La conception des bâtiments à faible consommation d'énergie est devenue un enjeu très important à travers le monde afin de minimiser la consommation d'énergie et les émissions de gaz à effet de serre associés. Au Maroc, le secteur du bâtiment représente 25% de la consommation énergétique finale du pays avec 18% réservée au résidentiel et 7% pour le tertiaire (ADEREE 2011). L'intégration de systèmes passifs ou semi-passifs de rafraîchissement/chauffage dans le bâtiment est désormais indispensable pour la réduction de la consommation énergétique tout en améliorant le confort thermique. Un de ces systèmes est l’échangeur air-sol (EAHX). Le principe du rafraîchissement à l'aide de l’échangeur air-sol est bien établi, mais le comportement d'un tel système dépend des conditions climatiques et de la nature du sol. L’échangeur air-sol étudié est installé dans une maison type villa située dans la banlieue de Marrakech. Un monitoring de ce système a été réalisé durant l’été 2013 à travers un suivi des températures et de l'humidité durant 39 jours. Les résultats montrent que l’échangeur air-sol est un système adapté pour le rafraîchissement de l’air dans les bâtiments à Marrakech, puisqu’il procure une température de soufflage quasi-constante d’environ 22°C pour le débit 244 m3/h et 25°C pour le débit de 312m3/h, avec une humidité relative autour de 50 % alors que la température extérieure dépasse 40°C. Le modèle mathématique choisi et l’outil de simulation associé, Type 460 opérant sous le logiciel commercial TRNSYS, sont analysés et validés par confrontation avec les résultats expérimentaux. Cette confrontation a montré une excellente concordance, avec un écart absolu moyen entre la mesure et la simulation toujours inférieur à 0,5°C et décroit à 0,2°C à la sortie de tube enterré. La validation de l’outil de simulation avec un échangeur air-sol enterré dans un sol soumis à conditions météorologiques extérieures n’a pas été réalisée auparavant. D'autre part, les simulations dynamiques de l’échangeur air-sol sont réalisées en fonctionnement continu, avec 1 et 3 tubes durant la période chaude de l’année (mai-septembre). Les résultats montrent que le système procure une température à la sortie de tube enterré de 25,1°C (1 tube) et 26 °C (3 tubes). Il en résulte une capacité de refroidissement de 58w/m2 (1 tube) et 55w/m2 (3 tubes) pour une température à l’entrée de 44,6°C. Une étude de sensibilité, utilisant la méthode de Sobol, de la performance thermique de l'échangeur durant la saison chaude (mai-septembre) a permis de dégager les paramètres les plus influents. Par la suite, une étude paramétrique complète sur l’énergie sensible totale perdue par l’air lors dans son passage dans l’échangeur air-sol est réalisée en fonction des paramètres les plus influents déterminés auparavant. / The low energy buildings tendency has become a major worldwide key to minimize energy consumption and greenhouse gas emissions issues. In Morocco, the building sector represents 25% of the total final energy consumption, whereas 18% is dedicated for residential and 7% for the tertiary sector (ADEREE 2011). The integration of passive or semi-passive for cooling/heating purposes into buildings is an essential act for reducing energy consumption while improving thermal comfort. One of these systems is the Earth to Air Heat Exchanger (EAHX). Its principle to use the ground-coupled heat exchanger for cooling is well established, but the behavior of such a system depends on the climate and the soil, which influences the choice of design parameters of this system. We performed a numerical and experimental study on the thermal performance of an Earth to air heat exchanger installed in a villa type house in the suburbs of Marrakech. A monitoring survey was conducted during the summer period of 2013, to acquire temperature and humidity measurements for 39 days. The results show that the earth to air heat exchanger is a system more adapted to refresh the air in buildings in Marrakech, as it provides a quasi constant air temperature of approximately 22°C for flow 244 m3/h and 25°C for flow of 312 m3/h, with relative humidity that is around 50% when the outside temperature exceeds 40°C. The mathematical model chosen and the associated simulation tool used is Type 460 operating under the TRNSYS commercial software, analyzed and validated by comparison with experimental results. This comparison showed excellent agreement, with an average absolute difference between the measurement and simulation that is always lower than 0.5°C and 0.2°C as it decreases at the output of the buried pipe. On the other hand, dynamic simulations of the EAHX using TRNSYS software (TYPE 460) were performed with one pipe or three pipes continuously running. The achieving specific cooling capacity is 58 W/m2 (one pipe) and 55 W/m2 (three pipes) obtained for air temperatures of 25 °C and 26 °C respectively, at the EAHX outlet and 44.6 °C at its inlet. A sensitivity analysis, using the method of Sobol, of the thermal performance of the earth air heat exchanger (EAHX) in the hot season (May-September) has identified the most influential parameters. Thereafter, a complete parametric study on the total sensible energy lost through the air when in passing through the air-ground heat exchanger is made based on the most influential parameters determined previously.

The world is currently submerged in two big problems: supply energy crisis and climate change. It is clear that society has to do its best to overcome these challenges, and one effective way to mitigate their effects is by conducting an energy audit, which helps to identify the weaknesses and strengths of the buildings, enabling improvements in their thermal efficiency.  The main goal of this study was to carry out an energy audit on a century-old single- family house located in a city in the middle of Sweden. To achieve this, relevant data of the building was gathered such as the bills and some temperature and dimension measurements. Subsequently, the calculations of the energy losses and gains were done manually. From this step it was observed that almost 70 % of the thermal losses occurred due to transmission through the walls, windows and roof. To reduce these losses, potential energy-saving measures were studied, such as replacing the 2-panel windows with 3-panel windows and adding 200 mm of mineral wool to the roof. Both improvements reduced transmission losses around 700 kWh/year and diminished CO2 emissions around 20 kg/year, which implied a decrease of 1262 and 1277 SEK per year for each measure respectively. However, the profitability of these measures was difficult to attain because the required initial capitals are probably higher than the investments allowed, which are around 17371 and 17579 SEK for each measure respectively.  Moreover, a study about installing photovoltaic solar cells was conducted and it resulted in a significant positive impact in the energy usage of the house. In particular, this improvement lead to a reduction of 2471 kWh per year, which equaled to an annual decrease of 6036 SEK. These annual savings implied an investment allowed of 58620 SEK. Furthermore, a decrease of 99 kg of CO2 emissions per year was obtained. In conclusion, this measure yielded substantial profitability, making it the most recommended option for future energy-saving improvements.  Finally, changing in the occupant’s behavior by reducing the indoor temperature had a positive impact on the house without the need for an initial investment. Specifically, it decreased around 105 kWh per year.

<p dir="ltr">Personalized thermal controls are beneficial for occupant comfort and productivity in office buildings. Recent research efforts on learning personal thermal comfort support the integration of personalized preferences in optimal building control and further implementation in real buildings. This Thesis presents the development and field implementation of personal preference-based thermal control in real offices, emphasizing the role of model predictive control (MPC) and low-cost local sensing. Probabilistic thermal preference profiles, a low-cost thermal sensing network and a MPC framework were integrated into a centralized building management and control system. The customized, preference-based HVAC control implemented in the offices indicated the comfort benefits of monitoring local thermal conditions (vs wall thermostats) for different preference profiles and showed 28-35% energy savings with personalized MPC (vs personalized static setpoint control).</p><p dir="ltr">Regarding the practical limitations in collecting sufficient data from occupants to train their thermal comfort model, we present a Bayesian meta-learning approach for developing reliable, data-driven personalized thermal comfort models using limited data from individuals. A high-dimensional neural network was developed, considering general thermal comfort impact factors (environmental variables, clothing level and metabolic rate) as well as personal thermal characteristics (expressed as a vector of continuous latent variables) as model inputs. The model parameters in the neural network were trained with subsets of ASHRAE RP-884 database. The trained neural network is transferrable, so that the thermal preferences of new individuals can be predicted by inferring their personal thermal characteristics using limited data. The results show that the developed Bayesian meta-learning approach to infer personal thermal comfort performs better than existing methods, especially when using limited data.</p><p dir="ltr">Moreover, this Thesis also discusses the potential of balancing thermal comfort and energy cost by setting dynamic temperature constraints in personalized MPC. A co-simulation framework of EnergyPlus and MPC is constructed using EnergyPlus Python API. Dynamic temperature constraints are selected based on personal thermal profile, weather conditions and utility rate variations. The performance of the personalized MPC with dynamic constraints demonstrates a balance between thermal comfort and energy cost in cooling season.</p>

According to the U.S. energy consumption survey in 2012, about 25% of the commercial and 42% of the residential building energy were used for heating. Despite the development of new and more efficient Heating, Ventilation, and Air Conditioning (HVAC) systems over the years, the high energy consumption in heating is still one of the major energy efficiency issues. Studies showed that decreasing HVAC operating temperature set points by 4°F will result in energy savings of 15% or more. Thus, the smart localized heating control (SLHC) system was designed and prototyped to provide localized heat directly to a person so that HVAC can run at a lower temperature set point. SLHC detects human movement and delivers the heat based on the result of the target location estimation and temperature measurement feedback. To detect the human movement, image processing techniques were used; image segmentation, mass center detection, background subtraction using the Mixture of Gaussian model, and human feature detection. In SLHC, a near-infrared heater and a tracking function were used to provide an instant and a direct heat to the person in order to minimize wasting energy. The SLHC system is divided into the sensing and processing (SP) and the heating and regulating (HR) subsystem. The SP’s primary function is to process captured video images and measured temperature data. SP also generates and sends the heater operating signal to HR. HR purposes to control the heater’s direction and power based on the signal. The communication between SP and HR was established through Wi-Fi enabled development platform. The SLHC prototype successfully processed the sensing data and transmitted the control signal. The result shows that it detected human movement and estimated the person’s location in 3D space within 10% margin of error. Also, it delivered the focused heat to the surface of the human body and increased the temperature by 10.0°F in 3 minutes at the distance of 1.5m away from the heater. This cost-effective, wireless, and localized heating system demonstrates the potential to improve energy efficiency in buildings. / Electrical and Computer Engineering

Le contexte d’application de cette recherche a été le projet CRIBA. CRIBA vise à industrialiser une solution intégrée de rénovation et d’isolation de grands bâtiments. De ce fait, une part importante de la valeur ajoutée est transférée des chantiers de rénovation vers des usines de fabrications devant être synchronisées avec les chantiers. La planification est l'une des étapes importantes de la gestion de projets. S’adaptant à une organisation, elle vise une réalisation optimale en considérant les facteurs de temps, coût, qualité ainsi que l’affectation efficace des ressources. Cette affectation est d’autant plus complexe lorsqu’un ensemble de projets se partagent les ressources, renouvelables ou non renouvelables. L'objectif global de notre étude est de développer un outil d’aide à la décision pour un décideur visant à planifier plusieurs projets en intégrant l'allocation des ressources renouvelables, et la planification des flux de ressources non-renouvelables vers ces projets. Dans ce cadre, les ressources non renouvelables telles que les machines et la main-d'œuvre ont une disponibilité initiale limitée sur les chantiers. Cependant, nous supposons que des quantités limitées supplémentaires peuvent être achetées. En outre, nous prenons en compte la volonté des coordinateurs des projets pour l’approvisionnement des chantiers en juste à temps (just in time), en particulier pour les ressources peu demandées, encombrantes et à forte valeur. Ceci oblige à étendre le cadre du modèle de la planification des projets en incluant la planification de la chaîne logistique qui approvisionne les ressources non renouvelables des chantiers. Enfin, pour répondre au besoin d’outils décisionnels responsables sur le plan environnemental, le modèle prévoit le transport et le recyclage des déchets des chantiers dans les centres appropriés. Un modèle linéaire mixte du problème est ainsi posé. Puisqu’il rentre dans la classe des modèles d'optimisation NP-durs, une double résolution est proposée. D’abord à l’aide d’un solveur puis une méta-heuristique basée sur un algorithme génétique. De plus, pour faciliter l'utilisation du modèle par des utilisateurs peu familiers avec la recherche opérationnelle, un système d'aide à la décision basé sur une application web a été développé. L’ensemble de ces contributions ont été évaluées sur des jeux de test issus du projet CRIBA. / The application context of the current study is on a CRIBA project. The CRIBA aims to industrialize an integrated solution for the insulation and thermal renovation of building complexes in France. As a result, a significant part of the added value is transferred from the renovation sites to the manufacturing centers, making both synchronized. Planning is one of the important steps in project management. Depending on the different viewpoints of organizations, successful planning for projects can be achieved by performing to optimality within the time, cost, quality factors as well as the efficient assignment of resources. Planning for the allocation of resources becomes more complex when a set of projects is sharing renewable and non-renewable resources. The global objective of the study is to develop a decision-making tool for decision-makers to plan multiple projects by integrating the allocation of the renewable resources and planning the flow of non-renewable resources to the project worksites. In this context, non-renewable resources such as equipment and labor have a limited initial availability at the construction sites. Nevertheless, we assume that additional limited amounts can be added to the projects. In addition, we take into account the interest of the project coordinators in supplying the non-renewable resources in a just-in-time manner to the projects, especially for low-demand resources with a high price. This requires extending the framework of the project planning by including the planning of the supply chain which is responsible. Finally, in order to meet the requirements for environmentally responsible decision-making, the model envisages the transportation and recycling of waste from project sites to appropriate centers. A mixed integer linear model of the problem is proposed. Since it falls within the class of NP-hard optimization models, a double resolution is targeted: first, using a solver and then a metaheuristic based on the genetic algorithm. In addition, in order to facilitate the use of the model by users unfamiliar with operational research, a web-based decision-making support system has been developed. All the contributions are evaluated in a set of case studies from the CRIBA project.

The building sector is one of the sectors with the highest energy utilization and is one of the largest sources of CO2 emissions worldwide. At the same time, energy prices in Europe have significantly increased in recent years. For these two reasons, energy efficiency in buildings has become highly relevant for public and private organizations aiming to reduce energy consumption for the operation of buildings and therebyd ecrease their carbon footprint and operation costs for users and owners. This master’s thesis aims to identify areas of opportunity for energy utilization reduction and the implementation of energy efficiency strategies in four buildings of the KTH Campus, owned by Akademiska Hus. First, an energy data analysis of the last years of the operation of the buildings was conducted to identify trends and atypical energy uses. Next, energy audits were performed on the most important energy-consuming equipment and major building facilities to understand the operation conditions and characteristics of electrical, heating, and cooling systems, aiming to identify areas of opportunity for reducing energy use from current operation of the buildings. Subsequently, after understanding the energy use in the four buildings, models of the buildings were created in IDA ICE. The approach involved two steps: first, modeling the buildings’ geometry and adapting their energy consumption to match the patterns identified in the previous data analysis; and secondly, modeling the implementation of energy efficiency strategies on the buildings that aim to improve the findings of the data analysis and energy audits performed previously. These energy efficient models were subjected to energy performance analysis, economic analysis, investment feasibility analysis, among others. The results obtained from the models with energy efficiency strategies showed energy and economic savings that varied from building to building through the automation of lighting systems in the buildings, with an average return on investment of 2.5 years. Likewise, significant savings were achieved by reducing the heating setpoint during nights, causing the district heating usage to differ from the daytime demand, resulting in savings between 5 % and 8 % of the total annual energy use in the buildings, without any required investment. Additionally, the implementation of renewable energy solutions was studied by modeling the use of solar panels in the buildings, leading to a reduction in electrical grid demand between 20 % and 48 %, depending on the available area for the panels, with an average return on investment of 5.5 years. Other strategies were also studied and discussed in this report. In conclusion, this study provides evidence of the energy, economic, and environmental feasibility of different energy efficiency strategies that can be implemented in the buildings of the KTH campus. These strategies contribute to achieving the environmental objectives of Akademiska Hus and KTH. / Byggnadssektorn är en av de sektorer som har högst energianvändning och är en av de största källorna till utsläpp globalt. Samtidigt har energipriserna i Europa ökat avsevärt de senaste åren. Av dessa två skäl har energieffektivitet i byggnader blivit mycket relevant för offentliga och privata organisationer som strävar efter att minska energiförbrukningen för byggnaders drift och därigenom minska deras koldioxidavtryck och driftskostnader för användare och ägare. Denna master avhandlingsyftar till att identifiera möjlighetsområden för minskning av energianvändning samt implementering av energieffektivitetsstrategier i fyra byggnader på KTH Campus, ägda av Akademiska Hus. Först genomfördes en analys av energidata från de senaste åren av byggnadernas drift för att identifiera trender och otypisk energianvändning. Därefter utfördes energirevisioner av de mest betydande energiförbrukande utrustningarna och huvudsakliga byggnadsanläggningarna för att förstå driftsförhållandena och egenskaperna hos elektriska, uppvärmnings- och kylsystem. Syftet var att identifiera möjlighetsområden för att minska energianvändningen från nuvarande drift av byggnaderna. Efter att ha förstått energianvändningen i de fyra byggnaderna skapades modeller av byggnaderna i IDA ICE. Tillvägagångssättet innefattade två steg: först att modellera byggnadernas geometri och anpassa deras energiförbrukning för att matcha de mönster som identifierades i den tidigare dataanalysen. Sedan modellering av implementeringen av energieffektivitetsstrategier på byggnaderna, som syftar till att förbättra resultaten av den tidigare utförda dataanalysen och energirevisionerna. Dessa energieffektiva modeller underkastades analys av energiprestanda, ekonomisk analys, investeringsmöjlighetsanalys, bland andra. Resultaten som erhölls från modellerna med energieffektivitetsstrategier visade på energi- och ekonomiska besparingar som varierade från byggnad till byggnad genom automatisering av belysningssystemen i byggnaderna, med en genomsnittlig avkastning på investeringen på 2.5 år. På samma sätt uppnåddes betydande besparingar genom att sänka uppvärmningsinställningen under nätterna, vilket fick fjärrvärmeförbrukningen att skilja sig från dagtidens efterfrågan och resulterade i besparingar mellan 5 % och 8 % av den totala årliga energianvändningen i byggnaderna, utan någon nödvändig investering. Dessutom studerades implementeringen av förnybara energilösningar genom modellering av användningen av solpaneler i byggnaderna, vilket ledde till en minskning av elnätets efterfrågan med mellan 20 % och 48 %, beroende på tillgänglig yta för panelerna, med en genomsnittlig avkastning på investeringen på 5.5 år. Andra strategier studerades också och diskuterades i denna rapport. Sammanfattningsvis ger denna studie bevis på energi-, ekonomi- och miljömässig genomförbarhet av olika energieffektivitetsstrategier som kan implementeras i byggnaderna på KTH Campus. Dessa strategier bidrar till att uppnå miljömålen för Akademiska Hus och KTH.

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The diploma thesis on „Optimizing of shopping center energy demands“ deals with the reduce of the energy demand of the shopping center. The theoretical part describes the possibilities of reducing the energy intensity in terms of renewable resources, the potential of renewable resources. In practical part the energy audit of the existing building is designed, then the possibilities of reducing the energy intensity of the building, the budget and expressed return on investment by means of the net present value, the internal rate of return and simple payback period.