Rozprawy doktorskie na temat „Building Energy Exchange”

In 2013, Stockholms Hamnar began a development project for Värtahamnen, one of Stockholms most important harbors, and also decided to build a new ferry terminal that is better suited to meet the increasing capacity demand. The new terminal will feature a borehole storage that will be used to cover the building’s heating and cooling demands. The boreholes have already been drilled and currently the construction of the building is being planned. The overall objective of this project is to study the new terminal and its borehole storage regarding certain input parameters (such as internal heat gains and the U-value of windows) that affect the building’s annual heating and cooling demands, as well as long-term temperature of the borehole storage. To do this, two modeling programs are used: IDA ICE and EED (Earth Energy Designer). The project focuses on three main parts. Part one is a sensitivity analysis of internal loads and construction specific parameters that shows how a variation in these affects the heating and cooling demands. To accomplish this, several models are created and simulated in IDA ICE. In part two, the long-term ground temperature is studied for two of the models analyzed in part one. This is done in both IDA (through a new borehole module) and EED, followed by a comparison of these results. The last part presents the possible amount of free cooling that can be taken from the ground. This estimation is made through simulations in EED, using altered load profiles of the two previously mentioned models. Additionally, this part covers the effects of a changed borehole configuration (number of boreholes, depth, layout, etc.). The results of the first part (the sensitivity analysis) show that there is a rather large variation in annual heating and cooling demands depending on what approach is used for estimating a reasonable amount of internal loads. One way to do this is to first determine the maximum possible load in each zone and then, when simulating the annual energy demand, reduce the total load in the whole building by a certain factor. Another approach is to, from the start of the building modeling, more accurately try to estimate the average amount of internal loads in each zone. In the second part, due to unbalanced load profiles for both analyzed models, the temperature of the borehole storage will increase over time if there is no limitation of the amount of cooling taken from the ground. The results of IDA generally agree with those of EED. In the last part of the project it is shown that a thermally more favorable borehole installation could increase the relative amount of free cooling from the ground, compared to the current installation.

Requirements regarding efficient energy use and reduction in CO2 emissions are becoming increasingly strict. The building sector accounts for a large part of CO2 emissions and the potential for reductions within this sector should be considerable.This thesis is a continuation of the author's project thesis. The main focus is to improve the earlier model emphasizing the modeling of the interactions between the leisure home building and the ground. The goal is to develop a prototype of a leisure home where sanitary installations are kept frost proof throughout the year without the use of primary energy sources or electricity, minimizing net CO2 emissions. The building envelope is constructed of poorly insulated log walls. The sanitary installations are placed in a thermally insulated internal zone, and an active solar heating system is developed to transfer heat into the ground in this internal zone. The intention is to store the heat, transferred to the internal zone during sunny periods, in a thermal mass under the cabin. This would then passively arise during cold periods, maintaining frost proof conditions. The leisure home is planned to be located in the southern mountain regions of Norway. Different simulation tools were considered for modeling the leisure home and its energy system. The dynamic simulation tool ESP-r was chosen, and an improved model from the project thesis was developed. Different methods and theories concerning how the solar heating system and the ground could be modeled have been studied. The interactions between the building and the ground were modeled by implementing a new basement zone for the leisure home, and defining a BASESIMP configuration as boundary conditions for the surfaces adjacent to the ground. BASESIMP performs quasi 3-dimensional calculations for the heat transfer between the building and the ground. Since the heat storage is not taken into account in the BASESIMP configuration, the storage is represented in the ground construction; the basement floor of the inner zone. The solar heating system is represented in a control loop. The control loop injects electric heat into the basement floor for a given period each day. The electric data is based on solar radiation data, and the time intervals for when heat is injected into the floor are determined from when solar radiation is available in the day. Climate data from Östersund, Sweden has been used as an approximation as there was no available climate file for the southern mountain regions of Norway. Different system parameters have been changed to investigate the influence they have on the temperature conditions in the internal zones throughout the year. The internal zones maintain much more stable temperatures throughout the year than the outer zones. This shows that isolating the frost proof zones in the leisure home, represent a major advantage in the design process. The ground construction in the basement floor of the inner zone has been modeled as a thermal mass with high density and high specific heat capacity. This dense thermal mass is modeled to account for the whole area under the cabin. A south facing solar collector with an area of 4 m2 and an inclination of 70 ° indicates that the temperature in the internal zones stays above 4.2 °C throughout the year, subject to the given ground conditions and without collecting heat during May until August. The delivered energy to the ground construction in the basement floor of the inner zone for a year under the given conditions and with a collector efficiency of 45 % turned out to be 878 kWh.Heat transfer from the ground into the internal zone turned out to have a significant heat contribution in cold periods. Results also showed a noticeable potential for seasonal storage of the energy extracted from the solar heating system.For further studies, the interactions between the heat storage and the surrounding ground should be studied in a 3-dimensional conduction program. Insulation regarding snow should also be implemented in a future model to study the effect of extra insulation on the ground surface.

Pile heat exchangers are expected to make a significant contribution to meeting UK and EU renewable energy and carbon dioxide reduction targets. However, design for the thermal capacity of pile heat exchangers has to date been largely based on methods developed for borehole heat exchangers. Piles have a much smaller aspect (length to diameter) ratio than boreholes and consequently their thermal behaviour is different in a number of important ways. This thesis explores these differences and makes recommendations for improved assessment of pile heat exchanger thermal capacity. Traditionally vertical heat exchanger design assumes separation of the thermal effects in the ground and in the pile. A transient temperature response function is used to assess temperature changes in the ground and a steady state resistance is applied to the pile concrete. In this thesis existing approaches to temperature response functions are critically assessed for use with thermal piles. It is important to take into account the larger pile diameter, which causes increased temperature changes in the short term. In the long term, the shorter pile length will result in reduced temperature changes as steady state is reached more quickly. Simple 2D numerical modelling has been carried out and the results used to derive a new method for determining pile thermal resistance. However, for large diameter piles, the time taken for the pile to reach steady state suggests that the use of a constant thermal resistance in design is not always appropriate. In these cases it is recommended that a transient temperature response function is used to assess the response of the ground and the concrete together. The applicability of short duration thermal response testing for pile heat exchangers has been examined. Modelling and case study data has shown that the technique is only reliable for piles of 300mm diameter or less. For the special case of large diameter piles with centrally placed heat transfer pipes then it is possible to use the test to determine the thermal conductivity of the pile concrete, but not pile thermal resistance.

There is a large potential in making the residential and service sector more energy efficient and the first step towards achieving a more efficient use of energy is to implement an energy audit. In this study a property with an approximate area of 8 000 m2, consisting of a main building and three building extensions from different eras has been examined. The main building and its extensions were built in different stages and the first one in the early 20th century and some parts of the last building extension were modified at the time that the examination was carried out. This indicates that there is a vast energy savings potential in the property and an energy audit was performed. The main aim of the study was to examine where the energy was being used and where energy could be saved. Energy saving measures has been suggested together with a calculated approximate energy decrease and payback period. The total energy savings potential for the measures is approximately 146 MWh. The energy audit showed that a large amount of electricity was being used during non-work hours and that energy was lost through the building envelope. The electricity use during non-work hours was examined during the night walk, however, it is suggested to carry out further examinations regarding the property’s vast electricity use during non-work hours. To add loose wool in the roof of B2 has an energy savings potential of 33 000 kWh/year. Another measure is to clean the heat exchangers, this measure has an energy savings potential of 26 000 kWh/year. Also it is suggested to optimize the operational hours for the lighting by implementing presence control and to decrease the energy use for ventilation by cleaning the heat exchangers. Further examinations that would improve the study would be to do measurements of the electricity and temperatures to get a better understanding of the buildings energy use. Also to model the building in a simulation tool would give a calculated energy loss that is more like the actual energy loss of the building and make the results more reliable.

Syfte: Syftet med arbetet är att bidra till att fastighetsägare fortsatt ska kunna förvalta, driva och bruka gamla kulturhistoriskt viktiga hus även i framtiden. Metod: De metoder som valts för att uppnå målet är dokumentanalys, litteraturstudier och fallstudie. Resultat: Kulturhistoriskt viktiga byggnader behöver energieffektiviseras för att de ska kunna hållas i bruk och existera. Det går att genomföra energieffektiviserande åtgärder utan att skada byggnadens kulturvärde. Åtgärder som fönsterbyte, tilläggsisolering och byte av ventilationssystem bör väljas beroende på husets karaktär. Tilläggsisolering och fönsterbyte är effektiva åtgärder för att minska energiförbrukningen av gamla kulturhistoriskt viktiga byggnader, men riskerar ofta att förvanska byggnadens karaktär. Ventilationssystemsbyte kan innebära mindre ändringar av byggnaden men är en relativt dyr investering. Konsekvenser: Ändringar i en befintlig byggnad kommer dock alltid att påverka dess konstruktion, men det betyder inte att byggnadens kulturhistoriska värde förvanskas. Begränsningar: Beräkningar kommer endast att utföras för ett referensobjekt, stadsbibliotek i Tidaholm. Det beräknade resultatet kommer vara specifikt för denna byggnad, eftersom resultatet varierar med byggnaders olika egenskaper. Däremot kan lösningarna tillämpas på flera objekt. Det finns flera olika energieffektiviserande åtgärder men i denna rapport utreds tilläggsisolering, fönsterbyte och ventilationsbyte. Nyckelord: Energieffektivisering, kulturhistoriskt viktiga byggnader, värmeväxlare, Boverkets byggregler, ventilation.
Purpose: The purpose of the work is to help municipalities continue to manage, operate and use old historic houses in the future. Method: The methods chosen to achieve the objective is document analysis, literature studies and case study. Findings: Culture heritage buildings needs to get more energy efficient, so they can be kept in use and existence. It is possible to implement energy efficiency measures without damaging the building's cultural value. Measures like window replacement, insulation and replacement of ventilation systems should be selected depending on the character of the house. Insulation and window replacement are effective measures to reduce the energy consumption of old historically important buildings, but often risk distorting the character of the building. Ventilation system replacement can involve minor changes to the building but is a relatively expensive investment. Implications: Changes in an existing building will always affect its construction, but it does not mean that the building's heritage value is distorted. Limitations: Calculations will only be performed for a reference object, library in Tidaholm. The calculated result will be specific for this building, since the outcome varies with buildings and their different characteristics. However, the solutions can be applied to multiple objects. There are several energy efficiency measures, but this report will only involve insulation, window replacement and ventilation changes. Keywords: Energy efficiency, historically important buildings, heat exchanger, building regulations, ventilation.

In the last years smart buildings topic has received much attention as well as Building Information Modelling (BIM) and interoperability as independent fields. Linking these topics is an essential research target to help designers and stakeholders to run processes more efficiently. Working on a smart building requires the use of Innovation and Communication Technology (ICT) to optimize design, construction and management. In these terms, several technologies such as sensors for remote monitoring and control, building equipment, management software, etc. are available in the market. As BIM provides an enormous amount of information in its database and theoretically it is able to work with all kind of data sources using interoperability, it is essential to define standards for both data contents and format exchange. In this way, a possibility to align research activity with Horizon 2020 is the investigation of energy saving using ICT. Unfortunately, comparing the Architecture Engineering and Construction (AEC) Industry with other sectors it is clear how in the building field advanced information technology applications have not been adopted yet. However in the last years, the adoption of new methods for the data management has been investigated by many researchers. So, basing on the above considerations, the main purpose of this thesis is investigate the use of BIM methodology relating to existing buildings concerning on three main topics: • Smart data management for architectural heritage preservation; • District data management for energy reduction; • The maintenance of highrises. For these reasons, data management acquires a very important value relating to the optimization of the building process and it is considered the most important goal for this research. Taking into account different kinds of architectural heritage, the attention is focused on the existing and historical buildings that usually have characterized by several constraints. Starting from data collection, a BIM model was developed and customized in function of its objectives, and providing information for different simulation tests. Finally, data visualization was investigated through the Virtual Reality(VR) and Augmented Reality (AR). Certainly, the creation of a 3D parametric model implies that data is organized according to the use of individual users that are involved in the building process. This means that each 3D model can be developed with different Levels of Detail/Development (LODs) basing on the goal of the data source. Along this thesis the importance of LODs is taken into account related to the kind of information filled in a BIM model. In fact, basing on the objectives of each project a BIM model can be developed in a different way to facilitate the querying data for the simulations tests. The three topics were compared considering each step of the building process workflow, highlighting the main differences, evaluating the strengths and weaknesses of BIM methodology. In these terms, the importance to set a BIM template before the modelling step was pointed out, because it provides the possibility to manage information in order to be collected and extracted for different purposes and by specific users. Moreover, basing on the results obtained in terms of the 3D parametric model and in terms of process, a proper BIM maturity level was determined for each topic. Finally, the value of interoperability was arisen from these tests considering that it provided the opportunity to develop a framework for collaboration, involving all parties of the building industry.

This study aims to rationalize the consumption of thermal energy in residential buildings by recovering heat from wastewater inside the building before entering the central sewage network outside the building, by conducting an analytical study for a residential tower in Syria to find out the coverage percentage of the heat energy recovered from wastewater for the heating and domestic hot water loads needed for the tower, and calculating the percentage of reduction in carbon dioxide (CO2) gases. It is a simple technology as the thermal recovery system consists of three main components, which are in order: a wastewater tank, heat exchangers, and a heat pump. The research begins with an introduction that consists of the importance of wastewater and the waste heat energy it carries. After that, there are some case studies, research problem, its importance, the aim of the research, and finally the research methodology. In the first chapter, we talked about the concept of heat recovery from wastewater in general, methods of heat recovery, and the most important advantages and disadvantages of this process. It also includes an identification of the main parts used in this technology and how it works, especially the exchangers and the heat pump. This chapter also addresses the problem of forming a layer of biofilms on the surface of heat exchangers from the wastewater side and the most important methods used to treat it. We move on to the second chapter, in which we review the most important facilities for heat recovery from wastewater that have been viewed. Then comes the third chapter in which the heat recovery process was conducted for a nine storey residential tower in Syria, each floor has four apartments, where we first calculated the rate of wastewater flow for the entire tower, and we proposed a heat recovery system (physical model) inside the tower. Then the mathematical equations for heat recovery and the solution of these equations were developed based on some necessary assumptions needed in the solution process to know the most important results desired in this field. It also included the calculation of the coverage ratio of the heat energy recovered from the wastewater for the domestic hot water and heating loads, as well as the calculation of the mass and percentage of the reduction of carbon emitted to the atmosphere. Then simple economic feasibility was also conducted in this chapter to know the daily financial savings as a result of using this technology. The research ends with the most important conclusions and future research that have been reached and the conclusion of the research. The most important results show that the average coverage percentage of heat energy recovered from wastewater for heating load in residential buildings ranges between [30-56%]. It was also found that the average coverage percentage of heat energy recovered from wastewater for domestic hot water load ranges between [65-100%].

There is global effort to reduce the emission of greenhouse gases that causes global climate change, of which significant percentage is related to buildings. Uses of passive and low-energy strategies for indoor thermal environmental control are being explored by researchers to reduce the operational energy consumption in bUildings. One of these options is the use of thermal mass of the ground as a heat source or heat sink for cooling and heating of indoor spaces in bUildings. Earth-air heat exchanger (EAHX) is a subterranean ventilation system that can be used to pre-coollpre-heat building ventilation air supply. Due to the ground's thermal mass, the daily fluctuation of ambient extremes is dampened with increasing depth below the ground surface. Therefore soil temperature at 1 m depth and below is always lower than ambient temperature in summer and higher than ambient temperature in winter. The application of EAHX and knowledge of their performance is scarce under UK climatic and soil conditions. This research therefore aims to evaluate the potential of using EAHX in the UK for cooling buildings in summer. Critical literature review has been undertaken on the performance of EAHX in different climatic conditions and the various approaches to the thermal analysis of EAHX. It reveals that the system has potential for building cooling applications in a variety of conditions. A standalone simulation tool has been developed using the Transient System Simulation Environment (TRNSYS). Building models using different mechanical ventilation strategy have also been developed to enable integrated evaluation of the performance of EAHX on indoor thermal comfort conditions and building cooling loads. Data of climatic and soil parameters required for the thermal analysis of EAHX have been determined for different regions in the UK. Integrated thermal simulations of EAHX system have been conducted using the developed building models and the determined soil and climate conditions. Monitoring data from an existing project incorporating EAHX have been analysed and results have been discussed. Parametric study of EAHX has been carried out for three locations, representing the regional climate span of the UK, in order to evaluate the range of thermal performance of the system. Data of various performance indicators have been established to provide the necessary information for the evaluation of the system potential in different locations. This research has established the thermal performance and the characteristics of the important parameters for the design of EAHX system in the UK. The outcomes are significant in contributing to a better understanding of the system's thermal behaviour and in predicting the thermal performance for building cooling application. As a future work, based upon the data generated by this research, there is a need to develop a full database of the performance data for different configurations of EAHX and at different locations around the country. There is also a need for integrated design tool to evaluate the dynamic thermal performance of EAHX system when integrated with other ventilation strategies.

Heating, Ventilating and Air Conditioning Systems (HVAC) are not only one of the most energy consuming components in buildings but also contribute to green house gas emissions. As a result often environmental design strategies are focused on the performance of these systems. New HVAC technologies such as Geothermal Heat Pump systems have relatively high performance efficiencies when compared to typical systems and therefore could be part of whole-building performance design strategies.

In collaboration with the Virginia Tech Corporate Research Center, Inc., this research studies the energy consumption and cost benefits of the Geothermal Heat Pump System that has been integrated and operated in the KnowledgeWorks I and II buildings located on the Virginia Tech campus.

The purpose of this thesis is to understand the energy and cost benefits of the Geothermal Heat Pumps System when compared to the conventional package variable air volume (VAV) with hot water coil heating and air-source heat pump systems using computer simulation and statistical models. The quantitative methods of building energy performance and life-cycle cost analyses are applied to evaluate the results of simulation models, the in-situ monitoring data, and the associated documents. This understanding can be expanded to the higher level of architectural systems integration.
Master of Science

This diploma thesis is focused on nearly zero energy buildings, which are a mandatory part of construction of the buildings in Czech republic after 2020. It also deals with HVAC and its design as part of these buildings. The theoretical part deals with legal and technical regulations and possible savings in HVAC systems. The computational part is focused on two solution of HVAC systems in given object. The project part is about the given object, which is otevřená zahrada Brno. This building was founded by Nadace Partnerství s.r.o.. This third part of diploma thesis deals with the quality of indoor microclimate and evaluation of the heat recovery system effiency, which is applied in local HVAC unit.

Baigiamajame magistro darbe nagrinėjamos grunto ir atliekinės pastato šilumos panaudojimo galimybės mažaenergiame pastate, Vilniaus mieste, Lietuvoje. Suskaičiuoti keturi pastato energijos balansų variantai, naudojant ”CASAnova” kompiuterinę skaičiavimo programą, su skirtingais atitvarų šilumos perdavimo koeficientais. Pastate taikomos dvi energijos taupymo priemonės. Pirmoji yra gruntinis šilumokaitis naudojamas šviežio oro pirminiam pašildymui mechaninio vėdinimo sistemoje, kurio skaičiavimai atliekami ”GAEA” programa. Antroji yra nuotekų šilumos atgavimo šilumokaitis, naudojamas į pastatą tiekiamo šalto vandens pirminiam pašildymui, atgaunant dalį šilumos iš duše susidariusių nuotekų. Pastatui reikiamas metinis šilumos ir vėsos energijos kiekis gaminamas šilumos siurbliu su vertikaliu gręžiniu grunte, kurio skaičiavimams naudojama ”EED” programa. Gręžinių gyliai yra suskaičiuoti kiekvienam pastato energijos balansų variantui. Atlikti ekonominiai skaičiavimai rodo gruntinio ir nuotekų šilumos atgavimo šilumokaičių įdiegimo pastate ekonominę naudą. Pateikti rezultatai rodo kiekvieno varianto energijos poreikius ir gręžinio grunte gylį priklausomai nuo pastato varianto atitvarų šiluminių savybių bei taikomų energijos taupymo sprendimų. Darbą sudaro 9 dalys: įvadas, 6 skyriai, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis – 64 psl. teksto, 41 paveikslai, 14 lentelės, 31 bibliografinis šaltinis.
The final master thesis presents technical analysis of low-energy residential building in Vilnius, Lithuania. Building has low temperature floor heating, mechanical ventilation with heat recovery unit and hot water preparation with buffer tank systems. Using “CASAnova” software is calculated fourth energy balances of building according fourth different heat transfer coefficients of the walls. All heating and cooling energy demand of a building is generated from the ground. It is made by using a heat pump with single borehole. A calculation of borehole sizing is made with “EED” software. Two energy saving technologies are analysed for a building. The first idea is to reduce heat energy consumption of hot water preparation. There is calculated benefit of waste water heat recovery heat exchanger which function is to pre-heat hot water using waste water from the shower. Second idea is to reduce heat energy consumption for fresh air heating in air handling unit. There is calculated benefit of earth-to-air heat exchanger using “GAEA” software. Final result of all calculations shows influence of heat transfer coefficient and energy saving technologies to building annual energy balance and depth of borehole. Economic benefit of using energy saving technologies is calculated. Structure: introduction, 6 chapters, conclusions and suggestions, references. Thesis consists of 64 p. of text, 41 figures, 14 tables and 31 bibliographical entries.

The diploma thesis is elaboration of project documentation of the object Housing for seniors in Brno - Dolní Heršpice. The site is located un the area with the planned development of the city. The object is detached, three-story with a partial basement. The building is divided into five parts. The building is based on concrete foundation pads and strips. The structural construction is a combined column and wall system in technological design as monolithic concrete. The building is designed as a low energy building, with contact insulation (ETICS). The whole building is designed with forced air exchange. An extensive and intensive walkable flat roof is designed. The aim is to create small, barrier-free, community housing with affordable services and support, with a possible life expectancy. Services for the elderly with reduced self-sufficiency and with mild health and mental dysfunctions are considered. The building is equipped with space for accommodation with a capacity of 48 beds, space for eating with a separate kitchen, space for leisure and physical activities, space for basic health and social care and space for administrative and technical facilities. The construction is divided into several buildings, the subject of the thesis is primarily the solution SO.01 - Housing for seniors

För att tillgodose den studerande KTH byggnadens framtida krav kommer det befintliga ventilationssystemet att bytas ut. Två olika möjliga värmeåtervinningssystem har jämförts ur fjärrvärmebehovssynpunkt. Det befintliga systemet med vattenburen batterivärmeväxlare har en låg värmeåtervinningsgrad och Akademiska Hus önskar system med högre värmeåtervinning. I byggnaden har roterande värmeväxlare och frånluftsvärmepump för uppvärmning av tilluften jämförts. Då värmeåtervinning från dessa system inte är tillräckligt kommer fjärrvärme att används. I beräkningarna jämförs fem roterande värmeväxlare mot varierande antal frånluftsvärmepumpen. Genom detta fås varierande resultat och fjärrvärmebehovet ökar/minskar ju färre/fler värmepumpar som tas med i beräkningarna. Frånluftsvärmepumparna antas både vara konstanta och ”nedtrappande”. Vid de konstanta antal frånluftsvärmepumparna visar resultaten att, vid maximal personbelastning, är fjärrvärmebehovet för fem roterande värmeväxlare lägre än vid användning av fem (eller färre) frånluftsvärmepumpar. Vid sannolik personbelastning är fjärrvärmebehovet för fem roterande värmeväxlare lägre än vid användning av två (eller färre) frånluftsvärmepumpar. Vid de ”nedtrappande” antalen frånluftsvärmepumpar är fjärrvärmebehovet med roterande värmeväxlare lägre både vid maximal och också sannolik personnärvaro. Vid val av system har aggregat för fastighets- och lokalbyggnader jämförts då flödena är höga. I slutssats kan val av tillverkare för respektive system påverka fjärrvärmebehovet.
To meet the renovated KTH building’s future requirements, the existing ventilation system will be replaced. Two different possible heat recovery systems have been compared in regards of district heating. The existing system of water coil heat exchanger has low heat recovery efficiency and Akademiska Hus wishes for a system with higher heat recovery. A rotating heat exchanger and exhaust air heat pump have been compared in regards of heating the supply air. At times when heat recoveries from these systems are not sufficient, the district heating will be in use. In the calculations five rotating heat exchangers and varying number of exhaust air heat pumps have been compared. Through this varying results will occur and the district heating demand will increase/decrease the fewer/more pumps that are taken into account. The exhaust air heat pumps are assumed to be both constant and down going. At the constant use of exhaust air heat pumps the results show that (when in maximum occupancy) the district heating demand with five rotating heat exchangers is lower than when using the five (or fewer) exhaust air heat pumps. During probable occupancy the district heating demand with five rotating heat exchangers is lower than when using two (or fewer) exhaust air heat pumps. The district heating demand is lower when using rotating heat exchangers than the “down going” numbers of exhaust air heat pumps. Only office- and apartment building acquired heating systems have been compared due to the high air flows. The selection of manufacturer of these systems may affect the district heating demand.

The theme of this master's thesis is the elaborating of an energy audit according to the valid legislation in the Czech Republic a five-storey apartment building. The master's thesis consists of three main parts. Theoretical, Computional and Energy Audit. The theoretical part focuses on the theme of solar thermal collectors. In the calculation part, the energy consumption of the assessed object is analyzed in both the initial and the new state. The energy audit is drawn up in accordance the Decree number 480/2012 Sb. in the current version.

Purpose: This degree project aims to see how the energy demand from active heating of detached houses can be improved to meet the energy performance requirements set for nearly zero-energy buildings by Boverket (The Swedish National Board of Housing, Building and Planning). Method: To accomplish this, the benefits from two different energy-saving installations are studied: bedrock heat pumps and heat exchangers in Heat Recovery Ventilation Systems (HRV-systems). These are then compared in a new and an older detached house with very different heat losses. There are several reports of energy-saving systems in detached houses. What distinguishes this work is that it compares the specific results from the added energy-saving system depending on whether it was added first or last. The older detached house is an important part of this work as it represents a possible impact on parts of the existing housing stock with a similar technical standard. The energy balance for the buildings is calculated monthly with all contributions from passive heat considered, and with the energy demand for active heating as the main result. Results: It is very difficult to meet the energy performance requirements for an older detached house without extensive measures or renovations. The HRV-system had a low to very low impact. Both types of detached houses have a lot to gain from an investment in bedrock heating, especially the older one that has high energy demands. However, the new detached house with a higher technical standard in the building envelope, was the only one to meet the energy requirements with the bedrock heat pump on its own. Conclusion: Bedrock heating can be a very profitable investment as it provides heat both for the active heating of the building as well as for the domestic hot water. In order to meet tougher energy requirements, the bedrock heat pump may need to be accompanied by an improved and more energy-efficient building envelope and the supply of self-produced electricity, such as solar cells. HRV-systems require a good air tightness and an energy-efficient building envelope to be profitable. In older detached houses, it is not a profitable investment, as it does not have sufficiently large proportions of controlled ventilation to work with. In newer houses the proportion of controlled ventilation is bigger, but the amount of heat loss that can be affected is still not as big as the energy savings a bedrock heat pump can bring.

Le travail réalisé dans le cadre de cette thèse porte sur l'effet que les bâtiments exercent sur l'atmosphère urbaine et notamment sur les échanges énergétiques qui s'opèrent entre les deux systèmes. Afin de modéliser plus finement les effets thermiques du bâtiment sur les écoulements atmosphériques lors de simulations réalisées par le logiciel de CFD Code_Saturne, nous procédons au couplage de cet outil avec le modèle de bâtiment BuildSysPro. Cette bibliothèque fonctionne sous Dymola et peut calculer des matrices descriptives du bâtiment utilisables ensuite en dehors du logiciel. Ce sont donc ces matrices qui sont utilisées pour le couplage par l'intermédiaire d'un code assurant l'échange de données entre les calculs de thermique du bâtiment et ceux de CFD. Après une revue des phénomènes physiques en lien avec l'atmosphère urbaine et des modèles existants, nous nous intéressons aux interactions entre l'atmosphère et le milieu urbain, notamment les bâtiments. Ceux-ci peuvent avoir un impact sur les écoulements aussi bien dynamique, en tant qu'obstacles, que thermique, via leurs températures de parois. Parallèlement à la mise en place du couplage entre les deux logiciels, nous étudions les données de la campagne de mesures EM2PAU que nous utilisons pour notre validation. EM2PAU, réalisée en 2011 à Nantes, représente une rue canyon idéalisée par deux rangées de conteneurs. La campagne a pour spécificité de prendre simultanément les mesures de températures d'air et de parois ainsi que les vitesses du vent de référence et des écoulements dans le canyon par un anémomètre sonique placé à 10 m d'altitude et six autres positionnés en six emplacements dans le canyon. Nous cherchons donc à mettre en évidence les effets dynamiques et thermiques des bâtiments sur les écoulements à partir des résultats de cette campagne, pour ensuite les simuler. Puis la modélisation numérique des écoulements sur le domaine de EM2PAU est réalisée. L'objectif de ce travail est de mettre en évidence l'influence des effets thermiques des parois sur les flux atmosphériques. Nous comparons des simulations avec différentes méthodes pour donner les valeurs des températures de surface des conteneurs. La première méthode consiste à imposer ces températures d'après les mesures ; ainsi la température de chaque paroi sera fixée à la température de surface mesurée lors de l'instrumentation de EM2PAU. Quant à la deuxième méthode, on impose la température de l'air extérieur mesurée à l'instant simulé à toutes les parois des conteneurs, afin de créer un cas où l'on n'observe que peu ou pas d'échanges de chaleur. Enfin la troisième méthode est la simulation couplée de Code_Saturne et BuildSysPro. Les résultats des différentes simulations sont alors comparés afin de distinguer les effets thermiques des parois des bâtiments sur les écoulements d'air. Nous observons que les effets dynamiques sont primordiaux et peuvent engendrer des vitesses verticales de l'écoulement dans le canyon de l'ordre plusieurs mètres par seconde, tandis que des écarts de températures de surface de l'ordre de 15°C peuvent modifier les vitesses verticales du vent de moins de 0, 5 mètres par seconde. Si ces effets thermiques sont difficiles à isoler sur des mesures en raison des autres phénomènes susceptibles d'influencer les écoulements atmosphériques, les études numériques peuvent toutefois mieux quantifier ces différences
This thesis work is about the effect of buildings on the urban atmosphere and more precisely the energetic exchanges that take place between these two systems. In order to model more finely the thermal effects of buildings on the atmospheric flows in simulations run under the CFD software Code_Saturne, we proceed to couple this tool with the building model BuildSysPro. This library is run under Dymola and can generate matrices describing the building thermal properties that can be used outside this software. In order to carry out the coupling, we use these matrices in a code that allows the building thermal calculations and the CFD to exchange their results. After a review about the physical phenomena and the existing models, we explain the interactions between the atmosphere and the urban elements, especially buildings. The latter can impact the air flows dynamically, as they act as obstacles, and thermally, through their surface temperatures. At first, we analyse the data obtained from the measurement campaign EM2PAU that we use in order to validate the coupled model. EM2PAU was carried out in Nantes in 2011 and represents a canyon street with two rows of four containers. Its distinctive feature lies in the simultaneous measurements of the air and wall temperatures as well as the wind speeds with anemometers located on a 10 m-high mast for the reference wind and on six locations in the canyon. This aims for studying the thermal influence of buildings on the air flows. Then the numerical simulations of the air flows in EM2PAU is carried out with different methods that allow us to calculate or impose the surface temperature we use, for each of the container walls. The first method consists in imposing their temperatures from the measurements. For each wall, we set the temperature to the surface temperature that was measured during the EM2PAU campaign. The second method involves imposing the outdoor air temperature that was measured at a given time to all the surfaces, reducing every heat exchange to almost zero. The third method at last is the coupled simulation of Code_Saturne and BuildSysPro where BuildSysPro calculates the wall temperature from the Code_Saturne data. . The results of these different ways of modelling the wall temperatures are then compared in order to show the thermal effects of building wall heating on the air flows. We notice that the dynamic effects are dominant and can generate vertical wind speed that can pass several meters per second. On the other hand, differences of surface temperatures higher than 15°C can influence the vertical wind speed for less than 0.5 meters per second. These thermal effects are not easily highlighted with measured data because of the other phenomena that can impact the air flows. However they can be quantified with numerical studies

Kompaktaggregat är ett integrerat FTX- och FVP-system som används i passivhus. Vi har gjort

energiberäkningar i programmet VIP+ för att se hur kompaktaggregatet skulle kunna fungera i

passivhus i Sverige.

De resultat vi har fått fram ur VIP+ visar att passivhus med ett installerat kompaktaggregat klarar

av att nå passivhuskraven ända upp till Skellefteå. De beräknade värdena understiger kraven för

passivhus, men en viss marginal behövs för att kraven ska nås även efter uppförandet av

byggnaden. Vi har även tolkat tekniska uppgifter på ett sätt som enligt oss har en positiv effekt

för passivhus på kallare orter. Därför tror vi inte att värdena för de tre nordligaste platserna är

helt tillförlitliga. De övriga plasterna ser bra ut. Passivhus med ett installerat kompaktaggregat

klarar enligt oss passivhuskraven i dessa städer; Malmö, Växjö, Göteborg, Stockholm och med

tveksamhet Borlänge.

Compact units are an integrated balanced ventilation whit recovery and an extracted air heat

pump that are used in passive houses. We have done some energy calculations to see how

compact units would be able to operate in Sweden.

The results we have been receiving from VIP+, display that a passive house with an installed

compact unit manages to achieve the demands for passive houses all the way up to the city

Skellefteå. The calculated values are below the demands for passive house, but a certain margin

is needed for the demands to be met after the building is complete. We have also construed

technical data in a way that can have a positive effect on the passive houses in colder locations.

Because of this we do not think the values for the three cities furthest north are entirely reliable.

The other locations look good. Passive houses with an installed compact unit would, according

to our research meet the passive house demands in these cities; Malmö, Växjö, Göteborg,

Stockholm and with a doubt Borlänge.

Diploma thesis is focus on ventilation systems in Zero energy building and indoor air quality. Whole thesis has three part. First is about theory, where you can find law regulations and standards connected wit nZEB, factors influence IAQ and introduced ventilations systems. Second part is focus on particles transport in buildings like a nZEB and in heat recovery units. Last part of the thesis shows own design of the nZEB for Nový Lískovec.

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

Dans le contexte énergétique français actuel, deux principaux enjeux émergent. À court terme, des pointes de consommation électrique croissantes sont observées les dernières années pendant la période hivernale. Ces pointes sont fortement liées au chauffage électrique et ont des conséquences économiques, environnementales et sociales importantes. Dans un long terme, des objectifs environnementaux ambitieux ont été fixés au niveau national et européen, nécessitant la technologie de stockage thermique et une gestion efficace de l'environnement bâti. Les Matériaux à Changement de Phase (MCP) ainsi que les dispositifs de type échangeurs thermiques offrent des résultats promettant grâce au stockage thermique et le déplacement des consommations. Dans ce cadre, l’objectif de cette thèse est de développer des solutions de déplacement des consommations énergétiques qui prennent en compte le confort thermique des occupants et la qualité de l’air intérieur. Pour ce faire, deux outils sont nécessaires: un échangeur thermique expérimental (prototype) et un modèle numérique capable de simuler son comportement. L'échangeur contient du MCP macroencapsulé (paraffine) et est conçu de manière à faciliter son intégration dans un système de ventilation. Il a comme but de décaler la consommation due au chauffage électrique vers la période hors pointe. Le dispositif a été caractérisé expérimentalement lors des cycles thermiques complets (charge et décharge) en utilisant une quantité importante de capteurs. Il a ensuite été couplé à une cellule expérimentale, afin de tester des stratégies de contrôle préliminaires. Le modèle numérique est basé sur la discrétisation spatiale et l’établissement du bilan de chaleur des couches considérées, la méthode de la capacité thermique apparente, ainsi que l’utilisation des différences finies. Après validation à l’aide des données expérimentales, le modèle a été utilisé pour optimiser la performance de l'échangeur. Plusieurs paramètres ont été étudiés, y compris les dimensions de l'échangeur, la quantité et les propriétés du MCP, en cherchant la configuration avec le compromis optimal entre la chaleur emmagasinée et le temps nécessaire pour la charge et la décharge. Le modèle numérique a été couplé à un modèle de simulation du bâtiment et un logement de 80m2 a été conçu pour la mise en oeuvre et l'évaluation des stratégies de contrôle, en investiguant différents scénarios sur une période hivernal d’un mois. Les scénarios varient avec une complexité croissante, d'abord en considérant l’effacement énergétique et le confort thermique, ensuite en ajoutant le prix final de la consommation électrique et enfin en prenant compte la qualité de l'air intérieur avec la présence d'une famille de quatre personnes. 6 Cette étude a été menée dans le cadre d'un projet financé par l'Agence National de la Recherche (Stock-Air: ANR-Stock-E) et a également été soutenu par le ministère de l'Ecologie, du Développement durable et de l'Energie
Considering the current French energy context, two major challenges are emerging. In the short term, significant peak power consumption has been observed in the past few years during the winter season. These peaks are strongly linked to electrical space heating and have important economic, environmental and social implications. In the long term, ambitious environmental goals have been set at national and European levels, requiring thermal storage technology and efficient management of the built environment. As part of the solution, Phase Change Materials (PCM) and heat exchanger applications offer promising results through thermal storage and load shifting techniques. Within this framework, the objective of this thesis is to develop load shifting solutions which also take into account the thermal comfort of the occupants and the indoor air quality. To achieve this, two tools were necessary: an experimental heat exchanger unit (prototype) and a numerical model that accurately simulates its behavior. The exchanger contains macroencapsumated PCM (paraffin) and is conceived in a way that facilitates its integration in a ventilation system. It is aimed to shift space heating electrical consumption from peak to off-peak period. The unit was experimentally characterized, using an important amount of sensors through full thermal cycles (charging and discharging) and was coupled to an experimental test cell, which led to the testing of preliminary control strategies. The numerical model is based on the heat balance approach and the apparent heat capacity method, using finite differences for differential equation solution under Matlab/Simulink environment. After validation with experimental data, the model was used to optimize the performance of the exchanger. Several parameters were investigated, including heat exchanger dimensions, PCM quantity and properties, seeking the configuration with the optimal compromise between stored heat and the time needed for the charging / discharging process. The numerical model was coupled to a building simulation model and an 80m2 dwelling was conceived for control strategies implementation and evaluation, by investigating different scenarios over a one- month winter period. The scenarios vary with increasing complexity, first considering load shifting and thermal comfort, then adding the final price of electricity consumption and finally taking into account the indoor air quality with the presence of a four-person family. This study has been conducted within the framework of a project funded by the French National Research Agency (Stock-Air: ANR-Stock-E) and was also financially supported by the French Ministry of Sustainable Development

Ce travail de thèse vise à comprendre et analyser les échanges thermiques qui ont lieu entre un bâtiment et son environnement en présence de parois végétalisées « intensives ». Nous présentons dans ce manuscrit, une démarche numérique et expérimentale sur l’évaluation de l’incidence thermique de ces Murs Végétalisés (MV). Une plateforme constituée de trois prototypes identiques (3 mini-laboratoires thermiques) sous conditions climatiques réelles a été conçue et instrumentée. Dans un premier temps, deux écrans permettant une variation rapide et graduelle des taux de couvertures de 10 à 100% ont été ajoutés devant les prototypes. Ainsi, plusieurs séries de mesures ont été effectuées et des réductions significatives au niveau des températures et des flux de chaleur ont été enregistrées et interprétées. Cette démarche expérimentale avait pour premier objectif de mettre en oeuvre une occultation artificielle et donc maîtrisée. Un premier modèle a été développé sur la base de l’écriture des équations de bilan des échanges thermiques entre la paroi à occultation variable et son environnement climatique. Ce modèle confronté aux résultats fournis par l’expérimentation apermis de valider les approches théoriques au niveau des transferts radiatifs et convectifs. Dans un deuxième temps, le premier modèle qui a été développé dans ce travail a été adapté au cas d’une occultation « réelle » par de la végétation (lierre ou vigne vierge) puis validé expérimentalement. Il a été finalement implémenté dans un code de simulation thermique dynamique de bâtiment (TRNSYS), et ainsi l’incidence thermique des murs végétalisés simples (intensifs) a pu être évaluée à l’échelle réelle d’un bâtiment. Les résultats de simulations pour un climat tempéré montrent que la présence des plantes à feuilles persistantes a un impact négatif sur la demande énergétique hivernale. A l’inverse, en période estivale, les résultats montrent que les murs végétalisés ont un intérêt au niveau de la limitation des surchauffes. Leur présence réduit alors notablement la consommation énergétique nécessaire pour « climatiser » le bâtiment et améliore ainsi le confort thermique intérieur
This PhD thesis aims to understand and analyse the heat exchanges that occur between a building and its environment in the presence of intensive vegetated walls. In this manuscript, a numerical and experimental approach to evaluate the thermal impact of green walls is presented. A platform composed of three identical prototypes (3 thermal mini-laboratories) under real weather conditions has been designed and instrumented. As a first step, two screens permitting a rapid and gradual variation of coverage rate from 10 to 100% were added to the prototypes. Thus, several series of measurements were performed and significant reductions in temperature and heat flow were recorded and interpreted. The primary objective of this experimental approach was to implement an artificial shading and thus controlled. A first model was developed based on the writing of heat exchanges energy balance equations between the wall with variable coverage rate and its climatic environment. This model confronted to the experimental results allowed the validation of the theoreticalapproaches at the level of radiative and convective heat transfer. Secondly, the first model that was developed in this work has been adapted to the case of a "real" occultation by vegetation (Ivy or Virginia creeper) then validated experimentally.It was finally implemented in a dynamic thermal simulation code (TRNSYS), and thus the thermal impact of green walls were evaluated at the real scale of a building. Simulation results in a temperate climate show that the presence of evergreen plants has a negative impact on winter energy demand. Conversely, in summer, the results show that green walls have an interest in limiting overheating. Their presence significantly reduces energy consumption needed to cool the building and improves the indoor thermal comfort

Le secteur du bâtiment est le premier consommateur d’énergie en France. L’émergence de bâtiments performants apporte une réponse incomplète à ce problème car les comportements des usagers doivent être considérés. Notre objectif est de circonscrire le rôle de facteurs psychosociaux et organisationnels sur l’investissement des salariés pour leur entreprise et pour l’environnement. Au travail, les comportements de citoyenneté organisationnelle (CCO) sont adoptés volontairement et contribuent à l’efficacité de l’entreprise. En prolongement des travaux sur les CCO, les comportements pro-environnementaux (CPE) des salariés peuvent être considérés comme des CCO dirigés vers l’environnement (CCO-E). Pour examiner leurs déterminants, nous avons réalisé six études auprès de 889 étudiants et 592 salariés, travaillant dans un bâtiment classique ou exemplaire. Nous constatons que les salariés se sentant soutenus et traités équitablement seront plus enclins à réaliser des CPE et CCO-E, ce qui incite à renforcer la justice organisationnelle. Par ailleurs, les attitudes, valeurs et habitudes environnementales modèrent les effets du contexte organisationnel sur l’implication des salariés. En outre, la motivation environnementale au travail, lorsqu’elle est autodéterminée, a un effet positif sur les CPE et CCO-E. De même, les normes sociales influencent les comportements des salariés, d’autant plus quand les entreprises présentent une politique environnementale concrète mais non saturante. Enfin, les bâtiments performants offrant un contexte de travail confortable, encouragent la réalisation de CPE et CCO-E par les salariés. À partir de nos résultats, nous proposons des recommandations pour aider les professionnels du bâtiment et les organisations à mieux prendre en compte les occupants
The building sector is the first energy consumer in France. The emergence of efficient buildings provides an incomplete response to this problem because users’ behaviors need be considered. Our aim is to define the role of psychosocial and organizational factors on employees’ investment for their company and for the environment. At work, organizational citizenship behaviors (OCB) are voluntarily adopted and contribute to the efficiency of the company. In continuation of the research on OCB, employees’ pro-environmental behaviors (PEB) can be viewed as OCB directed toward the environment (OCBE). In order to better understand their determinants, we conducted six studies including 889 undergraduate students and 592 employees, working in classic or exemplary buildings. We notice that employees who feel supported and fairly treated by their organization, will be more prone to adopt PEB and OCBE. This result encourages reinforcing organizational justice. Otherwise, environmental attitudes, values and habits moderate the effects of contextual factors on employees’ pro-environmental implication. In addition, self-determined environmental motivation at work has a positive effect on PEB and OCBE. Similarly, social norms have a positive influence on employees’ behaviors, especially when companies make a concrete but not overwhelming environmental policy. Finally, efficient buildings providing a comfortable working environment encourage employees to adopt PEB and OCBE. Based on our results, we propose recommendations to help building professionals and organizations to take better into account the occupants

L'utilisation de systèmes de stockage par chaleur latente constitue une solution permettant l'effacement du chauffage d'un bâtiment résidentiel pendant les périodes de forte demande. Une telle stratégie peut avoir pour objectif le lissage des pics d'appel en puissance du réseau électrique. Cependant, la faible conductivité des matériaux à changement de phase (MCP) qui constituent ces systèmes et le besoin d'une puissance de décharge importante imposent l'utilisation de matériaux dits "architecturés" afin d'optimiser la conductivité équivalente des matériaux stockeurs. Nos travaux s'intéressent plus particulièrement à la méthodologie pour la conception de matériaux pour ces systèmes afin de satisfaire aux exigences de stockage d'énergie et de puissance de restitution. La méthodologie proposée dans ces travaux de thèse est dénommé « Top-down methodology ». Cette méthodologie comporte trois échelles : l'échelle bâtiment (top), l'échelle système et l'échelle matériau (down). L'échelle bâtiment a comme objectif de spécifier le cahier des charges. A l'échelle système, des indicateurs de performance sont définis. Enfin, à l'échelle matériau, l'architecture du matériau solution est proposée. Un outil numérique modélisant le système de stockage par chaleur latente de type échangeur de chaleur air/MCP à été développé pour évaluer les indicateurs de performance. Ce modèle numérique est vérifié avec un cas analytique et validé par comparaison avec des données expérimentales. La méthodologie développée est mise en œuvre dans un deuxième cas d'étude pour le même type de système de stockage. L'analyse du système via les nombres adimensionnels permet d'obtenir des indicateurs de performance du système. A l'issue de cette étape, les propriétés matériaux et fonctionnelles optimales du système sont donc connues. Enfin, un matériau architecturé est alors proposé afin de satisfaire les exigences du système de stockage. Nous montrons alors que par l'intermédiaire d'une plaque sandwich contenant des clous et du MCP les propriétés matériaux nécessaires sont obtenues. De plus, afin de satisfaire aux exigences en termes de propriétés fonctionnelles, le design du système est modifié en ajoutant des ailettes sur les surfaces d'échange. Nous montrons que avec 20 ailettes de 3mm d'épaisseur sur la surface d'échange de la planche à clous, le chauffage est effacé pendant 2h lors de la période de forte demande journalière pendant l'hiver
The use of energy storage systems that exploit latent heat represents a promising solution to erase the heating demand of residential buildings during periods of peak demand. Equipping a building with such components can contribute to the goal of peak shaving in terms of public electricity grid supply. Significant drawbacks, however, are the low thermal conductivity of Phase Change Materials (PCM) that typically constitute such systems,and the requirement for a high rate of discharge. Consequently, the use of so-called architectured materials has been put forward as a means to optimize the effective conductivity of storage materials. Our work is focused upon the development of a methodology to design optimal materials for such systems that meet the criteria of energy storage and energy output. A so-called “top-down metholodogy” was implemented for the present work. This approach includes three scales of interest: building (top), system and material (down). The aim of the building scale analysis is to formulate a set of general design requirements. These are complemented by performance indicators, which are defined at the scale of the system. Finally, at the scale of the material, the architecture of the identified material is elaborated. A numerical simulation tool was developed to determine performance indicators for a latent heat energy storage system comprising of an air/PCM heat exchanger. This model was tested against a benchmark analytical solution and validated though comparison to experimental data. The developed methodology is applied to the specific case of an air/PCM exchanger latent-heat energy storage system. The system is analysed through the study of dimensionless numbers, which provide a set of design indicators for the system. As a result of this stage, the optimal material and functional properties are thus identified. Finally, an architectured material is proposed that would satisfy the design requirements of the storage system. We demonstrate that an arrangement composed of a sandwich of planar layers with nails and PCM can offer the required material properties. Furthermore, in order to meet the desired functional properties, the system design is modified by the addition of fins at the exchange surfaces. With the addition of 20 fins of 3mm thickness attached to the exchange surface of the sandwich panel, the storage system eliminated the heating demand for 2 hours during the period of high daily demand in winter

Ce travail porte sur l'étude et le développement d'un système innovant de ventilation et de chauffage au bois dans les habitations à basse consommation d'énergie, qui sont appelées à devenir la référence constructive en France dès 2015. Dans ces habitations fortement isolées et particulièrement étanches à l'air, les besoins de chauffage sont très faibles et peuvent être couverts par une source de chaleur d'origine renouvelable, telle que le bois énergie. En outre, l'utilisation d'une ventilation performante s'impose comme étant un critère essentiel pour assurer la bonne qualité de l'air intérieur et peut même devenir l'unique vecteur de chauffage en apportant l'appoint de chaleur sur l'air insufflé dans les différentes pièces de l'habitation. Le système présenté dans cette étude propose ainsi de combiner les avantages d'un appareil de chauffage au bois de petite puissance, ici un poêle à granulés de bois, et ceux d'une ventilation à récupération de chaleur sur l'air extrait, grâce à un conduit échangeur intégré à la cheminée du poêle et relié au réseau de soufflage de la ventilation. Développé en partenariat avec l'industriel POUJOULAT, spécialisé dans la fabrication de conduits de cheminée métalliques, ce conduit échangeur permet de récupérer sur l'air neuf une partie de la chaleur initialement perdue par les fumées et de la distribuer dans toutes des zones de vie de l'habitation, même les plus éloignées de l'appareil au bois. Après avoir défini la configuration de couplage à adopter pour assurer le bon fonctionnement de l'ensemble et garantir à la fois la sécurité et le confort des occupants, les performances de plusieurs prototypes de conduit échangeur sont caractérisées expérimentalement. Les résultats obtenus lors des essais en laboratoire permettent alors d'orienter l'évolution des prochains prototypes et de souligner la nécessité de travailler avec un poêle à granulés de bois dont le cycle de combustion est étanche. Un modèle mathématique est également développé pour prédire les performances du dernier prototype de conduit échangeur à triple paroi non isolé sur sa surface extérieure et sa validation est obtenue suite au bon accord entre les résultats calculés et ceux mesurés lors des essais. L'ensemble du système combiné est ensuite installé dans deux habitations à basse consommation d'énergie situées près de Poitiers. L'exploitation des températures et des consommations recueillies pendant la première saison de chauffe montre la bonne tenue du système combiné, ses limites, ainsi que ses conditions d'appropriation par les occupants, dont le comportement apparaît jouer un rôle prédominant dans la réduction des consommations énergétiques.

Liquid desiccant air conditioning (LDAC) has received much attention in recent years. This is mainly because LDAC systems are able to control latent loads in a more energy efficient way than conventional air conditioning systems. Although many research studies have been conducted on LDAC technologies, the following gaps in the scientific literature are addressed in this thesis: (1) carryover of desiccant droplets in air streams, (2) direct comparisons between different configurations of LDAC systems, (3) fundamentals of capacity matching in heat-pump LDAC systems, (4) optimal-control strategies for heat-pump LDAC systems, and (5) importance of transients in evaluating the performance of a LDAC system. Items (1) to (4) are addressed using TRNSYS simulations, and item (5) is addressed using data collected from a field test. The use of liquid-to-air membrane energy exchangers (LAMEEs) as dehumidifiers and regenerators in LDAC systems eliminate the desiccant droplets carryover problem in air streams. This is because LAMEE separate the air and solution streams using semi-permeable membranes, which allow the transfer of heat and moisture but do not allow the transfer of the liquid desiccant. A preliminary configuration for a membrane LDAC system, which uses LAMEEs as the dehumidifier and regenerator, is proposed and investigated under fixed operating conditions in this thesis. The influences of key design and operating parameters on the heat and mass transfer performances of the membrane LDAC system are evaluated. Results show that the membrane LDAC technology is able to effectively remove latent loads in applications that the humidity to be controlled. A comprehensive evaluation is conducted in this thesis for the thermal, economic and environmental performances of several configurations of membrane LDAC systems. The solution cooling load is covered using a cooling heat pump in all systems studied, while the solution heating load is covered using one of the following five different heating systems: (1) a gas boiler, (2) a heating heat pump, (3) a solar thermal system with gas boiler backup, (4) a solar thermal system with heat pump backup, and (5) the condenser of the solution cooling heating pump. Each of the membrane LDAC systems studied is evaluated with/without an energy recovery ventilator (ERV) installed in the air handling system. The influence of operating the ERV under balanced/unbalanced operating conditions is studied. It is found that the most economic membrane LDAC system is the one which uses the evaporator and condenser of the same heat pump to cover the solution cooling and heating loads, respectively (i.e. heat-pump membrane LDAC system). No clear guidance was found in the literature for sizing the evaporator and condenser in a heat-pump LDAC system to simultaneously meet the solution cooling and heating loads. When the heating and cooling provided by the heat pump exactly match the heating and cooling requirements of the solution, the system is “capacity matched”. A parametric study is conducted on a heat-pump membrane LDAC system to identify the influence of key operating and design parameters on achieving capacity matching. It is concluded that the solution inlet temperatures to the dehumidifier and regenerator are the most influential parameters on the moisture removal rate, capacity matching and coefficient of performance (COP). Three control strategies are developed for heat-pump membrane LDAC systems, where these strategies meet the latent loads and achieve one of the following three objectives: (1) meet the sensible loads, (2) achieve capacity matching, or (3) optimize the COP. Results show that the COP of a heat-pump LDAC system can be doubled by selecting the right combination of solution inlet temperatures to the regenerator and dehumidifier. The importance of transients in evaluating the performance of a LDAC system is addressed in the thesis using a data collected from a field test on a solar LDAC system. It is found that the sensible, latent and total cooling energy, and the total primary energy consumption of the LDAC system are changed by less than 10% during an entire test day when transients are considered. Thus, it can be concluded that steady-state models are reliable to evaluate the energy performances of LDAC systems.