No description available.

Hotel buildings were identified as significant energy consumers. Within the theoretical framework of the thesis it was argued that climate change and increasing energy prices due to depletion of fossil fuels would cause pressure on hotel operations in Cyprus by increasing their cooling loads and operational costs. The analysis was techno-socio-economic and the core aim was to evaluate the costeffectiveness of selected energy saving strategies. These were in the form of building envelope upgrades, changes in indoor environmental criteria and introduction of renewable energy technology via solar air-conditioning to be implemented as part of the hotels’ periodic scheduled building and systems upgrades with the aim of lowering their space conditioning energy costs and improving their profitability and competitiveness. The applied methodology consisted of auditing of a case study hotel, energy consumption data collection both from a sample of hotels and industry-wide and a hotel guest survey. Thermal simulation of hotels in present and future climates was used to identify technically viable renovation strategies. Strategies found cost-effective were further checked for sensitivity to energy prices, hotel occupancy and climate. The major findings of the thesis predict over 20% savings in space conditioning energy costs due to strategic building envelope upgrades, over 50% savings if in addition adjustments in thermal comfort criteria are included and over 80% savings if solar AC is added into the above. It was further found that with a minimal increase in room rates hotels could implement thermal renovation while maintaining or even increasing room income. A unique cost-efficiency indicator that measures profitability of the proposed energy saving strategies in terms of hotels’ room income generation potential was developed in this thesis. Finally, if the suggested renovations were implemented on a mass scale, one quarter of Cyprus’ national energy saving and renewable energy targets could be met.

This thesis investigates the use of agricultural waste materials as alternative raw material for thermal insulation for dwellings in Thailand. A literature review carried out to study the potential of several agricultural waste materials suggested that coconut husks, bagasse and rice hulls offer high potential due to their availability in Thailand, low thermal conductivity, and ability to be made into low density boards. The Life Cycle Assessment (LCA) was carried out to compare the environmental and health impacts of thermal insulation boards made from agricultural waste materials currently available on the market with conventional insulation materials. This suggested that the currently available thermal insulation boards made from agricultural waste materials generally had more environmental and health impacts than conventional insulation materials. However, coconut husks and bagasse showed potential; the environmental and health impacts of the insulation boards made from these materials were low and could be lower provided that they were produced with lower thermal conductivity and lower density and without chemical binder. Low-density binderless thermal insulation boards were then developed from coconut husks and bagasse using a hot pressing method with varying hot pressing conditions. The results showed that board density, hot pressing temperature and pressing time were associated with the physical properties of both coconut husk and bagasse insulation boards, including modulus of rupture, modulus of elasticity and internal bond. It was also found that while both binderless coconut and bagasse insulation boards had thermal conductivity values in the same range as those of conventional insulation materials, the binderless bagasse insulation boards had better mechanical properties than coconut boards. Binderless bagasse insulation boards produced at a density of 350 kg/m3 treated at a hot pressing temperature of 200°C for 13 min could satisfy the requirements of JIS A 5905:2003 Insulation Fibreboards except for thickness swelling. LCA was carried out for two potential bagasse insulation boards (350 and 230 kg/m3 density) in comparison with conventional insulation materials. The results suggested that a board of 230 kg/m3 density offers lower environmental impacts than cellulose, fibreglass and rock wool insulations. The outcome of this study indicates that bagasse, an agricultural waste material, has significant potential as alternative raw material for thermal insulation production in the context of Thailand.

This study investigated the use of modulated solar shielding in the context of solar radiation control in hot-dry and semi-arid climates. Solar shielding refers to the solar protection of the entire or large parts of the building's external fabric and not just those elements which directly transmit solar radiation. The study was undertaken with particular reference to the hot semi-arid climate of northern Nigeria. A conceptual and climatic analysis provided a contextual background for the work. A study of the use of shading devices indicated that their strength in some climates may be their weakness in others, especially the hot dry and semi and climates. A multiplicity of inherent climatic and environmental elements were not fully addressed by formal shading techniques. The concept of solar shielding was conceived from the interplay of the climatic and environmental factors of hot dry and semi-axid lands. Lack of measured solar radiation data in the reference climate necessitated the development of an interactive computer program to generate this and other relevant design data. A literature review provided a theoretical foundation un- derpining a series of full scale field measurements, scale model experimentation and thermal simulation studies. Fill scale measurements in a building were instructive on a possible impact of solar shielding on indoor thermal conditions. Model scale wind tunnel tests on the reference building and studies on full size louvres, using a pressurisation test facility, culminated in the development of airflow models through louvres. Finally, parametric thermal modelling studies enabled not only the optimisation of the technique but also a comparison with formal shading methods. Measured and simulated data portrayed not only a significant agreement but also indicated that solar shielding could have a higher solar protection efficiency than shading devices.

Le travail de thèse porte sur l’optimisation des consommations d’énergie de chauffage dans le logement social. Il s’inscrit dans une démarche globale de réduction des consommations d’énergie. Ce travail a été réalisé grâce à une collaboration entre l’Université de Lille et le bailleur Lille Métropole Habitat. Il s’appuie sur une instrumentation des logements occupés afin d’explorer les possibilités de réduction des consommations à travers le contrôle du système de chauffage et la sensibilisation des occupants. Le travail comporte 4 parties. La première partie comprend une étude bibliographique sur la précarité énergétique dans le logement social ainsi que les réglementations thermiques. La deuxième partie présente le site d’étude qui sert de support pour cette thèse. Cette partie décrit la méthode expérimentale et le système d’instrumentation utilisé pour réaliser les mesures du confort thermique. La troisième partie comporte une analyse de la température et de l’humidité relative pendant les différentes saisons. L’étude montre des périodes de surchauffe, qui se traduisent par des surconsommations. La dernière partie s’appuie sur le logiciel de simulation thermique dynamique Archiwizard. Elle montre le calage des paramètres numériques sur les mesures, ensuite elle donne une estimation des économies potentielles que nous pouvons réaliser par la simple application de la réglementation thermique. / This work concerns the optimization of heating energy consumption in social housing.It is a part of a global approach to reduce energy consumption in social housing. It was realized within a collaboration between Lille University and Lille Métropole Habitat. The research is based on monitoring occupied dwellings to explore the possibilities of reducing energy consumption through control of the heating system and the implication of tenants. This thesis is composed of four parts. The first part includes a literature review concerning energy precarity in social housing and thermal regulations. The second part presents the social housing residence used in this research. It presents in details the monitoring system and the experimental protocol used to follow the comfort conditions in the residence. The third part presents analysis of temperature and relative humidity recorded in three apartments. Analysis shows an overheating during the heating period, which leads to important increase in the heating expenses. The last part presents thermal simulation using the software “Archiwizard”. It shows the calibration of the numerical model as well as an estimation in heating energy savings.

This thesis examines the use of aerial thermography data to discriminate loft (attic) insulation levels in residential housing, with ventilated pitched roofs, in the UK. Quantitative techniques from the fields of remote sensing, GIS, building physics and atmospheric science were used to develop a methodology and analyse survey data flown over Nottingham in 2001. The quantitative techniques were applied to real survey data using the most up to date atmospheric propagation models. A new model of the heat loss through the ceiling, loft and roof was developed for this study, based on the most recent methods. The limitations of these techniques were explored. A complete methodology, valid for any future study, was defined. It was found that, measuring roof surface temperature from the thermal image was complicated by roof material properties, the intervening atmosphere and the surrounding topography. Relating roof surface temperature to insulation thickness was further complicated by loft space ventilation and the outside surface heat balance. The additional data, needed to quantify the results, produced inaccuracies caused by measurement error. Analysis of the uncertainties, by simulation, indicated that loft insulation level could not be discriminated by aerial thermography. This was confirmed by comparing the results, calculated from the survey data, with the actual insulation level for a number of houses in test areas of the city.

The world is facing increasing pressures to reduce the amount of energy and resources that are being used. The UK government has targets to reduce carbon emissions and energy usage. Within the UK buildings are a significant contributor towards both energy and material usage. One approach to reduce the energy and carbon emissions from construction is to use natural materials that require minimal processing and energy input such as straw, timber, unfired earth and hemp-lime. Hemp-lime is a composite solid wall insulating material made from hemp shiv and a lime based binder and water which can be cast between shutters or spray applied. Hemp-lime is typically used with a load bearing timber studwork frame. Current design practice assumes that hemp-lime is a nonstructural material and only provides the insulation to the wall construction. However, as it encapsulates the studs it has to potential to enhance their load capacity by preventing buckling and resisting in-plane forces. This study aimed to establish the contribution of the hemp-lime to the structural performance of composite hemp-lime and studwork frame walls under three loading conditions; vertical compression, in-plane racking and out-of-plane bending. Both theoretical analysis and experimental testing were undertaken in order to establish the contribution. Tradical HF hemp shiv and Tradical HB binder were used to mix hemplime with a density of 275kg/m3. The wall constructions were initially theoretically analysed using existing approaches and both the stiffness and strength of the wall panels were calculated. Experimental testing was undertaken on 24 full size wall panels. Fifteen were tested with compressive loads, five with in-plane racking loads and four with out-of-plane bending loads. Initially two walls were tested with a concentric compressive load applied to the top of the encapsulated timber studs. The studs were shown to be restrained by the hemp-lime preventing buckling and increasing the failure load by over 500%. Four walls were tested with eccentrically applied compressive loads to investigate bursting of the studs through the hemp-lime surface. On three walls the studs burst through the hemp-lime showing that bursting is dependent upon the hemp-lime cover over the studs. In addition unrestrained studs were tested and shown to buckle at much lower loads than the hemp-lime lime encapsulated studs. Under in-plane racking loads two walls were initially tested and found to have increased stiffness and strength over an unrestrained studwork frame. The leading stud joints were found to be a weak point. These joints were improved and two further walls were tested, one with a sheathing board attached to the studwork frame and one without. The strengthened joints were found to improve the stiffness and strength of the wall panels. The wall panel with sheathing was also found to have a higher stiffness than the unsheathed walls. Two walls were initially tested with applied out-of-plane loads. One wall was hemplime with rendered surfaces and the other included a studwork frame. The studwork frame was found to provide continued load capacity once the render and the hemp-lime had failed. Two further wall panels were tested with a sheathing board attached to the studwork frame and render on the other face of the hemp-lime. Again the studwork frames were found to provide post crack load capacity. The walls were also found to perform with differing stiffness according to the load direction. Following experimental testing the theoretical results were compared with the experimental results. Generally good correlation is seen between the results. Prior to the experimental testing it was not possible to predict the bursting of the hemp-lime when the studs were loaded in compression, however following testing a technique was developed to allow this prediction to be made. In conclusion this study has shown that hemp-lime does enhance the load capacity of studwork framing under both compressive and in-plane racking loads. Under out-ofplane bending loads the studwork frame allows continued load capacity after the hemplime and render have cracked. This study has shown that material savings can be made when using this type of construction as a sheathing board is not necessary as the hemplime can fulfil its structural function. This will contribute towards a more efficient construction system and reduced energy and resource use.

L’isolation thermique par l’extérieure (ITE) constitue une solution technique intéressante pour améliorer les performances énergétiques du secteur du bâtiment. Cependant, l’ITE peut venir modifier l’équilibre hygrothermique de l’enveloppe et affecter sa durabilité, notamment au regard de l’humidité. Dans ce contexte, un premier travail a consisté à étudier en laboratoire le comportement hygrothermique de trois systèmes d’ITE rapportés sur une paroi en parpaing : un système ETICS (PSE sous enduit mis en œuvre par voie humide) et deux systèmes sous bardage (mis en œuvre par voie sèche), dont un incluant des matériaux biosourcés (laine de bois et ouate de cellulose). Des expériences en enceinte biclimatique, combinées à des simulations numériques des transferts couplés de chaleur et de masse, ont permis d’appréhender le comportement hygrothermique de ces parois rénovées à différents stades : lors de la pose des solutions d’ITE, en usage « normal » et dans des conditions conduisant à des risques de condensation. Les résultats du système ETICS montrent le rôle important de la colle et la difficulté à appréhender numériquement son comportement. Les résultats des systèmes sous bardage soulignent l’intérêt d’utiliser des matériaux biosourcés dans des conditions à risques, mais également la sensibilité des simulations numériques aux propriétés hydriques des matériaux hygroscopiques. Un second travail portant sur l’analyse in situ d’un système d’ITE sous bardage a souligné l’absence de risques majeurs liés à l’humidité durant les deux années étudiées. Par ailleurs, la comparaison simulation/expérience a mis en évidence le rôle important joué par la lame d’air ventilée. / External thermal insulation (ETI) is an interesting technical solution for improving the energy performance of the building sector. However, ETI may change the hygrothermal balance of the envelope and affect its durability, especially with regard to moisture. With this in mind, a first work consisted in studying the hygrothermal behavior of three systems of ETI set on a hollow concrete block wall in the laboratory: an ETICS system (wet process) and two systems under cladding (dry process), with one of them composed with bio-based materials (wood wool and cellulose wadding). Experiments in a bi-climatic enclosure, combined with numerical simulations of coupled heat and mass transfers, made it possible to apprehend the hygrothermal behavior of these renovated walls at different stages: during the installation of ETI solutions, in "normal" use and under conditions leading to risks of condensation. The results of the ETICS system show the important role of the glue and the difficulty to understand numerically its behavior. The results of the cladding systems underline the interest of using bio-based materials under hazardous conditions, but also the sensitivity of numerical simulations to the hydric properties of hygroscopic materials. A second study on the in situ analysis of a cladding ETI system highlighted the absence of major risks related to humidity during the two years studied. In addition, the simulation / experiment comparison highlighted the important role played by the ventilated air.

L’inquiétude croissante concernant le futur des ressources énergétique a fait de l’optimisation énergétique une priorité dans tous les secteurs. De nombreux sujets de recherche se sont focalisés sur celui du bâtiment étant le principal consommateur d’énergie, en particulier à cause de ses besoins en chauffage. L’application des stratégies de contrôle et de gestion innovantes peuvent contribuer à des économies d'énergie. L'objectif de cette thèse est d'introduire le concept intelligent dans les bâtiments pour réduire la consommation d'énergie. L'étude vise à développer un modèle permettant de prédire le comportement thermique des bâtiments. La thèse propose une méthodologie basée sur la sélection des paramètres d'entrée pertinents, après une analyse de pertinence, pour développer un modèle simplifié de réseau de neurones artificiel, utilisé pour la prévision de température intérieure. Le domaine intelligent nécessite un processus automatisé pour comprendre la dynamique des bâtiments et décrire ses caractéristiques. L’utilisation des modèles thermiques réduits convient pour de telles stratégies. Ainsi, la thèse présente une étude préliminaire pour la génération d'un processus automatisé pour déterminer la prévision de température intérieure à court terme et les caractéristiques des bâtiments basées sur la modélisation en boîte grise. Cette étude est basée sur une méthodologie capable de trouver l'ensemble de données le plus fiable qui décrit le mieux la dynamique du bâtiment. L'étude montre que l'ordre le plus performant pour les modèles réduits est régi par la dynamique des données collectées utilisées. / With the highly developing concerns about the future of energy resources, the optimization of energy consumption becomes a must in all sectors. A lot of research was dedicated to buildings regarding that they constitute the highest energy consuming sector mainly because of their heating needs. Technologies have been improved and several methods are proposed for energy consumption optimization. Energy saving procedures can be applied through innovative control and management strategies. The objective of this thesis is to introduce the smart concept in the building system to reduce the energy consumption, as well as to improve comfort conditions and users’ satisfaction. The study aims to develop a model that makes it possible to predict thermal behavior of buildings. The thesis proposes a methodology based on the selection of pertinent input parameters, after a relevance analysis of a large set of input parameters, for the development of a simplified artificial neural network (ANN) model, used for indoor temperature forecasting. This model can be easily used in the optimal regulation of buildings’ energy devices. The smart domain needs an automated process to understand the buildings’ dynamics and to describe its characteristics. Such strategies are well described using reduced thermal models. Thus, the thesis presents a preliminary study for the generation of an automated process to determine short term indoor temperature prediction and buildings characteristics based on grey-box modeling. This study is based on a methodology capable of finding the most reliable set of data that describes the best the building’s dynamics. The study shows that the most performant order for reduced-models is governed by the dynamics of the collected data used.

L'objectif de cette thèse est la préparation d’aérogels biosourcés ayant des propriétés de super-isolation thermique. Pour cela, nous avons choisi de développer de nouveaux aérogels à base de nanofibres de cellulose (NFC). Les aérogels ont été préparés par lyophilisation. Dans un premier temps, une analyse des paramètres expérimentaux jouant un rôle sur la morphologie et les propriétés physico-chimiques des aérogels a été réalisée afin d’obtenir les meilleures propriétés d’isolation thermique. Avec une suspension de NFC à 2% en masse, sans ajout de sels et sans faire varier le pH, une lyophilisation réalisée dans des moules d’aluminium à une température de -80°C a permis d’obtenir des aérogels ayant une conductivité thermique de 0,024 W/m.K. Afin de diminuer cette conductivité thermique, nous avons choisi de réduire la taille des pores pour obtenir un effet Knudsen. Pour cela, une nouvelle technique de séchage a été proposée : la lyophilisation par pulvérisation. Les aérogels préparés dans les mêmes conditions expérimentales que précédemment avec cette technique ont des propriétés thermiques super-isolantes (0,018 W/m.K) grâce à la nano-structuration du réseau poreux. Finalement, un nouveau dispositif expérimental a été développé pour caractériser plus finement les propriétés thermiques des aérogels. C’est un dispositif transitoire impulsionnel qui permet d'estimer simultanément la contribution de la conduction solide et gazeuse, l'effet radiatif et la diffusivité thermique grâce à un modèle théorique simple. Ce dispositif permettra d’approfondir l’étude complexe du transfert thermique à travers des matériaux poreux semi-transparents tels que les aérogels. / The objective of this thesis is the preparation of renewable aerogels having thermal super-insulating properties. To do it, we designed new aerogels from nanofibrillated cellulose (NFC) by freeze-drying. This technique is simple and has the advantage of not using organic solvents. First of all, the parameters playing a role on the aerogel morphology and physico-chemical properties of the aerogels were analyzed to get the best thermal insulating properties. Using 2 wt% NFC suspensions, without addition of salts, keeping the initial pH, the obtained freeze-dried aerogels in alumina molds at -80 °C have a thermal conductivity of 0.024 W/m.K. In order to reduce the pore size and to improve the thermal insulating properties by Knudsen effect, a new drying technique was proposed: the spray freeze-drying. Aerogels prepared in the same experimental conditions with this technique have thermal super-insulating properties (0.018 W/m.K) thanks to the nanostructuration of the porous network. Finally, a new device was designed to characterize more precisely the thermal properties of aerogels. This is an impulsive transient device, which can estimate simultaneously the contribution of solid and gas conduction, the radiative effect and thermal diffusivity using a simple theoretical model. This device will allow studying complex heat transfer through porous semi-transparent materials such as aerogels