Dissertations / Theses on the topic 'Vaccum Insulation Panel'

Concrete and lightweight concrete elements are today used in various building applications to a great extent all over the world. Replacing traditional thermal insulation like e.g. expanded polystyrene (EPS), extruded polystyrene (XPS) and polyurethane (PUR) by vacuum insulation panels (VIPs) is discussed in order to increase the thermal resistance without increasing the wall thickness. Compared to traditional concrete and lightweight concrete elements, slimmer elements may still achieve U-values low enough to fulfil passive house or zero energy requirements. Thus, sandwich elements with VIPs may be an alternative to the traditional solutions. However, there may be some problems related to the use of VIPs in such concrete elements. The alkaline environment in concrete may lead to reactions with the aluminium (Al) in the multi-layered laminate used as the VIP envelope, and destroy its barrier function. To investigate the influence of the alkaline environment on the durability of VIPs in general, and the VIP envelope in particular, various VIP and VIP envelope specimen experiments have been carried out. The VIPs were subjected to different alkaline solutions at different temperatures, with and without direct contact with the liquid alkaline solutions. A worst-case scenario was investigated when any additional protection of the VIPs was disregarded. The results from the VIP experiments showed various degrees of degradation effects. Depending on the temperature and the pH-value of the alkaline environment the VIPs were exposed to, physical and thermal changes were observed on some of the test specimens, while others were more or less unaffected by the exposure. In general, the temperature proved to be the hardest strain, when the VIPs in heating cabinet showed much greater signs of degradation than the VIPs at room temperature, more or less independent on the pH-value of the alkaline solution they were exposed to. Interesting results were also obtained from the VIP envelope specimen experiment, where the VIP envelope showed signs of degradation after only a short time in alkaline solution.

Buildings consume around half of the UK's total energy consumption and are responsible for almost 50% of UK's total carbon dioxide (CO2) emissions. Use of high thermal resistance insulation in buildings is critical to save the substantial amounts of space heating energy lost through building fabric. Conventional building insulation materials have higher thermal conductivity values ranging from 40 mWm-1K-1 (Glass fibre) - 26 mWm-1K-1 (Polyurethane foam) and require larger thicknesses to achieve stringent building regulation requirements which may not be feasible due to techno-economic constraints. Vacuum Insulation Panel (VIP) is a relatively new insulation for building applications that offers 5-8 times higher thermal resistance and can achieve significant space savings in buildings. VIPs are produced as a rigid panel comprising inner core board laminated in an outer high barrier envelope under evacuated conditions (< 5mbar). However, the main challenge for large scale acceptance of VIPs in building applications is their higher cost. VIPs have been shown to have an approximately 10 times longer payback compared to conventional EPS insulation due to their high initial cost. Expensive materials currently being used for VIP manufacturing such as fumed silica contribute to high cost of VIPs and it is critical to identify alternative low cost materials for VIP components to overcome the challenge of high cost. The aim of this thesis was to develop an alternative low cost material and investigate its suitability for use as VIP core. Expanded perlite, a low cost material was identified as a replacement of expensive fumed silica in a VIP core. Composite samples containing expanded perlite, fumed silica, silicon carbide (SiC) and polyester fibres were developed by dry mixing of the constituents in different mass ratios and their different properties were experimentally measured to identify optimum composition of composite. Gaseous thermal conductivity at different pressures was calculated from the pore size data obtained using Mercury Intrusion Porosimetry (MIP), gas adsorption and electron microscopy. Radiative conductivity of composite samples was measured using Fourier Transform Infrared (FTIR) to ascertain the opacifying effect of expanded perlite and opacifier (SiC). Centre of panel thermal conductivity of core boards of size 100mm x 100mm made of composite material at atmospheric pressure was measured by using a small guarded hot plate device. Average pore diameter values of expanded perlite decreased with the partial filling of fumed silica aggregates and was found to be in the range of 150-300 nm yielding lower gaseous conductivity values of 1.2-2.1 mWm-1K-1 at 100mbar and became negligible upon further decreasing pressures below 10 mbar. Core boards made of optimised composite containing 30% expanded perlite and 50% fumed silica along with SiC and polyester fibres was found to achieve centre of panel thermal conductivity of 28 mWm-1K-1 at atmospheric pressure and the average radiative conductivity of 0.67 mWm-1K-1 at 300K with its gaseous thermal conductivity at 1 mbar being 0.016 mWm-1K-1. According to the results of the thesis VIP prototypes consisting of core made with optimised composite consisting (50 mass% of fumed silica, 30 mass% of expanded perlite along with 8 mass% of fibre and 12 mass% of SiC) yielded centre of panel thermal conductivity of 7.4-7.6 mWm-1K-1 at pressure of 0.53-0.64 mbar. Opacifying properties of expanded perlite were observed and quantified. Expanded perlite reduced the radiative conductivity of the composite requiring smaller quantities of high density opacifiers such as SiC. For sample containing no expanded perlite, average radiative conductivity was calculated to be 1.37 mWm-1K-1 and radiative conductivity values decreased to 1.12 mWm-1K-1, 0.67 mWm-1K-1, 0.63 mWm-1K-1 and 0.50 mWm-1K-1 with mass ratio of expanded perlite 20%, 30%, 40% and 60% respectively. It was concluded that the solid conductivity of prototypes VIPs was 1.8-2 times higher compared to those of commercially available VIPs and is the main reason for higher centre of panel thermal conductivity.

Insulation is a key aspect of the energy consumption of a building. Determining the best type of insulation to implement in a building can be difficult, especially with new technologies emerging. This paper summarizes a study of one emerging type of insulation, Vacuum Insulation Panels, and explores the applicability of Vacuum Insulation Panels as building insulation. Building energy simulations were performed using EnergyPlus (Department of Energy simulation and energy analysis program). Simulations were done to compare the absence of insulation to the use of traditional building insulation and to the use of Vacuum Insulation Panels in relevant areas of a building. The simulations showed that in moderate to cold climates Vacuum Insulation Panels can account for an overall building energy savings of up to 10%. In warmer months, especially in warmer climates, the savings are insignificant. In hot climates the study showed no savings. For winter months in colder climates savings are at least 10% and reach as high as 16%. VIPs certainly have the potential to save energy in moderate to cold climates, especially during the coldest months of the year.

We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment.  Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60% if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hygrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The procedure incorporates specific steps exposing the wall to different climate conditions, ranging from cold and dry to hot and humid, with and without a pressure gradient. This study showed that air infiltration alone might decrease the thermal resistance of a residential wall by 15%, more for industrial walls. Results from the research underpin a discussion concerning the importance of a holistic approach to building design if we are to meet the challenge of energy savings and sustainability. Thermal insulation efficiency is a main concept used throughout, and since it measures utilization it is a partial measure of sustainability. It is therefore proposed as a necessary design parameter in addition to a performance indicator when designing building envelopes. The thermal insulation efficiency ranges from below 50% for a wood stud wall poorly designed with incorporated VIP, while an optimized design with VIP placed in an uninterrupted external layer shows an efficiency of 99%, almost perfect. Thermal insulation efficiency reflects the measured wall performance full scale test, thus indicating efficiency under varied environmental loads: heat, moisture and pressure. The building design must be as a system, integrating all the subsystems together to function in concert. New design methodologies must be created along with new, more reliable and comprehensive measuring, testing and integrating procedures. New super insulators are capable of reducing energy usage below zero energy in buildings. It would be a shame to waste them by not taking care of the rest of the system. This thesis details the steps that went into this study and shows how this can be done.
QC 20120228

Vacuum insulation panels (VIPs) represent a high performance thermal insulation material solution offering an alternative to thick wall sections and large amounts of traditional insulation in modern buildings. Thermalperformance over time is one of the most important properties of VIPs to be addressed, and thus the ageing effectson the thermal properties have been explored in this work. Laboratory studies of ageing effects are conducted over a relatively limited time frame. To be able to effectivelyevaluate ageing effects on thermal conductivity, accelerated ageing experiments are necessary. As of today, nocomplete standardized methods for accelerated ageing of VIPs exist. By studying the theoretical relationshipsbetween VIP properties and external environmental exposures, various possible factors for accelerated ageing areproposed. The factors that are found theoretically to contribute most to ageing of VIPs are elevated temperature,moisture and pressure. By varying these factors it is assumed that a substantial accelerated ageing of VIPs can beachieved.Four different accelerated ageing experiments have been performed to study whether the theoretical relationshipmay be replicated in practice. To evaluate the thermal performance of VIPs, thermal conductivity measurementshave been applied.The different experiments gave a varying degree of ageing effects. Generally the changes in thermal performancewere small. Results indicated that the acceleration effect was within what could be expected from theoreticalrelationships, but any definite conclusion is difficult to draw due to the small changes. Some physical changes wereobserved on the VIPs, i.e. swelling and curving. This might be an effect of the severe conditions experienced by theVIPs during testing, and too much emphasis on these should be avoided.
Vakuumisolasjonspaneler (VIP) er en høyisolerende materialløsning som kan være et alternativ til tradisjonell bygningsisolasjon. På grunn av god isolasjonsevne kan man ved bruk av VIP redusere veggtykkelsen og fortsatt tilfredsstille energikravene som stilles til moderne bygninger. En av de viktigste egenskapene for VIP er evnen til å bevare høy termisk ytelse over tid. I den sammenheng har aldringseffekter for VIP blitt undersøkt. Siden laboratoriestudier av aldringseffekter gjøres i løpet av et relativt kort tidsrom, er akselerert aldring nødvendig for å få evaluert termiske egenskaper over tid. Det finnes pr. i dag ingen standardisert metode for akselerert aldring av VIP. Det finnes likevel flere studier av sammenheng mellom klimaforhold og VIP egenskaper. Spesielt er gass og fuktdiffusjon inn i panelet behandlet grundig i litteraturen. Basert på dette er det foreslått flere mulige faktorer for aldring av VIP. De faktorene som er funnet å bidra mest til aldring av VIP er temperatur, fuktinnhold i lufta og utvendig lufttrykk. Ved å variere disse faktorene er fire forskjellige aldringsforsøk beskrevet og gjennomført.Konduktivitetsmålinger er blitt brukt som et mål på de termiske egenskapene til de testede VIPene. De forskjellige forsøkene viste forskjellig grad av aldringseffekt. Generelt var endringen i konduktivitetsverdier liten. Resultatene indikerer at akselerasjonseffekten var innenfor hva som kan forutsies fra de teoretiske sammenhengene. Likevel er det vanskelig å trekke noen definitive konklusjoner, både siden endringen var så liten, og fordi få paneler ble brukt i forsøkene. Noen fysiske endringer ble observert under forsøkene. Blant annet este et av panelene noe ut, mens et annet bøyde seg permanent. Man burde likevel ikke legge for mye vekt på disse effektene, siden de kan skyldes de relativt ekstreme testforholdene.

The diploma thesis deals with study of behavior of fibrous organic insulants under greatly reduced pressure (even to vacuum). Development, production and durability of vacuum insulating panels are described in the theoretical part as well as principles of heat transfer. Method for production of core of VIP, created using waste fibers from textile industry and agriculture, is described in the practical part. Verification of behavior during normal and reduced pressure (even to vacuum) was carried out on experimentally made core insulants.

Today’s buildings are responsible for 40% of the world’s energy use and also a substantial share of the Global Warming Potential (GWP). In Sweden, about 21% of the energy use can be related to the heat losses through the climatic envelope. The “Million Program” (Swedish: Miljonprogrammet) is a common name for about one million housing units, erected between 1965 and 1974 and many of these buildings suffer from poor energy performance. An important aim of this study was to access the possibilities of using Vacuum Insulation Panels (VIPs) in buildings with emphasis on the use of VIPs for improving the thermal efficiency of the “Million Program” buildings. The VIPs have a thermal resistance of about 8-10 times better than conventional insulations and offer unique opportunities to reduce the thickness of the thermal insulation. This thesis is divided into three main subjects. The first subject aims to investigate new alternative VIP cores that may reduce the market price of VIPs. Three newly developed nanoporous silica were tested using different steady-state and transient methods. A new self-designed device, connected to a Transient Plane Source (TPS) instrument was used to determine the thermal conductivity of granular powders at different gaseous pressure combined with different mechanical loads. The conclusion was that the TPS technique is less suitable for conducting thermal conductivity measurements on low-density nanoporous silica powders. However, deviations in the results are minimal for densities above a limit at which the pure conduction becomes dominant compared to heat transfer by radiation. The second subject of this work was to propose a new and robust VIP mounting system, with minimized thermal bridges, for improving the thermal efficiency of the “Million Program” buildings. On the basis of the parametric analysis and dynamic simulations, a new VIP mounting system was proposed and evaluated through full scale measurements in a climatic chamber. The in situ measurements showed that the suggested new VIP technical solution, consisting of 20mm thick VIPs, can improve the thermal transmittance of the wall, up to a level of 56%. An improved thermal transmittance of the wall at centre-of-panel coordinate of 0.118 to 0.132 W m-2K-1 and a measured centre-of-panel thermal conductivity (λcentre-of-panel) of 7 mW m-1K-1 were reached. Furthermore, this thesis includes a new approach to measure the thermal bridge impacts due to the VIP joints and laminates, through conducting infrared thermography investigations. An effective thermal conductivity of 10.9 mW m-1K-1 was measured. The higher measured centre-of-panel and effective thermal conductivities than the published centre-of-panel thermal conductivity of 4.2 mW m-1K-1 from the VIP manufacturer, suggest that the real thermal performance of VIPs, when are mounted in construction, is comparatively worse than of the measured performance in the laboratory. An effective thermal conductivity of 10.9 mW m-1K-1 will, however, provide an excellent thermal performance to the construction. The third subject of this thesis aims to assess the environmental impacts of production and operation of VIP-insulated buildings, since there is a lack of life cycle analysis of whole buildings with vacuum panels. It was concluded that VIPs have a greater environmental impact than conventional insulation, in all categories except Ozone Depilation Potential. The VIPs have a measurable influence on the total Global Warming Potential and Primary Energy use of the buildings when both production and operation are taken into account. However, the environmental effect of using VIPs is positive when compared to the GWP of a standard building (a reduction of 6%) while the PE is increased by 20%. It was concluded that further promotion of VIPs will benefit from reduced energy use or alternative energy sources in the production of VIP cores while the use of alternative cores and recycling of VIP cores may also help reduce the environmental impact. Also, a sensitivity analysis of this study showed that the choice of VIPs has a significant effect on the environmental impacts, allowing for a reduction of the total PE of a building by 12% and the GWP can be reduced as much as 11% when considering both production and operation of 50 yes. Finally, it’s possible to conclude that the VIPs are very competitive alternative for insulating buildings from the Swedish “Million Program”. Nevertheless, further investigations require for minimizing the measurable environmental impacts that acquired in this LCA study for the VIP-insulated buildings.
Dagens byggnader ansvarar för omkring 40% av världens energianvändning och  står också för en väsentlig del av utsläppen av växthusgaser. I Sverige kan ca 21 % av energianvändningen relateras till förluster genom klimatskalet. Miljonprogrammet är ett namn för omkring en miljon bostäder som byggdes mellan 1965 och 1974, och många av dessa byggnader har en dålig energiprestanda efter dagens mått. Huvudsyftet med denna studie har varit att utforska möjligheterna att använda vakuumisoleringspaneler (VIP:ar) i byggnader med viss fokus på tillämpning i Miljonprogrammets byggnader. Med en värmeledningsförmåga som är ca 8 - 10 gånger bättre än för traditionell isolering erbjuder VIP:arna unika möjligheter till förbättrad termisk prestanda med minimal isolerings tjocklek. Denna avhandling hade tre huvudsyften. Det första var att undersöka nya alternativ för kärnmaterial som bland annat kan reducera kostnaden vid produktion av VIP:ar. Tre nyutvecklade nanoporösa kiselpulver har testats med olika stationära och transienta metoder. En inom projektet utvecklad testbädd som kan anslutas till TPS instrument (Transient Plane Source sensor), har använts för att mäta värmeledningsförmågan hos kärnmaterial för VIP:ar, vid varierande gastryck och olika mekaniska laster. Slutsatsen blev att transienta metoder är mindre lämpliga för utföra mätningar av värmeledningsförmåga för nanoporösa kiselpulver låg densitet. Avvikelsen i resultaten är dock minimal för densiteter ovan en gräns då värmeledningen genom fasta material blir dominerande jämfört med värmeöverföring genom strålning. Det andra syftet har varit att föreslå ett nytt monteringssystem för VIP:ar som kan användas för att förbättra energieffektiviteten i byggnader som är typiska för Miljonprogrammet. Genom parametrisk analys och dynamiska simuleringar har vi kommit fram till ett förslag på ett nytt monteringssystem för VIP:ar som har utvärderats genom fullskaleförsök i klimatkammare. Resultaten från fullskaleförsöken visar att den nya tekniska lösningen förbättrar väggens U-värde med upp till 56 %. En förbättrad värmegenomgångskoefficienten för väggen i mitten av en VIP blev mellan 0.118 till 0,132 W m-2K-1 och värmeledningstalet centre-av-panel 7 mW m-1K-1 uppnåddes. Detta arbete innehåller dessutom en ny metod för att mäta köldbryggor i anslutningar med hjälp av infraröd termografi. En effektiv värmeledningsförmåga för 10.9 mW m-1K-1 uppnåddes. Resultaten tyder även på att den verkliga termiska prestandan av VIP:ar i konstruktioner är något sämre än mätvärden för paneler i laboratorium. En effektiv värmeledningsförmåga av 10.9 mW m-1K-1 ger dock väggkonstruktionen en utmärkt termisk prestanda. Det tredje syftet har varit att bedöma miljöpåverkan av en VIP-isolerad byggnad, från produktion till drift, eftersom en livscykelanalys av hela byggnader som är isolerade med vakuumisoleringspaneler inte har gjorts tidigare. Slutsatsen var att VIP:ar har en större miljöpåverkan än traditionell isolering, i alla kategorier förutom ozonnedbrytande potential. VIP:ar har en mätbar påverkan på de totala utsläppen av växthusgaser och primärenergianvändningen i byggnader när både produktion och drift beaktas. Miljöpåverkan av de använda VIP:arna är dock positiv jämfört med GWP av en standardbyggnad (en minskning med 6 %) medan primärenergianvändningen ökade med 20 %. Slutsatsen var att ytterligare användning av VIP:ar gynnas av reducerad energiförbrukning och alternativa energikällor i produktionen av nanoporösa kiselpulver medan användningen av alternativa kärnmaterial och återvinning av VIP kärnor kan hjälpa till att minska miljöpåverkan. En känslighetsanalys visade att valet av VIP:ar har en betydande inverkan på miljöpåverkan, vilket ger möjlighet att reducera den totala användningen av primärenergi i en byggnad med 12 % och utsläppen av växthusgaser kan vara minska, så mycket som 11 % när det gäller både produktion och drift under 50 år. Avslutningsvis är det möjligt att dra slutsatsen att VIP:ar är ett mycket konkurrenskraftigt alternativ för att isolera byggnader som är typiska för Miljonprogrammet. Dock krävs ytterligare undersökningar för att minimera de mätbara miljöeffekter som förvärvats i denna LCA-studie för VIP-isolerade byggnader.

QC 20151109

Simulations of heat and moisture conditions in a retrofit wall construction with Vacuum Insulation Panels
Textural and thermal conductivity properties of a low density mesoporous silica material
A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads
Evaluation of the thermal conductivity of a new nanoporous silica material for VIPs – trends of thermal conductivity versus density
A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels
ETICS with VIPs for improving buildings from the Swedish million unit program “Miljonprogrammet”

According to the Swedish Government's set targets for energy use and environmental quality imposed by the European Union, the total energy per heated unit area in residential and commercial buildings will have to be decreased by 20% in 2020 and 50% by 2050 in relation to the annual consumption of 1995. The building sector should additionally be completely independent of fossil fuels for energy usage, with the increasing sector of renewable energy continuously growing until 2020. In its current state, the number of multistory buildings and single-family houses in Sweden exceeds 4 000 000 units. In order to attain the set goals, renovation of the existing housing stock is a necessity given its current relatively slow turnover. As a result of the Swedish Million Unit Program undertaken during 1965−1974, about 750 000 apartments are currently in need of renovation in order to meet today's building standards. Simultaneously, new buildings are built with energy efficiency in mind. In this study an early stage methodology is developed for building refurbishment that takes advantage of a multi-faceted approach. The methodology comprises of multiple dimensions related to a techno-economic, environmental and building occupancy approach. The work presented herein includes a thorough literature review of decision making tools within the built environment and identifies major research efforts in sustainable refurbishment. The technical aspect of this study deals with the proper identification of high-efficient insulation materials that would serve one of the set purposes of energy efficiency when utilized within building envelopes. Further, results are shown for case studies, in which economic investments in Vacuum Insulation Panels (VIPs) and a coupled heat and moisture transport for predefined configurations of VIPs with supplementary insulation of balcony slabs and wall cross-sections are considered. The developed methodology also examines simulations of the total energy consumption utilizing a set of different insulation materials such as mineral wool and VIPs, for a number of locations in Northern and Southern Europe. The research findings of this study identify several aspects of a new developed tool for decision making, to be used in sustainable renovation and refurbishment.

QC 20120918

On peut distinguer deux familles d'isolants thermiques pour le bâtiment : les isolants dits traditionnels et les super-isolants qui se caractérisent par un pouvoir isolant plus performant qu'une simple lame d'air immobile (25 mW/m/K). Les Panneaux Isolants sous Vide (PIV) font partie de cette seconde catégorie. Un PIV n'est pas un matériau homogène, mais un système constitué d'un matériau de cœur mis sous vide et enfermé dans une enveloppe. La performance thermique du PIV repose sur la structure nano-poreuse du matériau de cœur et du vide primaire maintenu par l'enveloppe qui possède une très faible perméabilité aux gaz. Alors que les isolants traditionnels ont des conductivités thermiques allant de 21 mW/m/K pour la mousse polyuréthane à 50 mW/m/K pour les laines les moins performantes, celle des PIV est d'environ 4 mW/m/K à l'état neuf. Cependant, comme tout isolant, leur performance se dégrade dans le temps. Cette diminution de conductivité thermique est davantage préjudiciable pour les PIV à cause de leur très bonne performance initiale et de leur coût encore élevé. Il convient donc d'étudier l'évolution de leur performance thermique sur l'ensemble de leur durée de vie dans le bâtiment, c'est à dire 50 ans. Pour cela la modélisation a été choisie comme outil car l'expérimentation ne peut satisfaire ces durées d'étude. L'étude du comportement thermique des PIV passe par différents axes de recherches intervenant à différentes échelles.Le premier concerne les mécanismes de transferts des gaz à travers les enveloppes des PIV, aussi appelés complexes barrières. L'enjeu est d'améliorer notre compréhension sur les relations qui existent entre les propriétés morphologiques des complexes barrières et les phénomènes de diffusion de la vapeur d'eau et de l'air sec à travers les différentes couches de matériaux qui constituent ces complexes barrières. Les résultats obtenus ne permettent pas encore de proposer un modèle de diffusion juste à cette échelle, mais mettent en avant certaines tendances et mécanismes physiques qui ouvrent de nouvelles pistes d'exploration.Le deuxième axe de recherche s'intéresse au comportement hygro-thermique à l'échelle des panneaux. Un modèle numérique de PIV a été développé afin de prendre en compte ses propriétés géométriques, thermiques et hydriques dans le calcul la performance thermique globale du panneau. Le modèle intègre le vieillissement du matériau de cœur par la modification de son isotherme de sorption à la vapeur d'eau. Des PIV fabriqués avec différents types de matériaux de cœur sont étudiés dans différentes conditions constantes en température et humidité. Les résultats des simulations permettent de mieux comprendre l'évolution de la conductivité thermique des PIV, d'analyser leur comportement global et de déterminer les principales caractéristiques qui sont déterminantes pour améliorer leur performance.Enfin, la troisième partie des travaux de recherche est consacrée au développement d'une méthode d'analyse de la performance des PIV en conditions réelles d'installation dans un bâtiment, dans différent climats français et plusieurs applications d'isolation. L'objectif est tout d'abord de déterminer les sollicitations réelles auxquelles sont soumis les PIV mis en œuvre, et ensuite de simuler leur comportement thermique à long terme afin de prédire leur performance moyenne. Les résultats donnent des températures et humidités qui sont très variables selon les climats, les systèmes d'isolation et les saisons de l'année, mais celles-ci restent finalement relativement modérées. La performance thermique moyenne des PIV sur 50 ans dépend très peu des applications, mais plus des climats et encore plus du type de silice qui constitue leur matériau de cœur. Contrairement à ce que laissent supposer les essais à court terme, les silices hydrophobes sont les plus favorables. Selon les applications et les climats, la conductivité thermique moyenne des PIV peut varier entre 4,7 et 7,3 mW/m/K
Two types of thermal insulation materials exist for building application: the conventional insulation and the super-insulation materials which is characterized by an insulating performance higher than that of a simple layer of still air 25 mW/m/K). Vacuum Insulation Panels (VIP) belong to the second category. VIP is not a homogeneous material, but a product consisting of a core material maintained under vacuum by an envelope. The thermal performance of VIP is based on the nanoporous property of the core material and on the vacuum maintained by the envelope which has a very high gas barrier properties. While conventional insulation material has a thermal conductivity values from 21 mW/m/K for polyurethane foams to 50 mW/m/K for the worst wools, that of new VIPs is around 4 mW/m/K. Nevertheless, like every insulation materials, their performance degrades over time. This increase of thermal conductivity is even more detrimental for VIPs because of their very high initial performance and of their high cost. It is therefore important to study their thermal performance evolution over all their service-life in building, over 50 years. In order to manage this, modelling has been chosen, because experiments cannot be realised over such long periods. Studying the thermal performance of VIPs is going through different research topics which take place at different scales.The first one concerns the gas transfer mechanisms through the VIPs’ envelope, also called barrier complexes. The challenge is to improve our understanding of the relationship between the barrier complexes morphological properties and the water vapour and dry air diffusion phenomena through the different layers of materials which compose these barrier complexes. The results do not allow to provide a correct model at this scale, but put forward some trends and physical mechanisms that open up new avenues of exploration.The second research topic is focused on the hygro-thermal behaviour at panels’ scale. A numerical model of VIP has been developed in order to take into account its geometric, thermal and hygric properties in the global thermal performance calculation of the panel. The model integrates the ageing process of the core material by moving its water vapour sorption isotherm. VIPs made with different types of core material has been studied in different constant conditions of temperature and humidity. Simulation results allow to better understand the thermal conductivity evolution of VIPs, to analyse their global behaviour and to determine the main characteristics which are relevant to improve their performance.Then, the third part of the research studies is dedicated to the development of a method which allows to analyse the VIPs’ performance in real conditions of installation in building, in different French climate conditions and several insulation applications. The aim is first to determine the real solicitations imposed on VIP, and then to simulate their long-term thermal performance in order to predict their mean performance. Results show a large dispersion of solicitations submitted to VIPs according to the climate conditions and insulation systems. Temperatures and humidities are highly variable according to the seasons, but finally remain relatively moderate. It is turns out that the mean thermal performance of VIPs over 50 years differs little from applications, but more from climate conditions and even more from the type of silica used for the core material. Contrary to what the short term tests would suggest, hydrophobic silicas are most favourable. The mean thermal conductivity of VIPs can varies between 4.7 and 7.3 mW/m/K

Nanoporous materials for gas purification and thermal insulation have been studied and developed for application in many areas. It is known that a single adsorbent may not adequately control multiple contaminants. Further the utilization of nanoporous material as thermal insulator in building applications is limited due to high cost. Moreover, in view of the global environmental movement for clean air and reduction of heating energy consumption in built environment, the development of new and better nanoporous materials will not only facilitate major advances in gas adsorption and thermal insulation technology, but also meet the new challenges that cannot be met with the nanoporous materials that are currently available. This thesis presents a synthesis of new nanoporous silica based materials, and the characterization and application of these materials for molecular filtration and thermal insulation. Commercial nanoporous materials have been used for benchmarking for the pore properties, the applicability, and the performance of these new materials. First a double metal-silica adsorbent has been synthesized. The preparation procedure is based on the use of sodium silicate coagulated with various ratios of magnesium and calcium salts which yields micro-meso porous structures in the resulting material. The results show that molar ratios of Mg/Ca influence the pore parameters as well as the structure and morphology. The bimodal pore size can be tailored by controlling the Mg/Ca ratio. In the second synthesis, pure mesoporous silica, SNP has been prepared using glycerol as pore forming agent and monovalent salts as coagulant. This leads to material with large surface area and uniformed pore size centred at 43 or 47 nm.  The materials further exhibits a low bulk density in the range of 0.077 to 0.122 g/ml and possess a high porosity in the range of 95-97%. The influence of acid type (organic or inorganic) on the pore parameters and on the tapped density has also been investigated.   A synthesis method has also been developed for the preparation of carbon-silica composites. The method involves a number of routes, which can be summarised as addition of activated carbon particles to (I) the paste, (II) the salt solution, or (III) with the sodium silicate solution. In route II and III the activated carbon is present before coagulation. The routes presented here leads to carbon-silica composites possessing high micro porosity, meso porosity as well as large surface areas. The results further shows that pore size distribution may be tailored based on the route of addition of the carbon particles. Following route I and III a wide pore size (1-30 nm) was obtained whereas by route II a narrow pore size (1-4 nm) was observed.     MgCa-silica chemisorbents were also developed using either potassium hydroxide or potassium permanganate as impregnate chemicals. A direct or post-impregnation procedure was employed. The results revealed that the impregnate route and amount cause a reduction in both specific surface area and pore volume. Finally the thermal conductivity and dynamic adsorption of H2S, SO2 andtoluene were measured. Results show that at room temperature and atmospheric pressure, a thermal conductivity of 28.4 and 29.6 mW/m.K were obtained for the SNP mesoporous silicas. The dynamic adsorption behaviour of the chemisorbents and composites indicate their ability to absorbed H2S, SO2 andtoluene respectively. The highest H2S uptake corresponds to chemisorbents with 11.2-13.6 wt% KMnO4. The effect of impregnation route, amount of KMnO4 and its location in the pore system are likely the key factors in achieving a large H2S uptake. For SO2 adsorption, the highest uptake capacity was observed for MgCa-68/32-KOH. The results further suggest that the key to large SO2 uptake is as a result of the synergetic effect between large mesopore diameter and extensive mesopore volumes. Carbon-silica composites with carbon content 45 wt % exhibits high toluene adsorption with composite via route I having the highest toluene adsorption capacity (27.6 wt % relative to carbon content). The large uptake capacity of this composite was attributed to the presence of high microporosity volume and a wide (1-30 nm) bimodal pore system consisting of extensive mesopore channels (2-30 nm) as well as large surface area. These capacity values of carbon-silica composites are competitive to results obtained for commercial coconut based carbon (31 wt %), and better than commercial alumina-carbon composite (9.5 wt %).

QC 20130408

Increasingly strict demands for the use of energy in buildings have put pressure on the construction industry to look for new ways to improve the built environment. This study has investigated three technologies, low-emissivity (low-e) materials, phase change materials (PCM) and vacuum insulation panels (VIP), and provided a state-of-the-art review of commercial products of these materials. Though the materials have different effects when applied to buildings, they all aim to increase energy efficiency and improve thermal comfort for the inhabitants.For the mentioned materials, examples of how they are implemented in buildings have been given and research that have been conducted and research that is still being conducted have been investigated. Reflections on steps that should be taken for future research have also been investigated. Herein lies the focus on improving the current technology, possible new technologies and steps that are needed for the materials to achieve large-scale application in the construction sector.

Objectives set by the EU means that all buildings after 2020 has to be nearly zero energy buildings. This means that thicker layers of insulation have to be added in the wall construction which makes the wall thicker. It means that the living area will be reduced. Vacuum insulation is a highly effective type of insulation and because of its low thermal conductivity it has the ability to reduce the thickness in wall structures. This project investigates a proposal to apply vacuum insulation in one-storey buildings. In order to achieve the goals of the project, a proposal for a one-storey building was developed. Calculations have been made and the proposal was developed as an alternative to show how to construct a family home containing vacuum insulation. The empirical data was collected through interviews, document analysis and literature studies. The collected data was analyzed together with the theoretical framework that has been developed through literature studies and document analysis. Creating a wall construction containing vacuum insulation as a primary insulation usually means that the wall will be considerably thinner than a wall construction with traditional insulation. This means that living area can be saved. Vacuum insulation has to be protected properly as it is easily punctured where upon it loses the most of its insulation capacity. Vacuum insulation is not common on the Swedish construction market today, this is due to many factors, including its high price. Vacuum insulation is a good problem solver which can be used in bay windows to gain extra space. One can also make use for it in tight spaces. From an economic point of view vacuum insulation offers the greatest advantages in cities where living space is considerably higher than in rural areas. To take part of the work there is no need for prior knowledge about vacuum insulation. The project focuses only on wall structures in the single-storey villas, therefor, no indentations has been made on the floor- and roof structures or other building types. The project only focuses on newly constructed buildings. No calculations are made for moisture or production costs.
Mål uppsatta av EU innebär att samtliga byggnader som uppförs vid år 2020 måste vara nära-nollenergihus. För väggarna i konstruktionen innebär det att tjockare lager av isolering måste adderas vilket ger bredare väggkonstruktioner. Bredare väggkonstruktioner innebär även att boarean minskas. Vakuumisolering är ett högeffektivt isoleringsmaterial som genom sin låga värmeledningsförmåga har möjligheten att minska tjockleken vid väggkonstruktioner på grund av dess tunna skikt. Arbetet utreder ett förslag att applicera vakuumisolering i enplansvillor. För att uppnå arbetets mål har ett förslag på enplansvilla tagits fram. Beräkningar har gjorts och förslaget är framtaget som ett alternativ för att visa hur en villa innehållande vakuumisolering kan utformas. Det empiriska materialet har samlats in genom intervjuer, dokumentanalyser samt litteraturstudier. Empirin analyseras sedan tillsammans med det framtagna teoretiska ramverket genom litteraturstudier och dokumentanalyser. Att skapa en väggkonstruktion med vakuumisolering som primär isolering betyder oftast att väggen blir avsevärt mycket tunnare än en väggkonstruktion av traditionell isolering, vilket betyder att boarea kan sparas. Vakuumisolering måste skyddas på rätt sätt i väggkonstruktioner eftersom materialet lätt punkteras varpå det förlorar den största delen av sin isoleringsförmåga. Idag är inte vakuumisolering utbrett på den svenska byggmarknaden vilket beror på många faktorer, bland annat dess höga pris. Vakuumisolering är en väldigt bra problemlösare som med fördel kan användas i burspråk för att vinna extra utrymme. Det kan även användas i trånga utrymmen som elnischar. Ur ekonomisk synpunkt ger vakuumisolering störst fördel i städer där boarea per kvadratmeter är högre än motsvarande på landsbygden. För att ta del av arbetet krävs inga förkunskaper om vakuumisolering. Arbetet fokuserar endast på väggkonstruktioner i enplansvillor, därför har inga fördjupningar skett på golv- och takkonstruktioner eller andra byggnadstyper. Enbart nybyggnationer av trästommar är utrett. Beräkningar är inte gjorda för fukt och produktionskostnader.

The motivation for development of energy efficiency and implementation of novel advanced materials applied in buildings can be traced to increasing energy costs in conjunction with an enhanced environmental awareness among people. This doctoral dissertation presents contributions towards sustainable building, where factors such as building technology, energy efficiency in buildings, workers' health issues during construction measures, and certain economic considerations for renovation of buildings have been considered. The research study aims to provide a knowledge base for motivating building owners to renovate buildings based on energy efficiency and improved indoor environment. The initial phase of the research study identifies a detailed description of common drivers, expected in renovation projects by building owners. In the second phase, an information base is identified which may facilitate the bidding processes for decision makers by means of technological, social and economic aspects. The aforementioned information base can also contribute to attentive decisions regarding sustainable renovation and energy saving measures. A strategy was developed within the Renovation Workshop of Riksbyggen, in order to promote energy saving measures concurrent with major renovations in residential buildings. This operational decision support process was applied in a tenant owners' cooperative in Sweden. The objective of this process was to showcase and more importantly to implement energy saving measures, based on knowledge transfer between different parties involved in the renovation project. For the conducted case study, this process was shown to be of great importance when decisions regarding energy saving measures in conjunction with scheduled renovations are being planned. A unique case study was conducted on two of the most commonly used environmental certification programs for buildings in Sweden; Environmental Building (Miljöbyggnad) and GreenBuilding. Following a granted access to a limited database of submitted applications to Sweden Green Building Council, the most common mistakes in these were identified and categorized. This study contributed to further understanding about the level of ability among building consultants, comprehension of environmental certification, and enhancement of the ability to produce high-quality calculations concerning building-related energy usage. In addition, this insight can provide a basis for planning of continuing education of consultants within the field of building technology. For a church building, a study was conducted subsequent to an exchange of an existing electric coil heating system to a hydronic ground source heat pump system. Analyses of the energy demand and energy signature, prior to and after installation were carried out. The replacement of the original heating system with a ground source heat pump system for the church building constitutes a reduced energy consumption level of approximately 66%, at the average outside temperature of -2.30 °C. This study demonstrated that data from a detailed electric bill can be utilized in order to obtain the energy signature of the building and henceforth assess the energy savings. One aspect of the research, examined the decision making process related to sustainable renovation and refurbishment in buildings. The utilized methodology identified three distinct phases in order to instigate an engagement in sustainable renovation, by means of questionnaires and semi-structured interviews. In particular, the attitudes of stakeholders in Sweden, Denmark and Cyprus to sustainable building were studied through three separate case studies. Within the framework of this study, it was identified that building physics and durability are among the most important drivers for energy renovation. The results provided an insight into the renovation process in the aforementioned countries and identified that drivers such as improvement of indoor air quality and elimination of moisture in the building envelope are also of crucial importance. Another aspect of the conducted research highlights workplace accidents occurring within the Swedish construction sector. The purpose of this study was to serve as a useful tool to track the working environments of construction workers in order to reduce health and safety issues within the construction sector. The findings of this research suggest that despite laws, regulations or additional factors that seek to ensure a safe and healthy environment for construction workers, the Swedish construction work force still faces challenges. Moreover, it is identified that construction workers participating in the study call for additional measures to ensure occupational health and safety. Improved knowledge of economic performance and technical results of renovations can contribute to a snowball effect, with more property owners recognizing the value of energy aspects and thus provide an increased level of energy savings.

QC 20140127

A Concept for promotion of sustainable retrofitting and renovation in Early Stages (ACES)

碩士
中國文化大學
造紙印刷研究所
85
The open cell rigid polyurethane (PU) foam for vacuum insulationpanel (VIP) which contain non-CFCs or non-HCFCs and with high thermal resistancehave been studied in this research. The objective was to identify factorswhich influence the batch manufacture efficiency and the thermal conductivityperformance of the PU vacuum insulation panels.The thermal conductivity performancesof vacuum insulation panels were experimentally investigated. the changeof thermal conductivity of PU VIPs are as functions of drying pretreatmenttemperature and time, PU foam cell size, the encapsulation barrier, getter, evacuation pressure.The VIPs have a low thermal conductivity (7.1 mW/mK), underthe 120oC, 10 minutes pretreatment, 14 mTorr evacuation pressure, the compositionof CPP/Al/PET laminated film bag and with zeolite and active carbon mixturegetters, which insulation effectiveness is four times better than those formerCFCs blowing rigid PU foam.

Glass fiber core Vacuum Insulation Panels (VIPs) have thermal performance per unit thickness of about 5-10 times higher than the traditionally used building insulation materials such as mineral wool, XPS, EPS, foam, etc. This advantage of VIP has made it very attractive new option for innovative building designs. Especially in Canada, where some of the areas have long and very cold winters. Confidence in the service life of a building material is necessary before putting a product to market. Extensive research has been conducted on the product development, quality improvement, and field application of VIPs around the world. However, there is lack of consistent and simple prediction method for the long-term thermal performance of VIPs. This paper discussed the process and performance of a field project using glass fiber VIPs to retrofit a commercial building in Yukon, Canada. The thermal performance of the VIPs used in this project was continuously monitored and critically analyzed since the start in 2011. The results have shown satisfactory thermal performance of VIPs for the past 8 years. The findings were also used to validate glass fiber core VIP accelerated aging tests conducted by the National Research Council Canada (Ottawa), and the aging rate of VIPs in a cold and dry climate was determined. The second part of this study investigated the monitored performance results from two sets of simplified accelerated laboratory aging tests, the results were analyzed with the aim to separate the impact of air diffusion from water vapour on the long-term thermal performance of glass fiber VIPs. In addition, this study also investigated the potential application of VIPs in balcony constructions to reduce heat transfer through thermal bridges. Computer modeling exercises, using a benchmarked (EN ISO 10211) three-dimensional transient and steady-state heat transfer simulation tool HEAT3, were carried out on the most optimal (thermal performance) balcony assemblies of wood framed buildings using VIP as insulation. This niche application of VIPs can significantly increase the energy efficiency of building envelopes/skins in extreme climates of Canada and elsewhere in the world.
Graduate
2021-11-06

Thermal resistance per unit thickness for Vacuum Insulation Panel (VIP) is 5 to 10 times higher than conventional insulation materials. This makes VIP an attractive option for retrofitting exterior building envelopes. Insulation can be added in an exterior wall either on the interior side, exterior side or in the available stud cavity. VIP has high vapor diffusion resistance factor and could lead to moisture management risk in the wall layers because of the steep temperature gradient in the wall generated due to very high thermal resistance of VIP. VIP is a relatively new insulation material for building envelope construction, thus the hygrothermal or moisture management performance of VIP-insulated exterior building envelopes need to be critically analyzed before its application. This study aims to evaluate the moisture management risk associated with wood-frame stucco-cladded exterior walls retrofitted with VIP using a 2-D hygrothermal simulation tool WUFI-2D. Eight North American locations were considered, based on Moisture Index (MI) which varied between 0.13 and 1.17, and two different indoor hygrothermal loading conditions as prescribed by the ASHRAE 160P and EN 13788, respectively. The outputs from hygrothermal simulations (water content, relative humidity and temperature) were critically analysed and expressed further using freeze-thaw cycles and RHT indices. The results show that the appropriately designed VIP retrofitted walls can have superior moisture management performance as compared to conventional stucco-cladded wall.
Graduate