiveness of the "cool roof" technique as an innovative and efficient solution that contributes to the achievement of the comfort conditions in a hot and arid climate by eliminating heat gains through the roof

VERS UNE GENEALOGIE DE L’ARCHITECTURE DOMESTIQUE A BISKRA

Cet article est basé sur un travail de doctorat en cours de finalisation qui porte sur l’architecture domestique à Biskra. Il présente les résultats relatifs au premier pôle de la recherche lequel caractérise morphologiquement le cadre bâti résidentiel autoproduit (habitat populaire) et met en exergue les modalités de son évolution. La méthode utilisée pour étudier les mutations de l’espace bâti domestique est d’essence typologique. Néanmoins le modèle analytique élaborée présente l’intérêt de prendre en charge à la fois dimension temporelle diachronique et la dimension morphologique ramenée à trois variables génériques - i) l’insertion urbaine, ii) l’apparence extérieure, iii) l’organisation intérieure . L’esprit de la démarche consiste à étudier l’habitation populaire comme la somme de strates historiques successives dont les traits morphologiques pertinents sont caractérisés. L’article donne un aperçu sur l’approche méthodologique adoptée, des résultats préliminaires sont également présentés