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University of Nottingham Department of Architecture and Built Environment

Research Project (K133RP) -Vacuum Insulation Panels in Building Application: A Review, Testing and Modelling

Yuda Sun(4158944)

08 May 2013

A dissertation submitted in partial fulfilment of the regulations for the Degree of Bachelor of Engineering in Engineering in Architectural Environment Engineering at the University of Nottingham, 2013.


ABSTRACT European Commission decided to reduce 20% energy use in European Union for house heating before 2020, and half of that in 2050 compared to the energy use in 1990. To reach the target, the amount of insulation in buildings has to be increased significantly. Because of the limited thermal resistance performance of conventional insulations, lots of novel thermal insulation materials have been introduced to the construction market during the last decade. One of the highest thermal performance materials is the vacuum insulation panel (VIP) whose thermal conductivity is 5 to 10 times less than conventional insulation materials. The main benefit of the panel is that it can offer a high thermal resistance in buildings with very slim construction structures. However, some main obstacles still exist, such as, thermal bridge effect because of envelope and thermal performance degradation through service year. In addition, VIP is expansive, very fragile and cannot be cut in site. All these effects should be taken in consideration for building application.

The purpose of the research project is to assess the thermal performance of VIPs and only to analyse its application in buildings. The research aspects are broadly concerned its working principles, thermal resistance properties, costs, and life-cycle performance, etc. During the research, a simple lab testing and software modelling of a particular house are done to exam VIPsâ€&#x; real and theoretic thermal performance when comparing to other building insulation materials. The lab testing shows that VIP has the best thermal resistance performance among aerogel, EPS, and glass wool. The modelling results indicate that although VIP can achieve a very good thermal performance in E.ON House with slim construction elements, initial cost is high. EPS insulated construction may be a desired consideration instead of VIPs.

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ACKNOWLEDGEMENTS First of all, I would like to thank my supervisor Professor Saffa Riffat, for his enthusiasm, his encouragement, and his resolute guidance to my direction of final report. I am also indebted to PhD student Sultan Alotaibi, he gave me a lot of supports all the time of research and experiment. I would like to thank Bob, David, Xu Yu, Haipeng Xu, and any other lab technicians for their help and hard work during my experiment. Although I may not know their full names, I will remember them forever.

I would like to thank my parents, for their love and support during my undergraduate study in the University of Nottingham. I would also like to thank my personal tutor-Dr. Rabah Boukhanouf, for his great suggestions and guides in the two years. Thanks to Dr Hao Liu and Dr Edward Cooper, for their hard work in the course and the research project module.

At last, I would like to express my sincere gratitude to all the individuals who have given me supports and encouragement during my study in Nottingham.

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CONTENTS Abstract .................................................................................................................................. i Acknowledgements ............................................................................................................... ii Contents ................................................................................................................................ iii List of figures......................................................................................................................... v List of tables ......................................................................................................................... vi CHAPTER 1

INTRODUCTION ....................................................................................... 1

CHAPTER 2

INTRODUCTION TO VIP .......................................................................... 3

2.1. Working principles of VIPs ........................................................................................ 3 2.2. Critical elements ......................................................................................................... 4 2.2.1. Core ......................................................................................................................... 4 2.2.2. Envelope .................................................................................................................. 6 2.2.3. Getters, desiccants and opacifiers ............................................................................ 6 2.3. VIP in building applications ....................................................................................... 7 CHAPTER 3

COMPARE VIPS WITH OTHER INSULATIONS .................................. 10

3.1. Introduction to other building insulations ................................................................ 10 3.1.2. Conventional insulations ....................................................................................... 10 3.1.3. Advanced insulations ............................................................................................. 10 3.1.4. Performance comparison of insulations ................................................................ 11 3.2. Advantages and disadvantages ................................................................................. 14 CHAPTER 4

EXPERIMENTAL DESIGN AND PROCEDURES ................................. 15

4.1.

Introduction to the experiment ........................................................................... 15

4.2.

Description of theory ......................................................................................... 16

4.3.

Description of apparatus .................................................................................... 17

4.3.1. Testing box............................................................................................................. 17 4.3.2. Thermocouples ...................................................................................................... 18 4.3.3. Heater..................................................................................................................... 19 4.3.4. Heating controller .................................................................................................. 19 iii


4.4. Experimental procedures .......................................................................................... 19 4.5. Results and discussion .............................................................................................. 20 4.5.1. Internal surface temperature .................................................................................. 20 4.5.2. External surface temperature ................................................................................. 21 4.5.3. VIP thermal performance....................................................................................... 21 4.5.4. Aerogel thermal performance ................................................................................ 22 4.5.5. EPS thermal performance ...................................................................................... 23 4.5.6. Glass wool thermal performance ........................................................................... 23 4.6. Conclusion ................................................................................................................ 24 4.7. Recommendation ...................................................................................................... 24 CHAPTER 5

SOFTWARE MODELLING OF E.ON HOUSE ....................................... 25

5.1. Introduction to the modelling ................................................................................... 25 5.2. Description of modelling process ............................................................................. 27 5.3. Results ...................................................................................................................... 31 5.3.1. Modelling results ................................................................................................... 31 5.3.2. Manual calculation ................................................................................................ 33 5.4. Compare and discussion ........................................................................................... 36 5.4.1. Software vs. manual calculation ............................................................................ 36 5.4.2. Space saving .......................................................................................................... 37 5.4.3. Economic analysis ................................................................................................. 37 5.5. Conclusion ................................................................................................................ 38 Chapter 6 CONCLUSIONS................................................................................................. 40 References ........................................................................................................................... 42 Appendices .......................................................................................................................... 46

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LIST OF FIGURES Figure 2.1: Picture and cross section of a small sized VIS-test specimen..................... 3 Figure 2.2: Section of a VIP .......................................................................................... 3 Figure 2.3: Gaseous thermal conductivity function at 300K....................................... 5 Figure 2.4: Thermal conductivity of different core materials ........................................ 5 Figure 2.5: Three types of envelope .............................................................................. 6 Figure 2.6: House insulated with 20mm VIP encapsulated in 20mm EPS which were attached by a rail system (Photo: Zwerger and Klein, 2005) ................................ 8 Figure 2.7: A building retrofitted on the exterior with 15mm VIP using a special plastic rail system (Photo: ZAE Bayern) .......................................................................... 8 Figure 2.8: The floor of a gym was retrofitted with 20mm VIP which decreased the U-value from 0.43 to 0.15 W/m2K ........................................................................ 9 Figure 2.9: A flat roof equipped with VIP covered by a water repellent layer .............. 9 Figure 3.1: Insulation thickness to achieve U-value of 0.25 W/m2K .......................... 14 Figure 4.1: The whole testing apparatus ...................................................................... 17 Figure 4.2: Core skeleton of the testing box ................................................................ 17 Figure 4.3: Pictures of the four insulation panels and the wooden frame ................... 18 Figure 4.4: Location of heater and thermometer ......................................................... 18 Figure 4.5: Internal surface temperature...................................................................... 20 Figure 4.6: External surface temperature .................................................................... 21 Figure 4.7: VIP surfaces temperature .......................................................................... 22 Figure 4.8: Aerogel surfaces temperature .................................................................... 22 Figure 4.9: Polystyrene surfaces temperature.............................................................. 23 Figure 4.10: Glass wool surfaces temperature............................................................. 24 Figure 5.1: Image of north face ................................................................................... 26 Figure 5.2: Image of south face ................................................................................... 26 Figure 5.3: Key conclusion of each case ..................................................................... 38

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LIST OF TABLES Table 1.1: Comparison of U-value requirements in 2006 and 2010 .............................. 1 Table 3.1: Properties of some insulation materials ...................................................... 12 Table 3.2: Insulation materials thermal conductivities chart ....................................... 13 Table 3.3: Advantages and disadvantages of VIPs and conventional insulations ....... 15 Table 4.1: Properties and produce companies of the four insulation panels ............... 18 Table 4.2: Thermal properties of the four insulation materials ................................... 24 Table 5.1: Basic information of E.ON House .............................................................. 26 Table 5.2: Some internal condition assumptions of E.ON House ............................... 31 Table 5.3: Manual calculation of fabric heat loss of original building ........................ 34 Table 5.4: Manual calculation of fabric heat loss of 20mm VIPs enhanced building . 34 Table 5.5: Glazing area in each orientation ................................................................. 35 Table 5.6: Solar heat gain of the house on 29th January ............................................. 35 Table 5.7: Thicknesses of external walls and perimeter .............................................. 37 Table 5.8: Thicknesses of external walls and perimeter .............................................. 37 Table 5.9: Initial costs and payback period of each case ............................................. 38

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CHAPTER 1

INTRODUCTION

Vacuum insulation panel, abbreviated as VIP, is one of the highest-performance thermal insulation products on the market today [1]. The popularity of its application has continuously increased since about two decades ago. The first VIP appears in the 1930s when a rubber enclosed porous body was filed on German patent. Around 20 years later, a patent on a core of glass wool contained in a steel foil was filed in the US. In the year of 1963, the first patent of a panel with nanostructured material core was filed. They were first introduced to refrigeration industry in the USA, Japan and European countries until the 1990s and were followed by applications in the buildings [2]. Therefore, the application of VIPs in the building industry was late. It first appeared in Europe at the beginning of the 21st century and now spreading all over the world [3].

The thermal insulation markets are influenced by building regulations and legislations that aim to reduce carbon emissions. From 2006 to 2010, thermal transmittance (also known as U-value) of each construction element changed a lot according to the Approved Document L of the Building Regulations [4]. The requirements of U-value for new construction buildings are listed in Table 1.1. 2006(W/m2K)

2010(W/m2K)

Roof

0.25

0.20

Wall

0.35

0.30

Floor

0.25

0.25

Window/external wall

2.20

2.00

Party wall

N/A

0.20

Table 1.1: Comparison of U-value requirements in 2006 and 2010

In terms of energy efficiency, it is more cost-effective to invest in high levels of insulation materials of a building than investing in expensive heating technologies. Furthermore, studies also show that installing renewable energy equipment is also far less cost-effective 1


than insulating existing buildings to a low carbon future. Thus, insulation is an essential consideration of sustainable building design and it is worth taking time to choose a right insulation material for a building or house [5]. A well-insulated house reduces energy for keeping it warm in winter and cool in summer. However, the traditional insulation material developed before the 1960s has a limited thermal conductivity which equals to the one of air. Now some advanced insulation technologies such as vacuum technology have reduced initial thermal conductivity up to 10 times than the so-called air thermal limit [6]. Ever since 1990s, VIPs have developed significantly though some technical constraints still exist. At the same time, new vacuum based materials are developing such as vacuum insulation materials and nano insulation materials.

The research project will focus on VIPsâ€&#x; applications in building industry. There are a lot of advantages as well as disadvantages of using VIPs in buildings. For example, if VIPs are used as insulation material in a building rather than conventional insulations, building construction elements thicknesses and energy consumption can be necessarily reduced, but the construction cost and maintenance fee will increase a lot. Therefore, it is best to find out an optimised method of using this kind of advanced insulation material to achieve a balance between energy, design, and economy. This research project aims to review basic knowledge of VIPs, conduct a testing and modelling in both laboratory and computer to figure out the effects of VIPs on the thermal performance, construction costs and design of a building. Working principles and critical components of VIPs will be introduced. VIPs will also be compared with other insulation materials: both conventional and advanced materials. In the laboratory experiment, VIPs, aerogel, EPS, and glass wool are tested together. In the modelling, Ecotect is used to analysis the thermal performances of E.ON House in the University of Nottingham under original, EPS enhanced, and VIP enhanced states.

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CHAPTER 2

INTRODUCTION TO VIP

Figure 2.1: Picture and cross section of a small Figure 2.2: Section of a VIP sized VIS-test specimen There are three categories of vacuum-based insulating solutions currently, all of which have great performance of thermal resistance. Apart from VIPs, there are vacuum insulating sandwiches (VISs), and Vacuum insulation glazing (VIG). VIS is a more robust version of panel, the core structure within which is covered by stainless steel envelope and a circular membrane (shown in Figure 2.1) [7]. VIG is a kind of double-glazing with a vacuum between two panes of glass and low-e coatings with an excellent insulating property [8] [9]. What we concentrate here in the project, VIPs, can be defined as “an evacuated foil-encapsulated open porous material as a high performance thermal insulating material� [1]. VIP is a composite material with a fine powder core wrapped in a heat sealed metalized multi-layered film, companies with getter/desiccant and opacifer inside the core, the structure of the panel is shown in Figure 2.2. VIP as one of the new promising insulation materials was discovered as early as in the 1930s, but only limited commercial products are available until now because of some limitations [10]. Therefore, a lot of researches can be done to overcome these obstacles.

2.1. Working principles of VIPs It is widely known that a thermos keeps hot contents hot and cold contents cold by separating inside and outside environment with a vacuum. The working principle of a VIP is similar 3


with a thermos [11]. Heat is conducted by three methods: convection, conduction, and radiation, in which two methods conduction and convection can be prevented by vacuum. To explain more specifically by using an equation, the total density of the heat flow rate in such porous materials can be divided into four types of heat transfer processes: heat transfer via radiation (q đ?‘&#x; ), heat transfer via conduction of the solid core skeleton (q đ?‘?đ?‘‘ ), heat transfer due to inside gas conduction (q đ?‘” ), and heat transfer due to the inside gas convection (q đ?‘?đ?‘Ł ). The total heat flow density is q đ?‘Ąđ?‘œđ?‘Ą , which can be estimated by a sum of these four heat transfer mechanisms [1]. q đ?‘Ąđ?‘œđ?‘Ą (đ?‘Š/đ?‘š2 ) = q đ?‘&#x; + q đ?‘?đ?‘‘ + q đ?‘” + q đ?‘?đ?‘Ł (+q đ?‘?đ?‘œđ?‘˘đ?‘?đ?‘™đ?‘–đ?‘›đ?‘” )

(2.1)

q đ?‘?đ?‘œđ?‘˘đ?‘?đ?‘™đ?‘–đ?‘›đ?‘” in the Eqn. (2.1) is a complex term due to the interaction between different transfer mechanisms for powder and fibre materials, which is mostly neglected. Similarly, the thermal transport through a material can be quantified by the materialsâ€&#x; thermal conductivity Îťđ?‘Ąđ?‘œđ?‘Ą , which is again a sum of single values. Îťđ?‘Ąđ?‘œđ?‘Ą = Îťđ?‘&#x; + Îťđ?‘?đ?‘‘ + Îťđ?‘” + Îťđ?‘?đ?‘Ł

(2.2)

The effective reduction of the gas thermal conduction Îťđ?‘” and the air and moisture convection within the pores Îťđ?‘?đ?‘Ł appears in a theoretical perfect vacuum, which achieve their limit value of „zeroâ€&#x;. Therefore, Eqn. (2.2) can be reduced to the first two terms: Îťđ?‘Ąđ?‘œđ?‘Ą = Îťđ?‘&#x; + Îťđ?‘?đ?‘‘

(2.3)

2.2. Critical elements 2.2.1. Core Because of the function of gaseous thermal conductivity, the pore diameter, and the gaseous pressure, the core material has to fulfil different requirements to be suitable for vacuum insulation (the relationship is shown in Figure 2.3) [3]:

ď Ź Material pore diameter has to be very small. According to Figure 2.3, it is hard to reduce gas conductivity in insulation materials with large pore sizes. ď Ź The material should have 100% open cell structure to be able to be evacuated any gas in it. 4


ď Ź The material should be resistant to compression. The pressure load on the panel is approximately equal to the standard atmospheric pressure, 1 bar. Thus, the core material has to be stable enough to prevent the pores from collapsing. ď Ź The material should be as impermeable as possible to infrared radiation. This is necessary to reduce the radiation transfer to ensure the very low conductivity of the panel.

Figure 2.3: Gaseous thermal conductivity

Figure 2.4: Thermal conductivity of

function at 300K

different core materials

Many organic and inorganic materials such as polystyrene foam and glass fibre with an open cell structure are available to use as a core for VIPs. In the Asian market, glass fibre and open cell foam is used as core materials which require a tighter envelope and getters [12]. The trend in Europe is to use nano-porous core materials which can make getters unnecessary and envelopes thinner [13]. Alternative cores consisting of polycarbonate multi-layered beam and radiation shields have been reported by Kwon et al [14]. Specific heat conductivity for inorganic and organic materials can be defined as a function of gas pressure, as shown in Figure 2.4 [1]. From it, it can be found out that a very high quality of vacuum needs to be guaranteed if a conventional insulation is chosen as a core material. An intake of air through the envelope will result in a fast increase of thermal conductivity. However, core powder boards made of fumed silica have very good achievement. It has a low conductivity close to 0.003W/mK up to 50mbar and 0.02W/mK at ambient pressure, approximately half the thermal conductivity of traditional insulation. Now, fumed silica has been the most common core material in Europe. 5


2.2.2. Envelope The outer envelope is another critical part of a VIP which is responsible to prevent air and moisture from entering the panel and to resistant high ambient pressure. The envelope of VIPs consists of different layers covering the whole core element with an overall thickness of 100-200Îźm [15]. It is common to use aluminium layers in these multi-layer films to well prevent gas and water permeation, although its thermal conductivity is relatively high. In order to moderate the high heat flux at the edges and corners caused by using aluminium layers, it is important to consider how to minimize these thermal edge losses during installation [16]. Currently, three different types of envelopes are being used (shown in Figure 2.5) [13]:

1. Metal foils consisting of a central aluminium barrier layer, laminated between an outer PET layer for scratch resistance and an inner PE sealing layer (type AF). 2. Metallized films made from up to three layers of aluminium coated PET film and an inner PE sealing layer (type MF) 3. Polymer films with different plastic layers laminated to each other. These films are only useful if the required lifetime is not too extensive or special getters are integrated.

Figure 2.5: Three types of envelope

2.2.3. Getters, desiccants and opacifiers To maintain the inner vacuum is very important for the service life of VIPs. It is often use 6


getters to continuously adsorb the gasses and the desiccants to adsorb water vapour in VIP core material in order to prevent the increase of both gas and vapour pressure, as a result to increase the service life [17]. Some core materials of VIPs can fulfil the function of getters and desiccants, but not all of them. This makes it important to add these chemicals to the core. Opacifiers are the chemicals added to the core material such as fumed silica to make it opaque to infrared and thus to reduce the radiative conductivity to a low level. However, the main drawbacks of these chemicals added are that they decrease the thermal resistance and increase the manufacturing costs.

2.3. VIP in building applications VIPs can be typically used in roofs, walls, and floors for both in new constructions and in retrofitting applications as shown in Appendix 1. A well-presented technical drawing of locations and types of VIPs should be installed is essential before construction starts since the panels cannot be placed near the construction site. This section introduces VIPs in building applications and some practical cases.

One of the major usages of VIPs is in exterior walls, both in light weighted timber frames and in heavy concrete constructions. VIPs can be used on the exterior and interior of external walls. Although it is easier to integrate VIPs in new constructions since the designer is in control of all skill requirements and successful installations, the most common way of using VIPs now is on the external faces of the existing walls. In addition, VIPs can also be integrated in a structural sandwich panel to increase the protection of them [18]. One case of VIP insulated new buildings is shown in Figure 2.6 which is located in Bersenbr端ck, Germany. In order to protect VIPs from damage, they are encapsulated all sides in 20mm EPS. The average U-value is 0.15W/m2K was achieved by adding an additional 80mm EPS layer, which made the wall another140mm thicker. However, by using VIPs, it also half the thickness needed with conventional insulations to reach the same thermal property [18].

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Figure 2.6: House insulated with 20mm VIP encapsulated in 20mm EPS which were attached by a rail system (Photo: Zwerger and Klein, 2005)

Figure 2.7 shows a gable wall of an existing house was retrofitted using VIPs. The project is done in 2000 in Nuremberg, Germany. The system for attaching VIPs was based on a system called rail system. The 15 mm VIPs were integrated between 35mm thick horizontal plastic rails that were fastened in an 35mm EPS layer [19]. The U-value of the wall was improved from 0.7 to 0.19 W/m2K.

Figure 2.7: A building retrofitted on the exterior with 15mm VIP using a special plastic rail system (Photo: ZAE Bayern)

VIPs are interesting to use in floors where the thermal resistance requirements are high, and construction thickness is limited. VIPs can be used to increase efficiency of roof heating system if the system is used in the building. Figure 2.8 indicates a floor is insulated

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by 20mm VIPs in order to increase the floor heating system efficiency. The U-value is decreased from 0.43 to 0.15 W/m2K [20].

Figure 2.8: The floor of a gym was retrofitted with 20mm VIP which decreased the U-value from 0.43 to 0.15 W/m2K

Recently, VIPs have been proposed to use as prefabricated attic access panels and stairways [21]. VIPs can also be used to increase thermal resistance of flat roofs and terraces. In addition, VIPs are able to be used in doors and dormer windows as well. Figure 2.9 shows an existing roof in Switzerland was insulated with 10mm VIPs covered by a water protection layer. Under this circumstance, the aging effect is essential which is found to follow the data derived in lab testing with 80% relative humidity. The thermal conductivity of the VIPs is expected to increase from 0.0029W/mK to about 0.0074 W/mK [21].

Figure 2.9: A flat roof equipped with VIP covered by a water repellent layer

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CHAPTER 3

COMPARE VIPS WITH OTHER INSULATIONS

3.1. Introduction to other building insulations 3.1.2. Conventional insulations Conventional insulations are the building insulations widely used nowadays, also known as traditional insulations, which are usually made from petrochemicals or biological products. The examples of these insulations can be glass or mineral wool, expanded or extruded polystyrene (EPS/XPS), cork board, straw bale, sheepâ€&#x;s wool and etc. The wide usage of these insulations is because not only their better thermal resistances than other alternatives, but they are also easy to approach and inexpensive to produce and install. However, the thermal performances of these materials are not so good; usually their thermal conductivities are between 0.03 and 0.05W/mK. Now, the weaknesses of conventional thermal insulations and solutions emerge as thermal insulation requirements keep increasing. At this circumstance, conventional insulations require rather thick building envelopes. A thicker envelope brings new challenges with both building physics and practice. In addition, such thick structures are less cost effective in places where the area is restricted. Ranges of thermal conductivities of some examples are listed in Table 3.2, and thicknesses of variety insulation products meet building regulations are shown in Figure 3.1. Another drawback some organic thermal insulation materials may bring is health concerns and hazards especially in case of fire, although they are safe in their intended use. For example, polyurethane (PU) releases very poisonous hydrogen cyanide (HCN) and isocyanates, when burning [22].

3.1.3. Advanced insulations Vacuum technology is not the only solution to achieve a high level of thermal insulation. Except vacuum technology, advanced thermal insulation technologies also include aerogels, gas-filled panels (GFPs) and phase change materials (PSM). Aerogels are nanoporous materials that exhibit extraordinary physical and chemical properties, such as low heat conductivity. This kind of high porosity dried gels were discovered in the 1930s by Kistler

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[23]. The high porosity also makes aerogel low density and low mechanical strength. Although its skeleton density is about 2200kg/m 3, the bulk density is as low as 3kg/m3. For building applications, an aerogel based insulation material is currently developed by Aspen Aerogels, Inc. called Space loft速 [24]. It is an opaque flexible aerogel blanket has a thermal conductivity of 13.1 mW/mK in thickness of 10mm [25]. Although the aerogel material has a higher thermal conductivity but it has its own benefit over VIPs. For example, the aerogel blanket can be cut into any sizes to fit any situations. In addition, it has no hazard of thermal bridge, envelope-related problems and has less ageing problem compared to VIPs. Also GFPs is another advanced thermal insulation material, which work on a similar principle to VIPs [26]. It is filled with low thermal conductivity gases such as argon, krypton, and xenon, in GFPs rather than a vacuum is applied [27]. These gases should meet a number of requirements and considerations. The first one is low thermal conductivity, then the gas should not be unstable and greenhouse gas [26]. However, until now no commercial products for building applications have been produced and their performance, effectiveness, and durability are questionable so far.

In addition to these high thermal insulations, VIPs can also be improved and some other vacuum-based materials are now developing. New concepts like vacuum insulation materials (VIMs), nano insulation materials (NIMs) gas insulation materials (GIMs), dynamic insulation materials (DIMs) and etc. are now introduced to the public [22]. The study for future insulation materials is massive and no more details will be given here.

3.1.4. Performance comparison of insulations Unfortunately, until now there is no single insulation material or solution that is capable to fulfil all requirements and optimum for all the properties. Therefore, circumstances and specifications should be considered when choosing insulations for different projects. Except some general properties of the insulations such as thermal conductivity, cost, density, and stability, these criteria can also include operating temperature range, moisture

11


resistance, resistance to animal/chemical attack, ease of use, toxicity, fire property, and etc. Some properties of insulation materials are listed in Table 3.1, and their ranges of thermal conductivities are listed in Table 3.2. The contents are mostly found from the insulation materials chart of Energy Saving Trust [28] and some are adapted by data from different manufactories. It is worth to state that some data are not found and accuracy problems may exist due to the development of the products.

Density

Fire resistance

Price for d=100mm â‚Ź/m3

kg/m3 VIPs*

Silica

powder

170-200

Non-flammable

4000-5000

core

Aerogel

Note

rigid,

fragile,

high

thermal

performance, high price,

PU core

60-70

Non-flammable

3000-4000

-

100-150

Good fire resistance

500-1000

losts of dust and particles when handling

GFPs

-

5

Non-flammable

-

PU

PU with pentane

32

Flammable

250-300

Flammable

250-300

PU with CO2 EPS

20-30

Flammable

150-200

XPS

30-38

Flammable

350-400

Mineral

Glass wool

16-80

Non-flammable

80-250

wool

Stone wool

32-160

Non-flammable

80-250

Biological

Cork

120

Flammable

300

products

Sheepâ€&#x;s wool

25

Flammable

-

Straw bale

160-420

Flammable

-

PS

releases poisonous gas when burning

releases poisonous gas when burning

flexible, low density, sTable

eco-friendly and natural products

Table 3.1: Properties of some insulation materials *Some thermal properties and prices of products from Va-Q-Tec are listed in Appendix 2

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VIPs

Thermal conductivity

0

Silica powder core

0.003-0.005

PU core

0.007-0,009

0.01

0.02

Aerogel

-

0.013-0.015

GFPs

-

0.01

PU

PU with pentane

PS

0.04

0.027

0.035

EPS

0.033 0.025

0.044

Stone wool

0.030

0.040

Sheepâ€&#x;s wool

0.08

0.035 0.030

products

0.07

0.04

Glass wool

Cork

0.06

0.03

PU with CO2

Biological

0.05

0.022

XPS Wool and fibre

0.03

0.042 0.039

Straw bale

0.05 0.05 0.08-0.15

Table 3.2: Insulation materials thermal conductivities chart

In addition to these numbers, it will be clearer to show the insulation thicknesses required for a wall to meet the regulations of Approved Document L. The changes of regulations from 2006 to 2010 for U-value required in buildings in UK have been compared in Table 1.1. Simple calculations are made to determine the thicknesses of different insulations to achieve U-value of 0.25W/m2K. Although calculation of U-value is complicated process which is related to environmental aspects, one simple process will be used here based on the equation: U_value =

1 Rđ?‘ đ?‘– + đ?‘…đ?‘ đ?‘œ + đ?‘…đ?‘–đ?‘›đ?‘ đ?‘˘đ?‘™đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘›

Where, Rsi is thermal resistance of internal surface, which is assumed to be 0.13m2K/W as given in BS EN ISO6946 [29] Rso is thermal resistance of outside surface, which is assumed to be 0.04m2K/W as given in 13


BS EN ISO6946 [29] đ?‘…đ?‘–đ?‘›đ?‘ đ?‘˘đ?‘™đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› =

thickness đ?‘‘ = thermal conductivity đ?œ†

thickness (mm)

The results are shown in Figure 3.1. 600 550 500 450 400 350 300 250 200 150 100 50 0

Figure 3.1: Insulation thickness to achieve U-value of 0.25 W/m2K

3.2. Advantages and disadvantages The first benefit of VIPs is the reduction of the thickness of the insulation layers to achieve the same thermal properties compared to traditional thermal insulation material in building application. The necessary building insulation thickness may be decreased with a factor of 5 up to 10, as a result, it increases the floor area [3]. VIPs are also useful in retrofitting of old buildings. In addition, a lower operating temperature is required to increase thermal performance, which is beneficial in cold areas.

However, VIPs also have a lot of disadvantages. The most serious limitation is they are very fragile and need to be protected against puncture of the foil. In addition, their service life is not guaranteed and replacement may be required [30]. Increased structural thermal bridging due to the envelope need also carefully considered. Furthermore, VIP products cannot be cut to fit as with conventional insulation as this would destroy the vacuum [31]. Therefore, VIPs 14


in non-standard sizes must be made to order, which also increases the cost. Main benefits and drawbacks of both VIPs and conventional insulations are listed in Table 3.3.

VIPs

Conventional insulation materials

Advantages  High thermal insulating performance

 Relatively low insulating performance

 Efficient floor area savings

 Cost is low

 Applicable to refurbish existing

 Used and tested for long time  Known environmental performance

buildings with high restrictions  Lower operating temperature Disadvantages  Very fragile and protection for puncture

 Increasing insulation thickness

required

encroaching on living space

 Initial cost is high

 Risks of contamination materials

 Limited service life and require

 Maybe flammable and release

replacement

poisonous gas when burning

 Thermal bridging effect due to the envelope  Cannot cut on-site  Less suitable for timber wall structures Table 3.3: Advantages and disadvantages of VIPs and conventional insulations

CHAPTER 4

EXPERIMENTAL DESIGN AND PROCEDURES

4.1.Introduction to the experiment The purpose of the experiment is to test and compare the performances of four insulation materials: Vacuum Insulation Panel (VIP), aerogel, EPS and glass wool. These four dimensionally same insulation panels are attached on a wooden frame, which forms a testing box with additional two wooden boards on both top and bottom. The main principle to 15


measure their insulation performances is to compare the temperature differences between inside and outside the box and to determine their abilities of thermal resistance. A temperature-controlled heater is put on the middle of the bottom inside the testing box to guarantee the inside area temperature is homogeneous and exact 35℃. The outside air temperature is that in the laboratory, which is about 17℃ although may vary through time. According to the recorded data from the experiment, we can find that VIP has the best thermal resistance performance, while the glass wool has the worst.

4.2.Description of theory It is easy to understand that whenever a temperature gradient exits in a solid medium, heat will flow from the high temperature to the low temperature, which is known as heat conduction. In the experiment, all the heat transferred from inside to outside can be said through heat conduction. The rate at which heat is transferred by conduction through the panels, qk, can be calculated through Fourierâ€&#x;s Low of conduction: đ?‘žđ?‘˜ =

đ??´đ?‘˜ đ?‘™

(đ?‘‡đ?‘œđ?‘˘đ?‘Ą − đ?‘‡đ?‘–đ?‘› )

(4.1)

Where, A is the area through which heat is transferred (m2). K is thermal conductivity which is a physical property of the medium (W/mK). l is the thickness of the medium heat is transferred (m). đ?‘‡đ?‘œđ?‘˘đ?‘Ą and đ?‘‡đ?‘–đ?‘› are temperatures of either sides of the medium (℃). ∆đ?‘‡

To rearrange the Eqn.(4.1) we can have đ?‘žđ?‘˜ = đ?‘™/đ??´đ?‘˜, where l/Ak is equivalent to a thermal resistance Rk that the medium offers to the flow of heat by conduction. Therefore đ?‘…đ?‘˜ =

đ?‘™

(4.2)

đ??´đ?‘˜

In the experiment, I will measure the temperature difference across the insulation. Then, by using the equations above, the heat transferred through the panels and the thermal resistance can be calculated and compared. In addition, although the fact is that thermal conductivity changes through with temperature, I consider here it does not change due to the relatively

16


small change gradient of temperature.

4.3.Description of apparatus There are four main parts consisting the testing apparatus in the experiment: the testing box, thermocouples, a 30W heater, a heating controller and a computer to record temperature. The picture of the whole testing apparatus is shown in Figure 4.1.

4.3.1. Testing box It is the most essential part of the testing experiment. The shape and dimensions of the wooden frame which serves as the core skeleton are shown in Figure 4.2. Two wooden boards are attached on the top and bottom of the frame, and four dimensionally same insulation panels are attached on the other four sides using adhesive. The size of all the four panels is W × L × T = 240mm × 240mm × 26mm . Four insulation panels and the wooden board on the top are adhered by silicone sealant and aluminium tapes. Because some side areas are used for adhering, the effective heat conductive areas for all panels are 220mm × 220mm. The gaps between the five panels and the wooden skeleton are well sealed by silicone sealant, leaving only the wooden panel on the bottom flexible.

Figure 4.1: The whole testing apparatus

Figure 4.2: Core skeleton of the testing box

The materials of the four insulation panels are VIP, aerogel insulation panel, polystyrene and glass wool. The dimensions and thickness of VIP are determined and the initial thermal conductivity is chosen as its thermal property (shown in Table 4.1). The thickness of one 17


aerogel insulation panel is about 6mm. Therefore, I combined tightly four pieces of aerogel insulation panels together to achieve the same thickness as the VIP. However the combined panel is a little thicker than 26mm. Original polystyrene board is very huge and thick one, using a saw I cut a piece of board of suitable size. The piece of glass wool is cut from a big roll. In order to maintain its original lose state, I tried my best not to compress and tear it when processing it into a suitable size and thickness. The properties of these four materials are listed below in Table 4.1. The pictures of the four insulation panels and wooden frame are shown in Figure 4.3. Insulation

Producer

VIP

NanoPore ™ Celotex™ Knauf™

Aerogel Polystyrene Glass wool

Effective conductive area đ?&#x;?đ?&#x;?đ?&#x;Žđ??Śđ??Ś Ă— đ?&#x;?đ?&#x;?đ?&#x;Žđ??Śđ??Ś

thicknes s 26mm

Heat conductivity(W/mK) 0.005

~26mm 26mm 26mm

0.016 0.022 0.044

Table 4.1: Properties and produce companies of the four insulation panels

Figure 4.3: Pictures of the four insulation panels and Figure 4.4: Location of heater and the wooden frame

thermometer

4.3.2. Thermocouples 4 pairs, 8 thermocouples are used in the experiment, connecting the surfaces of panels, a data collector and the computer. 2 thermocouples are attached on both two surfaces of each insulation panels. They are attached by aluminium tapes right on the centre of each surface. 18


The thermocouples are sensitive to the change of temperature and accurately record thermal data every 20 seconds.

4.3.3. Heater The heater used is produced by Pfannenberg™ in Germany. Its type is FLH 030-M, whose rated power is 30W. The heater is located on the centre bottom inside the testing box. It will keep heating the internal area until the inside temperature reaches the setting temperature, and heat again when the internal temperature falls down. Therefore, it needs to be well controlled by a controller which is introduced below.

4.3.4. Heating controller The heater is connected with a heating controller as well as a thermometer. The thermometer is located right in the centre inside the testing box, as shown in Figure 4.4. The thermometer tests the internal temperature and tells the controller when to trun off on the heater to guarantee the internal temperature right at the setting one.

4.4. Experimental procedures The experimental procedure is simple but needs to last long enough until testing readings stabilised. It will take several hours. The completed experimental procedure is listed below. a. Install the whole testing box, adhere thermocouples on both surfaces of four insulation panels, locate the heater and connect to the heating controller and the computer correctly. Record channel numbers of each thermocouple against each panel. b. Set the temperature on the heating controller to 35℃. Before sealing the top wooden board, a list of test readings should be recorded and read in the computer to ensure all the equipment work well, especially every thermocouple. c. After making sure the whole apparatus woks correctly, turn off the heater and seal the top board by silicone sealant completely. d. Set the data recording period into 20 seconds of the data-taken software and turn on the

19


heater and heating controller. e. Write down the time when the internal temperature first reaches 35℃, and check the whole apparatus every half an hour to ensure it works properly. f. After 5 hours or when the temperature of both inside and outside stabilised, turn off the heater and controller, copy data from the computer.

4.5. Results and discussion 4.5.1. Internal surface temperature Internal air temperature reached 35℃ after 25 minutes‟ operation. While the internal surface temperature became stable until the apparatus operates for 70 to 80 minutes. The changing internal surface temperature for each insulation panel is plotted in a same graph in Figure 4.5. The stable internal temperature of glass wool and aerogel insulation panels are almost the same as the heating temperature, 35℃, while that of the VIP is slightly higher. However, the internal surface temperature of the polystyrene board is much higher than the setting temperature and vibrating all the time. Both of the internal surfaces of VIP and Polystyrene panel are covered with aluminium foil, while the other two panels are not. It is strongly suggested that the aluminium foil affects the experiment results.

50 45

PS/C1

Temperature(℃)

40 VIP/C2

35 30

Areogel/C3

25

Glass Wool/C4 Heating Temperature

20 15 10 5 0 0.00

50.00

100.00

150.00 200.00 Time(min)

Figure 4.5: Internal surface temperature

20

250.00

300.00


4.5.2. External surface temperature As said before, the laboratory air temperature is about 17℃, the external surface temperature dependents on both environment temperature and internal heating. Therefore, the differences between each insulation materials are significant (shown in Figure 4.6). It is clear that after the temperature stabilised, the external surface temperatures of glass wool and polystyrene board increase the most and that of VIP even almost does not change. The

40 35 PS/H1

Temperature(℃)

30

VIP/H2

25

Aerogel/H3

20

Glass Wool/H4

15

Heating Temperature Envi Temperature

10 5 0 0.00

50.00

100.00

150.00 200.00 Time(min)

250.00

300.00

external surface temperature aerogel insulation panel changes moderately. Figure 4.6: External surface of temperature

4.5.3. VIP thermal performance As can be read from the Figure 4.7, the internal surface temperature reaches stable state after 70 minutesâ€&#x; operation. Therefore the temperature recordings after 70 minutes can be used to calculate the average external and internal surfaces temperature. The average external temperature (Tout) is 36.8℃ which is about 2℃ higher than the internal heating temperature. And the average internal surface temperature (T in) is 17.4℃ which is about the same as the environment temperature. Therefore the temperature difference (ΔT) is 19.4℃. According to Eqn.(4.1) , the heat transfer rate by conduction (qk) can be calculated as: đ?‘žđ?‘˜ =

đ??´đ?‘˜ 0.22 Ă— 0.22 Ă— 0.005 (đ?‘‡đ?‘œđ?‘˘đ?‘Ą − đ?‘‡đ?‘–đ?‘› ) = Ă— 19.4đ?‘Š = 0.18đ?‘Š đ?‘™ 0.026

The thermal resistance to conduction heat transfer (R k) can be calculated through Eqn.(4.2): 21


đ?‘™

0.026

đ?‘…đ?‘˜ = đ??´đ?‘˜ = 0.22Ă—0.22Ă—0.005 = 107.4đ??ž/đ?‘Š 40 Temperature(℃)

35 30 VIP/In

25 20

VIP/Out

15 10

Heating Temperature

5 0 0.00

50.00

100.00

150.00 200.00 Time(min)

250.00

300.00

Figure 4.7: VIP surfaces temperature

4.5.4. Aerogel thermal performance The internal surface temperature reaches stable state also after 70 minutesâ€&#x; operation (shown in Figure 4.8). The average external temperature (Tout) is 34.8℃ which is about the same as the internal environment temperature. And the average internal surface temperature (T in) is 18.8℃ which is about 2℃ higher than the external environment temperature. Therefore the temperature difference (ΔT) is 16.0℃. Using the same procedure, the heat transfer rate by conduction (qk) can be calculated, which is 0.48W. The thermal resistance to conduction heat transfer (Rk) is 33.6K/W. 40

Temperature(℃)

35 30 Areogel/In

25 20

Aerogel/Out

15 10

Heating Temperature

5 0 0.00

50.00

100.00

150.00 200.00 Time(min)

Figure 4.8: Aerogel surfaces temperature

22

250.00

300.00


4.5.5. EPS thermal performance The internal surface temperature reaches relatively stable after 80 minutes‟ operation although it keeps vibrating all the time. It is the most unstable curve among all the experiment results (shown in Figure 4.9). The average external temperature (Tout) is about 41.6℃ which is about 7℃ higher than the internal environment temperature. And the average internal surface temperature (T in) is 20.9℃ which is about 4℃ higher than the external environment temperature. Therefore the temperature difference (ΔT) is 20.7℃. Using the same procedure, the heat transfer rate by conduction (q k) can be calculated, which

Temperature(℃)

is 0.85W. The thermal resistance to conduction heat transfer (R k) is 24.4K/W. 50 45 40 35 30 25 20 15 10 5 0 0.00

PS/In EPS/Out Heating Temperature Envi Temperature 50.00

100.00

150.00 200.00 Time(min)

250.00

300.00

Figure 4.9: Polystyrene surfaces temperature

4.5.6. Glass wool thermal performance The internal surface temperature reaches relatively stable after 70 minutes‟ operation (show in Figure 4.10). The average external temperature (T out) is about 35.0℃ which is almost the same as the internal environment temperature. And the average internal surface temperature (Tin) is 21.5℃ which increases about 4 ℃ than the external environment temperature. Therefore the temperature difference (ΔT) is 13.5℃. Using the same procedure, the heat transfer rate by conduction (qk) can be calculated, which is 1.1W. The thermal resistance to conduction heat transfer (Rk) is 12.2K/W.

23


40

Temperature(℃)

35 30

Glass Wool/In

25 20

Glass Wool/Out

15 Heating Temperature

10 5 0 0.00

50.00

100.00

150.00 200.00 Time(min)

250.00

300.00

Figure 4.10: Glass wool surfaces temperature

4.6. Conclusion The experiment successfully tests four kinds of insulation materials. The data are nice and clear, a table can be listed to compare thermal properties of the four insulation materials, shown in Table 4.2. From the table, it is clear that the insulation performance of VIP is the best, while aerogel, polystyrene ranks the second and third, glass wool is the worst. The thermal resistance of VIP is even 10 times higher than glass wool. Insulation

Heat

Temperature

heat transfer rate

Thermal resistance to

conductivity

difference

by conduction

conduction heat transfer

W/mK

W

K/W

VIP

0.005

19.4

0.18

107.4

Aerogel

0.016

16.0

0.48

33.6

Polystyrene 0.022

20.7

0.85

24.4

Glass wool

13.5

1.1

12.2

0.044

Table 4.2: Thermal properties of the four insulation materials

4.7. Recommendation a. The aluminium foils on the internal surface of VIP and polystyrene board may have affect to the internal surface temperature of the panels as both of their internal surfaces‟

24


temperature increase to higher than 35℃. It is a strange phenomenon as the other two panels without aluminium foils do not appear to increase further when reach setting internal temperature. It is also suggested that the aluminium tapes used to attach thermocouples on panelsâ€&#x; surfaces and combine thin aerogel insulation panels together may also have impact on the results of the experiment. Further works should be done to get rid of this effect. b. The laboratory environment temperature must change during the testing time. Although it may not so significant, a recording is supposed to be done in order to examine impact of the environment temperature on the external surface temperature. The best case is to locate the whole testing apparatus in a place where temperature does not change. c. The tightness of the testing box is not checked before the experiment although a lot of methods have been implemented to seal the gaps between insulation panels and the wooden frame. In addition, the bottom wooden board is not sealed and flexible. Heat may run out of the box and affect the readings of thermocouples. d. The thickness of all four panels may have slightly differences; the exact thicknesses are supposed to taken down before the experiment. In addition, the thicknesses polystyrene panel and glass wool are not homogenous in different directions and parts. Although it is hard to make any difference, more accurate methods can be thought of and taken. e. The experiment time period can be lasted longer and experiment can be done in different environment conditions such as temperature, moisture and air pressure.

CHAPTER 5

SOFTWARE MODELLING OF E.ON HOUSE

5.1. Introduction to the modelling The task of the modelling is to compare a particular houseâ€&#x;s energy consumption which is insulated by VIPs or conventional insulations. Ecotect is chosen to be used to do the modelling based on E.ON 2016 Research House in the University of Nottingham. This is a typical 1930s semi-detached house built in 2008 designed for research to comply with the zero emission target for all new homes built from 2016. This kind of houses was largely

25


built during 1930s and 1960s, which accounts for more than 60% of the housing stock in UK. Thus, it is worthy to study the original thermal performance and improvement of the house. The basic information of the house is listed in Table 5.1, and two face images with solar path diagram are shown in Figure 5.1 and 5.2. Name Surface glazing

E.ON 2016 Research House Location ratio 24%

Nottingham, UK

Plan area

63.8m2/floor

Volume

332.4m3

Hight

2.6m/floor

Population

3 persons

Usage

Dwelling

Table 5.1: Basic information of E.ON House

Figure 5.1: Image of north face

Figure 5.2: Image of south face

In the first step, the overall thermal performance of E.ON House is modelled with its original building materials. Then, all the building construction materials are insulated, and its thermal performance is studied. Two insulations are chosen to be compared here: one is EPS, and the other one is VIPs. Apart from modelling, manual calculations are used to check the accuracy of the software. The aims of the modelling are listed below: a.

To calculate energy savings when all the construction elements are enhanced by EPS or VIPs

b. To compare the thicknesses of different insulations to achieve a particular U-value and space savings by advanced insulation materials 26


c.

To economic analyse the cost efficiency and payback period of using different insulations

5.2. Description of modelling process The first and the most important step of the modelling is to determine construction elementsâ€&#x; materials. These elements are external wall, roof, ceiling, floor, door, and window. It should be pointed out that external wall of the balcony is different from other external wall; internal walls are not considered in this case; internal ceiling and roof will be considered to be the same element for simple purpose; doors and windows will not be changed or enhanced during the whole process. The choice of the materials for both predesign and redesign, and some of their properties are listed below: External wall U-value: 1.45W/m2K

Original

Admittance: 4.97 W/m2K Solar absorption: 0.864 110mm brick-50mm air gap-110mm brick-10mm

Thickness:280mm

plaster (Outside-Inside) EPS

U-value: 0.3W/m2K

enhanced

Admittance: 4.95 W/m2K Solar absorption: 0.864 110mm brick-100mm EPS-110mm brick-10mm

Thickness:330mm

plaster (Outside-Inside) VIPs

U-value: 0.2W/m2K

enhanced

Admittance: 5.01 W/m2K Solar absorption: 0.864 80mm brick-10mm EPS-20mm VIPs-10mm EPS -80mm brick-10mm plaster (Outside-Inside)

27

Thickness:210mm


Balcony wall U-value: 2.71W/m2K

Original

Admittance: 4.35 W/m2K Solar absorption: 0.1 10mm concrete-110mm brick masonry

Thickness:130mm

medium-10mm plaster(Outside-Inside) EPS

U-value: 0.28W/m2K

enhanced

Admittance: 4.95 W/m2K Solar absorption: 0.1 10mm concrete-110mm EPS-110mm brick masonry

Thickness:240mm

medium-10mm plaster(Outside-Inside) VIPs

U-value: 0.2W/m2K

enhanced

Admittance: 5.03 W/m2K Solar absorption: 0.1 10mm concrete-10mm EPS-20mm VIPs-10mm

Thickness:140mm

EPS-80mm brick masonry medium-10mm plaster(Outside-Inside)

Roof U-value: 2.76W/m2K

Original

Admittance: 0.98 W/m2K Solar absorption: 0.548 50mm clay tiles-75mm air gap-10mm plaster(Outside-Inside)

28

Thickness:135mm


EPS

U-value: 0.16W/m2K

enhanced

Admittance: 1.00 W/m2K Solar absorption: 0.548 50mm clay tiles-200mm EPS-75mm air gap-10mm

Thickness:335mm

plaster(Outside-Inside) VIPs

U-value: 0.20W/m2K

enhanced

Admittance: 0.98 W/m2K Solar absorption: 0.548 50mm clay tiles-10mm EPS-20mm VIPs-10mm

Thickness:175mm

EPS-10mm plaster(Outside-Inside)

Ground base course U-value: 0.46W/m2K

Original

Admittance:5.27W/m2K Solar absorption: 0.467 1500mm soil-150mm concrete(Outside-Inside)

Thickness:1650mm

EPS

U-value: 0.2W/m2K

enhanced

Admittance:5.39W/m2K Solar absorption: 0.467 Thickness:1750mm

1500mm soil-100mm EPS-150mm concrete(Outside-Inside) VIPs

U-value: 0.15W/m2K

enhanced

Admittance:5.39W/m2K Solar absorption: 0.467 1500mm soil-10mm EPS-20mm VIPs-10mm EPS-150mm concrete(Outside-Inside)

29

Thickness:1690mm


Ceiling & floor U-value: 2.67W/m2K

Original

Admittance: 3.57 W/m2K Solar absorption: 0.1 10mm plaster-75mm cement screed-25mm wood oak

Thickness:110mm

white live(Outside-Inside) EPS

U-value:0.24W/m2K

enhanced

Admittance: 3.05 W/m2K Solar absorption: 0.1 10mm plaster-75mm cement screed-130mm

Thickness:240mm

EPS-25mm wood oak white live(Outside-Inside) VIPs

U-value:0.20W/m2K

enhanced

Admittance: 3.02W/m2K Solar absorption: 0.1 10mm plaster-75mm cement screed--10mm

Thickness:150mm

EPS-20mm VIPs-10mm EPS-25mm wood oak white live(Outside-Inside)

Timber door

40mm wood pine

Double glass window/door U-value: 3.39W/m2K

U-value: 2.71W/m2K

Admittance: 3.54

Admittance:

W/m2K

0.84W/m2K

Solar absorption: 0.404 Thickness:40mm

6mm standard glass-30mm air gap-6mm standard glass(Outside-Inside)

30

Solar heat gain coeff:: 0.81 Thickness:42mm


Some other assumptions are made the same under all circumstances. Heating and cooling in the house is provided by a full air conditioning system. A total of 3 people are assumed to be living in it, whose activity levels are sedentary. Because the house is for living, people are not always in it. A schedule is made for occupancy and internal gains. Basically, the schedule is arranged as full occupied during weekends, and occupied between 17:00 and 7:00 during weekdays. The other assumptions are listed in Table 5.2. Interna

Clothing ratio

1 clo

Internal

Sensible gain

5W/m2

l design

Humidity

60%

gains

Latent gain

2 W/m2

Air speed

0.1m/s

Infiltratio

Air change rate

1ach

Lighting level

300lux

n rate

Wind sensitivity

0.1ach

Designed temperature range

23-26℃

Table 5.2: Some internal condition assumptions of E.ON House

5.3. Results For interpreting the results, 3 special days are focused: the coldest weekday (15 th January), the coldest weekend (14th January), the hottest day (21st July). 2 cold days are chosen because room heating is more important than cooling in UK. The internal thermal analysis is for ground floor and first floor only. All detailed data can be found in Appendices from 3-A to 3-D. 5.3.1. Modelling results Original building annual energy for heating:17429.3kWh Date

Heating

Fabric

heat Solar

(Wh)

loss(Wh)

gain(Wh)

loss(Wh)

gain(Wh)

14th Jan

118905

137008

772

3029

20361

15th Jan

85210

151707

546

3569

11877

21st July

2951

8374

4582

170

20361

31

heat Ventilation heat Internal

heat


Building enhanced by 100mm EPS insulation annual energy for heating: 4116.3kWh, annual energy for cooling: 2.2kWh Date

Heating

Fabric

heat Solar

heat Ventilation heat Internal

(Wh)

loss(Wh)

gain(Wh)

loss(Wh)

gain(Wh)

14th Jan

35195

53186

659

3029

20361

15th Jan

27444

58822

468

3569

11877

21st July

0

3010

3881

170

20361

heat

Building enhanced by 20mm VIPs insulation annual energy for heating: 4082.2kWh, annual energy for cooling:1.7kWh Date

Heating

Fabric

heat Solar

heat Ventilation heat Internal

(Wh)

loss(Wh)

gain(Wh)

loss(Wh)

gain(Wh)

14th Jan

35202

53191

658

3029

20361

15th Jan

27423

58813

467

3569

11877

21st July

0

3031

3875

170

20361

heat

Building enhanced by 40mm VIPs insulation annual energy for heating: 2041.2kWh, annual energy for cooling:1.0kWh Date

15th Jan

Heating

Fabric

heat Solar

heat Ventilation heat Internal

(Wh)

loss(Wh)

gain(Wh)

loss(Wh)

gain(Wh)

15400

29401

467

3569

11877

Building enhanced by 80mm VIPs insulation annual energy for heating: 74.2kWh, annual energy for cooling:1402.3kWh 15th Jan

-243

14700

467

3569

32

11877

heat


5.3.2. Manual calculation The temperature in Nottingham is always low throughout the year, which results that central heating is used more than half a year. In the house, heat loss is always more significant than heat gain. The heat gains/losses should be divided into four parts as these in the tables before: fabric heat loss, solar heat gain, ventilation heat loss, and sensible heat gain. Among them, only fabric heat loss is related to the changes of insulation materials. After all, this section is used to check the accuracy of the software modelling. Sensible heat gain will not be presented here.

First, the method to calculate the heat gain through fabric and window is based on the Eqn.(5.1) [32]: =

đ??´(đ?‘‡đ?‘œđ?‘˘đ?‘Ą − đ?‘‡đ?‘‘đ?‘’đ?‘ đ?‘–đ?‘”đ?‘› )

(5.1)

Where, = Thermal Transmittance (W/m2 ) đ??´ = a ric or window area(m2 )

The heat losses through fabric and windows of each floor can be calculated below. The internal temperature is assumed to be 23℃, and lowest outside temperature on 15th January is between 7:00 to 8:00, which is -5℃. It should be noticed that temperature difference inside and outside the ceiling of the second floor is smaller than other circumstances. It is because that there is a roof as well as a big space outside the ceiling, which can be seen as an insulation layer. The glazing area includes both double glazed windows and doors. The calculations of both original building and VIPs enhanced building are shown in Table 5.3 and 5.4. Original Building (7:00 to 8:00 on 15th January) Ground Floor

U value (W/m2K)

Area (m2)

ΔT (K)

Q(W)

External wall

1.45

62.2

28

2525.32

Balcony wall

2.71

3.7

28

280.76

33


Glazing Area

2.71

17

28

1289.96

Floor

0.46

63.8

13

381.52

Timber door

3.39

1.65

28

156.62 4634.18

Subtotal First Floor External wall

1.45

67.3

28

2732.38

Balcony wall

2.71

3.7

28

280.76

Glazing Area

2.71

16.2

28

1229.26

Ceiling

2.67

62.3

20

3326.82

Subtotal

7569.21

Total

12203.39

Table 5.3: Manual calculation of fabric heat loss of original building 20mm VIPs enhanced building (7:00 to 8:00 on 15th January) Ground Floor

U value (W/m2K)

Area (m2)

ΔT (K)

Q(W)

External wall

0.2

62.2

28

348.32

Balcony wall

0.2

3.7

28

20.72

Glazing Area

2.71

17

28

1289.96

Floor

0.15

63.8

13

124.41

Timber door

3.39

1.65

28

156.62 1940.03

Subtotal First Floor External wall

0.2

67.3

28

376.88

Balcony wall

0.2

3.7

28

20.72

Glazing Area

2.71

16.2

28

1229.26

Ceiling

0.2

62.3

20

249.20

Subtotal

1876.06

Total

3816.09

Table 5.4: Manual calculation of fabric heat loss of 20mm VIPs enhanced building 34


Second, solar heat gain is the main source of the building heat gain, which can be calculated through the equation below: olar ain = ( olar cooling load × la ing area + olar cooling load × la ing area

+ olar cooling load × la ing area

+ olar cooling load × la ing area ) × orrection actor There are four directions of building faces can get sunlight during the daytime, the glazing area of each orientation is shown in Table 5.5. The correction factor is assumed to be 0.6 according to CIBSE Guide A [33]. Orientation

Ground Floor (m2)

First Floor (m2)

Total

North

6.7

5.8

12.5

East

1.2

1.2

2.4

South

5.5

4.5

10.0

West

3.6

4.7

8.3

Table 5.5: Glazing area in each orientation

In accordance with the solar cooling loads for fast response building with exposed single clear glazing in Northwest England (Table 5.21 of CIBSE Guide A, shown in Appendix 4). I process the results for the day of 29th January in Table 5.6, the detailed process is shown in Appendix 5. 730

830

930

1030

1130

1230

1330

1430

1530

1630

1730

North(W)

75

137.5

225

350

437.5

487.5

500

437.5

337.5

200

125

East(W)

57.6

192

364.8

453.6

374.4

170.4

139.2

115.2

96

72

57.6

South(W)

700

1100

1880

3100

4300

4710

4770

4070

2840

1720

1000

West(W)

157.7

199.2

257.3

340.3

398.4

498

697.2

1328

1502.3

1162

564.4

Total(W)

990.3

1628.7

2727.1

4243.9

5510.3

5865.9

6106.4

5950.7

4775.8

3154

1747

After correction(W)

594.18

977.22

1636.26

2546.34

3306.18

3519.54

3663.84

3570.42

2865.48

1892.4

1048.2

Table 5.6: Solar heat gain of the house on 29th January

35


Third, heat loss occurs due to air ventilation and infiltration because of the temperature different between inside and outside air. In this part, the air infiltration is ignored because of its tiny impact. We use the equation below to calculate ventilation heat loss between 7:00 and 8:00 on 15th January as an example. đ?‘’đ?‘›

=

đ?‘?

(đ?‘‡đ?‘œđ?‘˘đ?‘Ą − đ?‘‡đ?‘‘đ?‘’đ?‘ đ?‘–đ?‘”đ?‘› )

Where, = pecific heat capacity of air = 1.005k /kgk = density of air = 1.29kg/m v = volume flow rate (m /s) The air flow rate assumed in this case is 1ach. The volume of E.ON House is about 332.4m3, so v =

2. 600

= 0.09 đ?‘š / . Ventilation heat loss at that time is: |

đ?‘’đ?‘› |

=

|1.005 Ă— 1.29 Ă— 0.09 Ă— (−5 − 23)| = 3.3đ?‘˜đ?‘Š.

5.4. Compare and discussion 5.4.1. Software vs. manual calculation A big discrepancy is revealed by comparison of software modelling and manual calculation. First, for fabric heat loss, a nearly 100% difference exists between software and manual calculation results of the original building. An about 50% difference exists for VIPs enhanced building. After observation, it is concluded that the reason may be the software averages the results all day long. Because the fabric heat loss delivered by the software suggests similar every hour, however, the temperature differences between inside and outside during daytime on weekdays are not that much compared to the time when the house is occupied. Anyway, the final result of daily fabric heat loss is similar between software and manual calculation result.

Second, the results of software modelling and manual calculation of solar heat gain have a significant of about 5 timesâ€&#x; difference. The hourly heat gain/loss of 29th January is shown in Appendix 3. The reason may because the software considers direct and diffuse solar heat 36


gain separately. The manual calculation is too simple and not to be used afterward.

Third, the difference of ventilation heat loss between software and manual calculation results is even more sensitive, which is about 15 timesâ€&#x; difference. One reason is the same with one of the fabric heat loss: software averages results throughout a day. Apart from this reason, the difference gap is still too big. Overall, the software modelling results are more reliable.

5.4.2. Space saving Space saving mainly results from the change of thickness of the external wall. It is assumed that the external configuration does not change, and the internal spacing savings are calculated by multiplying perimeter of the house and the difference of wall thickness. The thicknesses of external walls are listed in Table 5.7 and 5.8. Original(mm) EPS enhanced(mm)

20mm VIPs enhanced(mm)

Perimeter(m)

External wall

280

330

210

28.6/floor

Balcony wall

130

240

140

4.7/floor

Table 5.7: Thicknesses of external walls and perimeter 20mm VIPs (mm)

40mm VIPs (mm)

80mm VIPs (mm)

Perimeter(m)

External wall

210

230

270

28.6/floor

Balcony wall

140

160

240

4.7/floor

Table 5.8: Thicknesses of external walls and perimeter

After calculation, EPS enhanced house uses another 3.9m 2 more of the floor space, while 20mm VIPs enhanced house saves 3.9m2 compares with the original building. Furthermore, the 40mm VIPs enhanced house saves 2.6 m2, 80mm VIPs enhanced house saves 0.5 m2.

5.4.3. Economic analysis According to the price of each insulation listed in Table 3.1 and Appendix 2, the initial 37


costs of all circumstances can be calculated (see Table 5.9). The total insulation area of the house is 326.8m2. The initial costs only stand for the insulation materials costs. It is also assumed that the house is heating by a gas boiler whose efficiency is 95%, nature gas price is 0.045€/kWh, CO2 emission per kWh is 0.89kg/kWh. It is also supposed that energy price does not change every year, and the maintenance and replacement fees are all ignored. The degradation and ageing effects of insulation materials are not considered here as well. Initial cost

Annual heating

Installation

Simple payback

CO2 saving

energy saving

cost

period

(€)

(€)

(€)

(years)

(tones/year)

EPS enhanced

6536

630.6

2000

13.5

11.9

20mm VIPs enhanced

28144

632.2

3000

47.5

11.9

40mm VIPs enhanced

56288

738.8

3000

80.2

13.7

80mm VIPs enhanced

112576

832.1

3000

138.9

15.5

Table 5.9: Initial costs and payback period of each case

5.5. Conclusion 100mm EPS enhanced

3.9m2 space waste

13313kWh heating energy saved(76.4%)

13.5 years payback period

20mm VIPs enhanced

3.9m2 space saving

13347kWh heating energy saved(76.6%)

47.5 years payback period

40mm VIPs enhanced

2.6m2 space saving

15388kWh heating energy saved(88.3%)

80.2years payback period

80mm VIPs enhanced

0.5m2 space saving

17355kWh heating energy saved(99.6%)

138.9 years payback period

Figure 5.3: Key conclusion of each case

38


Some core results are shown in Figure 5.3 above: four sets of modelling have been done. For the first and second modelling, the thermal performances of the house after enhanced by 100mm EPS and 20mm VIPs are similar. It means more than 76% of heating energy used in E.ON House can be reduced if it is retrofitted or rebuilt based on 2010â€&#x;s building regulations. However, if the building is insulated by EPS, 3.9m2 space will be wasted as construction elements which accounts for about 4% of the total floor area. On the contrary, 3.9m2 space will be saved compared to the original house if the house is insulated by 20mm VIPs. Nevertheless, VIPs is much more expensive than EPS, which implies a much longer payback period. When we use a thicker VIPs to insulate the house, more energy is saved due to low construction fabric heat loss which includes walls, floors, and ceilings. As no changes have been made to the windows, energy becomes harder to save after 40mm VIPs insulation. As the results shown, more than 99% of the heating energy can be saved when the house is insulated by 80mm VIPs, while more cooling energy is needed. In other words, the house can rely on internal heat gain and solar heat gain to heat itself, and sometimes heat gain is too much to maintain a comfortable indoor environment. In Nottingham, house cooling can be achieved by passive cooling methods such as simply open windows. Therefore, energy used for cooling will be much less than theory. In my point of view, 100mm EPS insulation is good enough for E.ON House in this case after fully consideration. Although thicker walls need to be constructed, less investment is required. VIP insulation is more space-saving, but the installation id more complicated and regular maintenance should be guaranteed.

Furthermore, both software modelling and manual calculation have their own limitations. We cannot totally rely on data derived from either method to make a final decision. Ecotect is more accurate than manual calculation in this case, so data from modelling are used. Nevertheless, more advanced software is supposed to further use. In the section of space saving and economic analysis, a lot of assumptions are made and some factors are ignored. Further studies can be made to increase the accuracy.

39


CHAPTER 6 CONCLUSIONS Vacuum insulation panel (VIP) is one of the thermal performance materials nowadays whose thermal insulation performance is about 5 to 10 times better than conventional materials. This fact has been checked by a successful lab testing which revealed that heat transfer rate by conduction of VIP is about 2.7 times less than aerogel, 4.7 times less than EPS, and 6.1 times less than glass wool under the same thickness. In the testing, an electric heater was placed inside the testing box to ensure a temperature of 35℃. Although all internal surface temperatures of the four testing materials increase to equal or more than 35 ℃ , the external surface temperature of the VIP almost remains the same as environmental temperature. However, the external surface temperature of aerogel increases 2℃, EPS increases 4℃, glass wool increases 6℃.

The Ecotect modelling results indicate that although VIP can achieve a very good thermal performance in E.ON House with slim construction elements, initial cost is still high. To compare with EPS insulation, about 8m2 floor area can be saved if 20mm VIP insulations are used to meet building regulations of 2010. However, the VIP insulations‟ payback period is about 3.5 times longer than EPS‟s. In my point of view, EPS insulated construction may be more applicable in an area where space is not very cost. To further illustrate, 88.6% of heating energy can be saved when 40mm VIP insulations are used, and 99.3% energy saving when 80mm VIP insulated. Under these circumstances, the major heat loss changes to be through windows and infiltration from fabric heat loss. Nearly all year round, sensible heat gain is enough to maintain a required internal temperature. Sometimes even passive cooling should be considering. Due to the limitations of Ecotect, a more advanced software is required for further study.

Like a recent report written by BRE Trust concluded that, in terms of a conventional economic assessment, the construction of new zero-carbon buildings is not cost-effective

40


[34]. There are a lot of cost-effective energy saving strategies that could be achieved by improving existing buildings. Similarly, the UK governmentâ€&#x;s Low-carbon construction report indicated the improvement of existing house or buildings to be a priority over renewable energy solutions [35].Therefore, refurbishment, particularly for those buildings hard to treat properties with solid walls will increase the demand for new and innovative solutions. VIP insulation is an applicable solution for any extreme examples. The main benefit of the panel has been introduced before is: it can offer a high thermal resistance in buildings with very slim construction structures. However, some main obstacles such as, thermal bridge effect and degradation of thermal performance through time are still existing. In addition, VIP is expansive, fragile and not flexible. Possible solutions should be found out or new insulation materials should be introduced.

41


REFERENCES [1] Baetens, R., Jelle, B.P. & Thue, J.V. (2010), "Vacuum insulation panels for building application: A review and beyond", Energy and Buildings, vol. 42, no. pp. 147-172.

[2] Brunner, S., Stahl, T. & Wakili, K.G. (2012), "An example of deteriorated vacuum insulation panels in a building facade", Energy and Buildings, vol. 54, no. pp. 278-282.

[3] Johansson, P. (2012), "Vacuum insulation panels in buildings", Report in Building Physics, Department of Civil and Environmental Engineering, Chalmers University of Technology, Sweden

[4] Department for Communities and Local Government (DCLG). (2010), The Building Regulations: Approved Document L: Conservation of fuel and Power. London, DCLG [5] Roche, P. L. (2012), Carbon-neutral architectural design. CRC Press, Boca Raton, FL. [6] Ghazi, K., Bundi, R., Binder, B. (2004), “Effective thermal conductivity of vacuum insulation panels”, Building Research and information, vol. 32, pp. 293-299

[7] Willems, W.M. & Schild, K. (2005), "The next generation of insulating materials: Vacuum insulation", Report in Building constructions and building physics, Ruhr-University Bochum

[8] Weinläder, H. (2010), VIG - Vacuum Insulation Glass / ProVIG - Production Technology for Vacuum Insulation Glass. Available from: ZAE Bayern, Web site: http://www.zae.uni-wuerzburg.de/english/division-2/projects/vig.html [Accessed: November 10, 2012]. [9] Wilson, A. (2009), Vacuum-Insulated Windows. Available from: Green Building Advisor, Web site: http://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/vacuum-insulated-w 42


indows [Accessed: November 3, 2012].

[10] Livesey, K., Suttie, E., Scovell, K., & Thielmans, W. (2013), Advanced thermal insulation technologies in the built environment, BRE IP4/13, Garston, Watford

[11] Bouquerel, M., Duforestel, T. & Baillis, D. (2012), "Heat transfer modeling in vacuum insulation panels containing nanoporous silica-A review", Energy and Buildings, vol. 54, no. pp. 320-336.

[12] Kwon, J.S., Jang, C.H. & Jung, H. (2009), "Effective thermal conductivity of various filling materials for vacuum insulation panels", International Journal of Heat and Mass Transfer, vol. 52, no. pp. 5525-5532.

[13] Alam, M., Singh, H. & Limbachiya, M.C. (2011), "Vacuum insulation panels for building construction industry- A review of the contemporary developments and future directions", Applied Energy, vol. 88, no. pp. 3592-3602.

[14] Wakili, K.G., Stahl, T. & Brunner, S. (2011), "Effective thermal conductivity of staggered double layer of vacuum insulation panels", Energy and Buildings, vol. 43, no. pp. 1241-1246.

[15] Bouquerel, M., Duforestel, T. & Baillis, D. (2010), "Transfer modeling in gas barrier envelopes for vacuum insulation panels-A review", Energy and Buildings

[16] Nussbaumer, T., Wakili, K.G. & Tanner, C. (2006), "Experimetal and numerical investigation of the thermal performance of a protected vacuum insulation system applied to a concrete wall", Applied Energy, vol. 83, pp. 841-855. [17] Jung, H., Jang, C.H. & Yeo, I.S. (2012), "Investigation of gas permeation through Al-metallized film for vacuum insulation panels", International Journal of Heat and Mass Transfer, vol. 56, pp. 436-446. 43


[18] FHBB, EMPA, ZAE-Bayern, & et al. (2005) Vacuum insulation in the building sector, IEA/ECBCS Annex 39, Available from: ECBCS, Web site: www.ecbcs.org/docs/Annex_39_Report_Subtask-B.pdf‎‎[Accessed: January 3, 2013].

[19] Fricke, J., Heinemann, U., and Ebert, H. P. (2008). Vacuum insulation panels : From research to market. Vacuum, vol. 82(7), pp. 680-690. [20] Tenpierik, M. J., Cauberg, J. J. M., & Thorsell, T. I. (2007). “Integrating vacuum insulation panels in building constructions: an integral perspective”, Construction Innovation, vol. 7(1), pp. 38-53. [21] Simmler, H., Brunner, S. (2005), “Vacuum insulation panels for building application: Basic properties, aging mechanisms and service life”, Energy and Buildings, vol. 37, pp. 1122-1131. [22] Jelle, B.P., Gustavsen, A. & Baetens, R. (2010), “The path to the high performance thermal building insulation materials and solutions of tomorrow”, Building Physics, vol. 34, no. 2, pp.99-123 [23] Kistler, S. S.(1931), Coherent expanded aerogels and jellies, Nature, vol. 127, no. 3211, pp. 741 [24] Spaceloft® Safety Data Sheet. (2009), Available from: Aspen Aerogels, Web site: http://www.aerogel.com/products/pdf/Spaceloft_MSDS.pdf [Accessed: January 3, 2013].

[25] Baetens, R., Jelle, B.P. & Gustavsen, A. (2011), "Aerogel insulation for building application: A state-of-the-art review", Energy and Buildings, vol. 43, pp. 761-769.

[26] Baetens, R., Jelle, B.P., Gustavsen, A., & Grynning, S. (2010), " Gas-filled panels for building applications: A state-of-the-art review ", Energy and Buildings, vol. 42, pp. 44


1969–1975. [27] Griffith, B. T., Arashteh, D., & Turler, D. (1995) “Gas-filled panels: an update on applications in the building thermal envelope”, Conference Paper of BETEC Fall Symposium, Superinsulations and the Building Envelope, Washington, DC, USA [28] Energy Saving Trust (EST). “Insulation materials chart: thermal properties and environmental ratings”, CE71, London, EST, 2004

[29] Anderson, B. (2006) Conventions for U-value calculations, BRE Scotland, BRE 443, Bracknell, IHS BRE Press [30] Kwon, J.S., Jung, H. & Yeo, I.S. (2011), "Outgassing characteristics of a polycarbonate core material for vacuum insulation panels", Vacuum, vol. 85, pp. 839-846. [31] Caps, R., Beyrichen, H. & Kraus, D. (2008), "Quality control of vacuum insulation panels: Methods of measuring gas pressure", Vacuum, vol. 82, no. pp. 691-699.

[32] Kreith, F., Manglik, R. M. & Bohn, M. S. (2011), Principles of heat transfer, 7th ed, Cengage Learning, Stamford. [33] The Charted Institute of Building Services Engineers (2006), CIBSE Guide A: Environmental design, London: CIBSE [34]Mackenzie, F., Pout, C., Shorrock, L. et al. (2010) Energy efficiency in new and existing buildings, BRE FB26, Bracknell, IHS BRE Press

[35] HM Government. (2010) Low-carbon construction IGT: final report. Department for Business, Innovation and Skills, Available from: HM Government. Web site: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/31773/1 0-1266-low-carbon-construction-IGT-final-report.pdf [Accessed: January 3, 2013].

45


APPENDICES Appendix 1: Insulation material chart from EST

46


Appendix 2-A: VIP products and prices of Va-Q-Tec Va-Q-Tec (http://www.va-q-tec.com/en/index_en.html)

Core material

Temperature

va-Q-vip

va-Q-vip B

va-Q-pur

va-Q-mic

va-Q-plus

va-Q-plus B silica

Silica board

Silica board

Polyurethane

micro fleece

(A)silica power

fumed Silica

fumed Silica

Polyurethane

open cell

inorganic oxides

inorganic oxides

foam

micro fleece

power

-70-+70

-70-+70

-70-+60

-70-+60

-70-+60

-70-+70

Initial thermal

<0.0043(at

<0.0043(at

0.007-0.009

0.0028-0.0035

< 0.0035

< 0.0035

conductivity(W/

20 mm

20 mm

mK)

thickness)

thickness)

Thickness (mm)

10- 50

10- 50

10-40

14-20

3-35

5-20

Service

up to 60

up to 60

up to 15

approx. 5

up to 60 years

up to 60 years

year(years)

years

years

years

years

Dimension(mm)

1000*600

1000*600

Max

1300*1000

400*250-1750*

1100*600*12/18

500*600

500*600

1200-1000

1000

500*600*12

Density

200

180-210

65

220

170-200

170-200

Application

Building

Building

Appliance

single-use

Packaging/Tran

Building application

application

application

Thermal

(internal and

thermal

thermal

sport

(internal and

packaging

external

transport pac

transport

Automotive

external insulation,

Appliance

insulation,

Automotive

for wall,

kaging

packaging(extr

Home appliance

for wall, floor, roof

emely little

Building

and facáde

insulation,

space is

application

insulation, etc)

etc)

available)

Technical

stability(°C)

floor, roof and facáde

device

47


Appendix 2-B: VIP products and prices of Va-Q-Tec

48


Appendix 3-A: Hourly heat gains/losses of the original house

Appendix 3-B: Hourly heat gains/losses of the EPS enhanced house

49


Appendix 3-C: Hourly heat gains/losses of the VIPs enhanced house

Appendix 3D: Hourly heat gains/losses on 29th January of original house, EPS enhanced house, and VIPs enhanced house (left-right)

50


Appendix 4: Solar cooling loads for fast-response building with single clear glazing: NW England: unshaded

51


52


Appendix 5: Solar heat gain on 29th January

53

Vacuum insulation panels in building application: a review, testing and modeling  
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