Chaykovskiy Geran T60KA Coparison of Theral Insulation Materials for Building Envelopes of Multi-storey Buildings in Sa-Petersburg Bachelor Thesis Deceber 010
Date of the Bachelor thesis 0.1.010 Author(s) Degree progra and option Chaykovskiy Geran Double degree progra Nae of the bachelor s thesis Coparison of Theral Insulation Materials for Building Envelopes of the Multi-storey Buildings in Sa-Petersburg Abstract This thesis is about coparing of different theral insulation aterials of different anufactures. In our days there are a lot of different theral insulation aterials which properties are very close to each other, but prices can be vary a lot. As a result, using of incorrect theral insulation aterial in building envelope can provoke lower cost efficient and low energy efficient of the project. ith a help of this work it is possible to choose ost energy-efficient and cost-efficient theral insulation aterial for building envelope with ventilated air cavity. Coparing of theral insulation aterial ade for outdoor walls of ulti-storey building in region of Sa-Petersburg ussia. But way of calculations in this thesis is ultipurpose and can be used also for another regions, and constructions of building envelopes. Subject headings (keywords) theral insulation, building envelope, theral resistance, heat transfer, anufacturing of theral insulation, ineral wool, foa plastic, expanded polystyrene, ruded polystyrene Pages Language UN 9, appendices 8 English earks, notes or appendices Tutor Martti Veuro Bachelor s thesis assigned by
CONTENTS APPENDICES... 4 LIST OF SYMBOLS USED... 4 1 INTODUCTION... 5 INVESTIGATION OF THE POPETIES OF THEMAL INSULATION MATEIALS... 6.1 Proble stateent... 6. Process of anufacturing of the ain theral insulation aterials... 7..1 The anufacture of the ineral wool... 8.. Process of anufacturing of the foa plastic... 10. equireents for the theral insulation aterials... 1..1 Main properties of theral insulation aterials... 1.. Deterining the values of the properties... 15.. Dependence between requireents and properties of the theral insulation aterials (foa plastic, and ineral wool)... 19.4 esults of the theoretical part... CALCULATION OF THE BUILDING ENVELOPE....1 List of the theral insulation aterials... 4. The coputational odel... 5..1 Operation conditions of the building envelope... 6.. Paraeters of the building envelope... 6. ay of the calculations... 7..1 Calculation of the theral resistance... 7.. Calculation of the teperature difference between the indoor air teperature and teperature of the ernal surface of the wall... 8.. Calculation of the teperature of the ernal surface of the building envelope... 9..4 Calculations of the air tightness of the building envelope... 0..5 Calculation of the possibility of condensation in building envelope... 1.4 esults of calculations... 5 4 CONCLUSION... 7 BIBLIOGAPHY... 8
APPENDICES Appendix 1. Calculation of the building envelope with the layer of theral insulation aterial 1 Appendix. Calculation of the building envelope with the layer of theral insulation aterial Appendix. Calculation of the building envelope with the layer of theral insulation aterial 7 Appendix 4. Calculation of the building envelope with the layer of theral insulation aterial 8 LIST OF SYMBOLS USED λ - theral conductivity [ / ( K) ] λ - theral conductivity at the teperature 7K [ / ( K) ] 0 0 i - theral resistance [ ] N γ - specific weight of air [ ] e - partial pressure E - axiu partial pressure α - coefficient of heat transfer [ ] 0 C des air tightness [ ] h Ω - resistance of the water vapor pereability [ [Pa] [Pa] h Pa ] 4
1 INTODUCTION In northern countries, builders have been forced to fight with low teperatures, cold winds, high huidity, and any other adverse weather conditions. For good work and cofortable life, huan need buildings with a good indoor cliate, which does not depend on weather conditions during the year. In our days it is ipossible to build walls fro brick or stone which thickness is close to one eter, because it will cost a lot of oney and nobody will pay for such heavy and expensive building. That s why the best way to save heat in wer tie, and not let in war in suer tie it is to use odern theral insulation aterials in building envelope. It will be very easy to build war walls, if we have such aterial, which is so strong as stone, so war as fluff, and so cheap as air. In odern structures, builders never use only one type of aterial in building envelope, because one aterial can prevent air leakage, other one protect fro weather conditions and another one can bearing loads. But only one layer, which consists of theral insulation aterial, can prevent heat transfer effectively. Theral insulation is the ain layer of building envelope, which can reduce heat losses and ake building ore energy efficient. So, the ain question is to choose correct theral insulation aterial which will help to satisfy requireents of building codes at the lowest cost. In y work I take ost coon design of building envelope and check, with which theral insulation aterial, properties of the building envelope becoes ostly close to requireents of building codes. As a result I have found the answer on a question: hich theral insulation aterial is ostly energy-efficient and cost-efficient. Soe anufactures of theral insulation aterials have ade coparison of their products, but in ost cases they ake a coparing using one or two paraeters. Also, usually anufactures coparing only their products, for exaple ineral wool, or polystyrene, but never a coplete building envelope with any layers. Builders are talking about coparing of different theral insulation aterials on special forus in the ernet, but usually, these disputes are ended without any results, because each person try to ake a coparing by their own way. As a result, nobody can answer, what cobination of what theral insulation aterials in building envelope are ostly energy-efficient and cost-efficient //. 5
INVESTIGATION OF THE POPETIES OF THEMAL INSULATION MATEIALS At first I will talk about object of investigation. And I will justify, that this object is real eresting to be investigated. N I will distinguish the ain groups of the theral insulation aterials which are will be investigated in y work. Then I will explain processes of anufacturing of the ain theral insulation aterials, to explain the reason of differences in properties of theral insulation aterials, which are anufactured fro the sae raw aterials. After that I will talk about ain requireents for theral insulation aterials, which are used in building envelope. ith a help of inforation fro previous paragraphs I will explain, how different properties of the theral insulation aterials help to achieve the requireents..1 Proble stateent Theral insulation aterial Other layers of building envelope Picture 1. Principle design of outdoor wall (with ventilated façade) of the building envelope of ulti-storey building /8/ 6
In Picture 1 it s possible to see that the layer of the building envelope, which consists of theral insulation aterial isn t so thick as other layers (about the I will talk in future paragraphs) but it s the ost iportant layer in a question of energy-efficiency and cost-efficiency. For exaple, price of theral insulation aterials can vary fro 50,4 euro/ to 105, euro/ (prices in Sa-Petersburg, Table ). And the V ti - volue of theral insulation aterial in a siple ulti-storey building can be calculated by the Forula.1.1. V = ( a + b ) h t (.1.1) ti where: a length of the building, a = 0 (for exaple); b length of the building, b = 50 (for exaple); h height of the building, h = 50 (for exaple); t thickness of the theral insulation, t = 0,1 (for exaple). V = (0 + 50 ) 50 0,1 = 700 ti And now, if we ultiply volue of the theral insulation aterial with different prices we will see, that price of the construction ay differ on 8500 euro depending on which theral insulation aterial will be selected for the building envelope. That s why in y work I want to find the ost energy-efficient and cost-efficient theral insulation aterial. The ain idea is to prove that so big price of the theral insulation aterials of soe anufactures is not a result of great technology, or best properties of the theral insulation aterials, just an advertiseent and P. At the sae tie I will prove that it s possible to build energy efficient building and archive the requireents of building codes with a help of low price theral insulation aterials. For this purpose I should look at all theral insulation aterials fro different perspectives. And I will start fro anufacture.. Process of anufacturing of the ain theral insulation aterials In this chapter I will talk about anufacturing of the ain theral insulation aterials like as: 1. foa plastic with open pore;. foa plastic with closed pore;. ineral wool fro slag; 4. ineral wool natural rock. Manufacturing process is eresting, because ain properties of those aterials are fored during anufacturing stage. Be failiar with it, is very useful for understanding how will 7
aterial work and what processes will take place in it, and also which aterial should be used in different situations...1 The anufacture of the ineral wool There are two ain types of ineral wool: 1. ineral wool fro slag;. ineral wool fro rock. This classification is based on the type of raw aterial. Most ineral wool produced today is produced fro slag or a ixture of slag and rock. Most of the slag used by the industry is generated by egrated iron and steel plants as a blast furnace byproduct fro cast iron production. Other sources of slag include the copper, lead, and phosphate industries.// Also, different countries always use slag as a raw aterial, but sources of this slag can be different. For exaple: 1. USA use slag which is stay fro blast furnace;. French, Sweden and Yugoslavia use slag which is stay fro blast furnace and add to it basalt or diabase;. Gerany use slag which is stay fro blast furnace, but add to it arl; 4. ussia use slag, which is a waste of iron industry. /5, p. 64./ But using the slag fro iron industry is a heritage of econoic policy of the USS. Because using of this slag give a positive effect for iron industry (because they can ake profit fro producing ineral wool fro this slag), but at the sae tie using of such slag have a harful influence on ineral wool. Because, it is very hard to keep properties of slag (fro iron industry) constant. As a result properties of ineral wool can be different. The following process description are based on the description given on the EPA website //. The production process has three priary coponents: olten ineral generation in the cupola, fiber foration and collection, and final product foration. The first step in the process involves elting the ineral feed. The raw aterial (slag and 8
rock) is loaded o a cupola in alternating layers with coke at weight ratios of about 5 to 6 parts ineral to 1 part coke. As the coke is ignited and burned, the ineral charge is heated to the olten state at a teperature of 100 to 1650 C (400 to 000 F). The olten ineral charge exits the botto of the cupola in a water-cooled trough and falls onto a fiberization device. Most of the ineral wool produced is ade by variations of fiberization ethods. The Powell process uses groups of rotors revolving at a high rate of speed to for the fibers. Molten aterial is distributed in a thin fil on the surfaces of the rotors and then is thrown off by centrifugal force. As the aterial is discharged fro the rotor, sall globules develop on the rotors and for long, fibrous tails as they travel horizontally. Air or stea ay be blown around the rotors to assist in fiberizing the aterial. A second fiberization ethod, the Downey process, uses a spinning concave rotor with air or stea attenuation. Molten aterial is distributed over the surface of the rotor, fro which it flows up and over the edge and is captured and directed by a highvelocity strea of air or stea. During the spinning process, not all globules that develop are converted o fiber. The nonfiberized globules that reain are referred to as "shot." In raw ineral wool, as uch as half of the ass of the product ay consist of shot. Shot is usually separated fro the wool by gravity iediately following fiberization. After foration and cheical treatent, the fiber is collected in a blowchaber. esinand/or oil-coated fibers are drawn down on a wire esh conveyor by fans located beneath the collector. The speed of the conveyor is set so that a wool blanket of desired thickness can be obtained. Mineral wool containing the binding agent is carried by conveyor to a curing oven, where the wool blanket is copressed to the appropriate density and the binder is baked. Hot air, at a teperature of 150 to 0 C (00 to 600 F), is forced through the blanket until the binder has set. 9
Curing tie and teperature depend on the type of binder used and the ass rate through the oven. A cooling section follows the oven, where blowers force air at abient teperatures through the wool blanket. To ake batts and industrial felt products, the cooled wool blanket is cut longitudinally and transversely to the desired size.// So, basing on inforation about anufacturing it is possible to ake soe findings: 1. The ain difference between properties of ineral wool is fire safety. If as raw aterials slag and rock, fire safety becoes higher up to 1000 0 C and if raw aterial is just a slag, fire safety is decrease to 600 0 C;. The price of ineral wool fro slag and rock is higher because it needs higher teperatures during the production (as a result ore energy), and ore expensive raw aterial as basalt, than ineral wool fro slag (Table );. The possible harful influence of the binder which is used to put together fibers. Because, usually as a binder use foraldehyde, which can have a harful influence on huan during the process of exploitation. But this harful effect is decrease close to zero with a help of hot air, at a teperature of 150 to 0 C (00 to 600 F), is forced through the blanket until the binder has set. Such heat treatent destroy all free particles of foraldehyde which can becoe free during the operation of the building, and ake a bad influence for huan.. Process of anufacturing of the foa plastic There are two ain types of foa plastic:. foa plastic with open pore (in following paragraphs expanded polystyrene) 4. foa plastic with closed pore (in following paragraphs ruded polystyrene) This classification is based on the way of anufacturing The raw aterial for this two types of aterials is the sae, they are therosetting polyer, aeration coponent, hardeners and different types of suppleents to correct properties of product. But there are two different technologies of processing of the raw aterial and as a result there are two different theral insulation aterials with different properties. 10
The following process description are based on the description given in a book theral insulation aterials and constructions /5/. The first one is expanded polystyrene. Method of anufacturing of this aterial at first was invented by Badisclie Anilin und Soda Fabrik A. Ci. BASF. The ain idea of this ethod is that at first, fro a single ass of polyer, anufacturing the prefabricated aterial which is called expandable polystyrene, it is consist of particles of ilk color, and have a for of little balls like beads. This particles contains aeration coponent, usually it is easy boiling liquid. Process of transforation of this particles to the final product consist of the heat treatent of particles which is invoke soften of polyer and derivation of little sticky, then starts widening of particles out of the evaporation of aeration coponent, and then gluing of the particles with each other. As a result we have aterial which is consist of a big nuber of separate particles, which structure is open. The second one is ruded polystyrene which is anufacturing by rusion ethod. This ethod was opened by Aerican copany Dow Cheical Copany, the ain idea is that polyer with a help of high teperature becoes in liquid fluid state and stay under the pressure. After this, aeration coponent added to it and this two coponents ixing with each other. On the n stage this ixture pushed through the ruder (soething like nozzles which have a for of future product). hile aterial coing through ruder pressure is decrease very fast and aeration coponent start to foa and in a structure of aterial little pore start to for. This pore has closed structure. The n stage of the anufacturing process is cooling of the product. And during this process aterial becoes hard /5/. The ain value of such anufacturing process is that subject of transforation is not separate pellets, but single ass of aeration coponent and polypropylene in fluid stage. And as a result, future aterial has closed pores and ore hoogeneous structure, than foa plastic with open pores. The quality of foa plastic is regulated by the nuber of residual onoer sterol, olecular weight and a content of aeration aterial: 1. Increasing of aount of onoer sterol decrease theral resistance, increase ability to aging and also increase harful influence on huan;. Molecular weight has big influence on strength and acoustic characteristics. So the increasing of olecular weight has good influence on strength and acoustic characteristics; 11
. Content of aeration aterial is connect with olecular weight. Because when anufacture try to get aterial with high olecular weight (to get better strength and acoustic properties) it should increase the nuber of aeration aterial, because the possibility to foa of the aterial with high olecular weight should be the sae as aterial with low olecular weight. At the sae tie big nuber of aeration aterial leads to a rapid evaporation of it fro the aterial. Soe of aterials which are used as aeration aterials (that which contain phenol) has a harful influence on huan Also properties of the foa plastics can be iproved by using different polyers as raw aterial: 1. Foa plastics based on polypropylene. Disadvantages of this kind of foa plastic is, low fire safety, instability of benzene and aterials which are based on solvents. But question of fire safety can be solved by adding flae retardants.. Foa plastics based on polyvinylchloride. Polyvinylchloride is theroplastic polyer which contain 56,8% of cobined chlorine, it is provide high fire safety properties.. Foa plastics based on polyurethane. Such foa plastics have very high flexibility, density (at the sae tie high theral resistance), So, basing on inforation about anufacturing it is possible to ake soe findings: 1. Extruded polystyrene is ore water resistant than foa plastic with open pore (which is produce by ethod of foa pellet). Because structure of closed pore prevented hit of water o the aterial and as a result prevent decreases of theral resistance.. Extruded polystyrene increase air tightness of the construction thanks to closed structure of pores;. Extruded polystyrene is ore huan safety. Monoer sterol and aeration coponent content in both types on foa plastics, but in ruded polystyrene, the possibility of evaporation of this coponent during the anufacturing process and the process of exploitation is decreased due to closed structure of the aterial. All free particles of onoer sterol, and aeration coponent are stay closed in pores; 4. Extruded polystyrene is ore strength then expanded polystyrene, because ruded polystyrene is ore hoogeneous, and the contact area between particles is higher, then in foa plastic with open pore. The reason is that ruded polystyrene anufactured fro a single liquid ass of polyer, and expanded polystyrene is anufactured fro separate pellets. 1
. equireents for the theral insulation aterials To find best solution for the construction of building envelope, it is iportant to choose theral insulation aterials which atch requireents. The ost iportant requireents are: 1. Low and constant, during all the period of exploitation, theral conductivity;. Possibility not to break down under different weather conditions and teperature of insulated object;. Not to cause the corrosion and breaking down of the insulated object; 4. Not to prevent teperature deforations of the insulated object (it eans to be flexible); 5. Life cycle of the theral insulation aterial shouldn t be lower then the life cycle of the insulated object; 6. Sound proofing should guarantee the allowable sound level for huan. To have an understanding of choosing the correct theral insulation aterial, which will atch to these requireents, it is iportant to know how to deterine ain properties of different theral insulation aterials...1 Main properties of theral insulation aterials Density. Knowing of the density of the aterial, gives a lot of inforation about it s theral insulation and strength characteristics. The lower is the density of the aterial, the lower is the theral conductivity. But as low density, as low possibility of installing of the aterial, and usually high water absorption, and as a result life of the aterial will be decrease. For deterining of the properties of the theral insulation aterial, uses average density. Porosity. As was said before, the lower density, the lower theral conductivity. Density depends on porosity. So, low density eans high porosity (it s ean a big aount of air in the aterial, which have very low theral conductivity 0,07 /( k ) at teperature 0 0 C /6, t. D1./) and low theral conductivity. Theral insulation properties don t depend only on porosity, but also on kind of the aterial, structure of pore, there size and for, unifor of the distribution of pores in the aterial and also are pores closed or open, can they counicate with surroundings air. So, the best theral insulation properties have aterials with a big aount of little closed pores which are have unifor distribution in the volue of the aterial. 1
Theral conductivity it is a property of the aterial to transfer the heat flow, which is coe fro teperature difference between opposite surfaces. Different aterials provide the heat flow with different speed (iron do it faster, and theral insulation aterial do it slower). Theral conductivity depends on average density of the aterial (if average density increase, theral conductivity starts to decrease), it s structure, porosity, huidity (if of the aterial start to increase, theral conductivity start to decrease very fast) and teperature of the aterial of the layer. That s why all theral insulation aterials should be storaged in dry conditions. Dependence between theral conductivity - λ, and average teperature of the aterial layer can be express by forula 4.1.1. λ = λ + b t (4.1.1) 0 average where: λ - theral conductivity, / ( K) ; λ - theral conductivity at the teperature 7 K, / ( K) ; 0 b - constant value for each aterial, which shows the change of theral conductivity during the change of teperature on 1K; t average - average teperature of the aterial, K. Fro forula 4.1.1 we can see, that while the average teperature of the aterial and b increase, theral conductivity of the aterial is increases too. So, aterials with high density, have higher b. Heat capacity it is a property of the aterial to absorb heat Huidity. Theral insulation aterials can t be always dry, because they absorb the oisture fro surroundings air (sorption huidity), or during the contact with it (with a help of water absorption). During the huidification of theral insulation aterials, there theral conductivity rises very fast. Because when theral insulation aterial is dry it s pores and free area in the structure are field by the air with a low theral conductivity (0,07 /( k teperature 0 0 C), and after huidification this pores and free areas start to be filled by water which theral conductivity is rather high (0,6 /( k ) at teperature 0 0 C /6, t. D1./). ) at ater vapor pereability it is a property of the aterials to skip water vapor, which air contains, because of differences of partial pressures on opposite surfaces of the aterial. Partial pressure is a part of full pressure of ixture of gases, fro which air consists. Partial pressure of 14
water vapor is equal to the pressure of water vapor if it will occupy all volue of air at the teperature of air. Partial pressure of water vapor increases while teperature is increases. So, water vapor is seeking to the area of lower pressure, in another words, on a side of aterial with lower pressure. That s why it s very iportant to prevent the contact of theral insulation aterial with oistening surfaces or water vapor. Sound absorption and sound proofing are two very iportant characteristics for theral insulation aterials, which are used in a building envelope (ost of all for such case, which is considered in this work, building envelope for ulti-storey building) Sound is a ixture of different noises which are erfere to perceive helpful and needed sound inforation, or it can give a harful influence on a huan. Sound absorption is a degree of sound ake of the aterial. Sound proofing is a weakening of sound energy which is coing through the building envelope. The greater the porosity then the greater sound absorption properties of the aterial. Materials with open and counicated with each other pores are better for sound absorption, than aterials with low porosity, and closed pores. Sound absorption aterials include aterials with hard fiber structure (for exaple hard ineral wool) or cellular structure (for exaple cellular concrete). Sound proofing aterials (for exaple soft ineral wool). Sound absorption aterials are used for insulation fro different noises (noise fro cars, streets). Sound proofing aterials are used for insulation fro different vibrations which are coing through building structure (vibrations fro tras, trains, heavy cars, shock vibrations in different flats or other buildings). That s why sound proofing aterials are don t used in such part of building envelope as outdoor walls. Because the ain goal of outdoor walls to insulate huan fro different noises... Deterining the values of the properties Density value equal to the ratio of ass of substance to it s volue (pores and voids don t take o account). 15
Units of density are: g/c, /, tn/. Density is calculating using the forula 4..1: where: ρ - is a density of substance, (/ ); is a ass of substance, (); V is a volue of substance, ( ) ρ = / V (4..1) Average density value equal to the ratio of the ass of substance to whole volue of the substance (including pores and voids). Units of density are: g/c, /, tn/. Average density is calculating by forula 4..: where: is a ass huidity of the aterial, (%) ρ = /[ V (1 + 0,01 )] (4..) To calculate an average density we need to know, V,. Mass can be find by weighing. Huidity can be find by drying of the aterial with teperature 105 ± 5 0 C. But deterining of the volue of the aterial is not very easy, because ineral wool can change it s volue according to the surroundings conditions. That s why for deterining of the volue of ineral wool using special easuring unit Picture. Principle of working: follower plate press on the aterial which is put in cylinder 1 with strength 0,00 MPa /5, p.9./, and after 5 inutes, using the scale of the rod we easuring h and using Forula 4.. we can calculate volue V. V π h where: is radius of the cylinder 1, () = (4..) 16
Picture. Measuring unit for deterining of the average density of loose, fiber aterials /5, p. 40./ 1 - cylinder; - follower plate; rod with a scale; 4 lifting echanis Porosity - is the degree of filling of the aterial by pores. Total porosity P t, (%) is a ratio between the volue of pores V por, to whole volue of the aterial V. For the calculation of the total porosity, using Forula 4..4. Vpor Pt = ( ) 100 (4..4) V In another way we can calculate total porosity by forula 4..5. P t ρv = (1 ) 100 (4..5) ρ where: ρ v - bulk density of the product, g/c ; Theral conductivity. Theral conductivity characterized by the aount of heat (J), which is coes through the layer of the aterial which thickness is 1 eter and surface area 1, during 1 hour. Material can be using as theral insulation aterial if it s theral conductivity is less than 0,175 / ( K) at teperature 98 K and noral huidity. 17
Theral conductivity can be calculated by the Forula 4..6. q δ λ = (4..6) t t 1 where: q heat flow, which is coing through the aterial with area 1, / ; δ - thin of the saple of the aterial, ; t 1,t teperature of the upper and lower surfaces of the saple, K. Heat flow can t be calculated by any forulas, it can be just easuring by special easuring unit, as on Picture. Principle of working is that between two therostatically plates 1 and, with a help of which create and support needed teperature differences, putting a saple of the aterial (size is 50*50., thickness is 10-50.) Between the lower plate 1 and the saple, putting calorieter 6 (which is easuring the heat flow). Teperature on the surfaces of the saple, changing by two therocouples 4. Heat flow creating fro up to down. Picture. Measuring unit for deterining of the heat flow /6, p.4./ 1, therostatically plates; saple of the aterial; 4 therocouple; 5 theral insulating cover; 6 calorieter. Heat capacity deterining as an ratio between aount of heat, which is given to the aterial, and an appropriate changing of the teperature. So heat capacity can be calculated using Forula 4..7 Q C = (4..7) T where: C heat capacity of the aterial, J/K; Q aount of heat which is given to aterial, J; T changing of teperature during the heating of it, K. Huidity - content of the oisture in the aterial, it can be calculated by the Forula 4..8 18
( i ) = [ ] 100 (4..8) where: ass of the aterial in natural conditions, g; i ass of the aterial, which is drying to a constant ass; huidity, %. i Sorption huidity sorp is depends on huidity and teperature of the abient air, and also of structure of the aterial. Sorption huidity can be calculated by the Forula 4..9 sorp = 1 [ ] 100 (4..9) where: 1 ass of the container with the saple of the aterial after keeping above the water, g; ass of the container with dry saple of the aterial, which is drying up to constant teperature, g; ass of the dry container, g. ater absorption of theral insulation aterials is characterize by the aount of water, which can be absorb by the aterial, divided by ass of the dry aterial. ater absorption can be calculated by the Forula 4..10 where: 1 ass of the aterial in dry conditions, g; ass of the aterial in full of water conditions, g. 1 abs = [ ] 100 (4..10) 1 ater vapor pereability is characterized by the coefficient of water vapor pereability, which is deterining by the aount of water vapor (g), which is going through the layer of the aterial, which area is 1, during 1 hour, at the pressure difference on opposite surfaces is 1, Pa (one illieter of ercury) /5, p.9./... Dependence between requireents and properties of the theral insulation aterials (foa plastic, and ineral wool) In previous paragraph I write the ain requireents which are offered for theral insulation aterials which are used in building envelope. These requireents are: 1. Low and constant, during the all period of exploitation, theral conductivity; 19
. Possibility not to break down under different weather conditions and teperature of insulated object;. Not to cause the corrosion and breaking down of the insulated object; 4. Not to prevent teperature deforations of the insulated object (it s ean be flexible); 5. Life cycle of the theral insulation aterial shouldn t be lower then the life cycle of the insulated object; 6. Sound proofing should guarantee the allowable sound level for huan. Also, in previous paragraphs I identified ain groups of the theral insulation aterials, based on the technology of anufacturing. This groups are: 1. expanded polystyrene;. ruded polystyrene;. ineral wool fro slag; 4. ineral wool fro rock. Now with a help of knowledge about technology of anufacturing theral insulation aterials, and their properties, it will be useful, to ake a conclusion about dependence between requireents and properties of the theral insulation aterials. It will help to copare the constructions of the building envelopes in following paragraphs. Influence of the ain properties on the ain requireents, for the ain groups of the theral insulation aterials are shown in the Table 1. Table show an influence of properties of the theral insulation aterials (Density, porosity, theral conductivity, huidity, water vapor pereability, sound absorption and sound proofing) on each of the ain requireents. 0
Table 1, Influence of the ain properties on the ain requireents, for the ain groups of the theral insulation aterials Nae of the group of the theral insulation aterial Expanded polystyrene Extruded polystyrene Low and constant theral conductivity Can be decreased due to absorbing the water due to open structure of the pore, and a lot of free space in structure Can save it s theral conductivity on a constant level during the life cycle of the insulated object, due to closed structure of pore and absent of free space inside the aterial. esistance to different weather conditions Should be protect fro water, due to open structure of pore. Also fro high teperatures (higher than +75 0 C) due to raw aterial, which can t withstand high teperatures. Material can t be used as air barrier. Have a high level of the resistance to weather conditions due to closed pores and absent of free space in inside. Also can be used as air barrier, due to possibility of sealing between the lists of the aterial. But, also should be protect fro teperatures higher than +75 0 C Properties of the theral insulation aterials Prevent corrosion and breaking down of the insulated object Should be insulated fro different kinds of iron structures, because, aterial can provide water and cause the corrosion of the steel structures. Can protect insulated structure fro corrosion, because, this aterial don t absorb water. Also can protect different kinds of insulated structures fro outdoor ipacts. Flexibility Long life cycle Sound proofing Has a low opportunities to flexibility, due to during the anufacturing process, object of the heat treatent are separate particles of polystyrene. So, the contact between particles of polystyrene isn t very strong Has a high opportunities to flexibility, due to during the anufacturing process, object of heat treatent is a single ass of polystyrene. So, the contact between particles of structure is very strong, and can withstand deforations. Live cycle can be decreased due to contact with water, deforation of the construction, or contact with different substances which are based on solvents Live cycle can be decreased due to contact with different substances which are based on solvents Can t be used as sound proofing, but it s sound proofing properties are better than ruded polystyrene. Because pore are open, and they are big (0,-0,4 ). But structure of the aterial is too hard to absorb the energy of sound wave Can t be used as sound proofing, because pore are closed, and they are too sall (0,1-0, ). And the structure of the aterial is too hard to absorb the energy of sound wave 1
Mineral wool fro slag Mineral wool fro rock Can be decreased due to absorbing the water due to spongy structure. Because during the anufacturing process any fibers are glue with each other and for structure with a lot of big and counicated with each other pore, with a lot of free space with each other. Can be decreased due to absorbing the water due to spongy structure. Because during the anufacturing process any fibers are glue with each other and for structure with a lot of big and counicated with each other pore, with a lot of free space with each other. Can t prevent harful influence of weather conditions, so it should be protect fro wind, snow and water by other protecting aterials. Application teperature is up to +400 0 C. Can t prevent harful influence of weather conditions, so it should be protect fro wind, snow and water by other protecting aterials. Application teperature is up to +800 0 C. Can t prevent the corrosion of iron structure, due to absorbing the water. So it should be separate fro iron structures. Also this aterial can have a harful influence for other surrounding aterials. Because it can keep absorbing water for a long tie, and har other constructions. Can t prevent the corrosion of iron structure, due to absorbing the water. So it should be separate fro iron structures. Also this aterial can have a harful influence for other surrounding aterials. Because it can keep absorbing water for a long tie, and har other constructions. Has a high opportunity to flexibility, because it consist of fibers, which a flexible. But Flexibility increases while density increases. Has a low opportunity to flexibility, because it consist of fibers, which a not flexible (raw aterial is rocks). Also density of such aterials are usually high (>100 / ), which is not good for flexibility. Life cycle can be decreased due to absorbing water. Also if ineral wool with low density (<100 / ) will put o walls, it will clod. Life cycle can be decreased due to absorbing water. But this kind of aterial isn t clod, because fibers are thicker, and density is high enough (>100 / ) Mineral wool with low density (<100 / ) is very good aterial for sound proofing, because it has structure, which is consist of fibers, which connections with each other is soft. So, when sound wave contact with it, it can absorb energy of the wave. Also, a lot of big (1-5 ) pore, counicated with each other, give a good effect. It s good to insulate fro ipact noise, and vibrations. Such ineral wool with high density (>100 / ) is very good aterial for sound absorption, because it has structure, which consist of fibers, which connections with each other is harder than in ineral wool fro slag. So this aterial is better to use for insulation fro noise.
.4 esults of the theoretical part As a result of theoretical part I identified the ain group of the theral insulation aterials which are ostly coon during the construction of the building envelope of the ulti-storey buildings in our days. These groups are: 1. expanded polystyrene;. ruded polystyrene;. ineral wool fro slag; 4. ineral wool fro rock. I have explained the eanings of the ain properties of the theral insulation aterials for reader. And I have been explain the processes of deterining the values of properties, because, reader should understand the eaning of the properties before he start to read practical part of the thesis. And, based on the whole inforation fro theoretical part I have fored Table 1, to explain the dependence between properties of the ain groups of the theral insulation aterials and the ain requireents. Table 1 help to understand, which properties of any theral insulation aterials helps it to achieve the requireents. CALCULATION OF THE BUILDING ENVELOPE In this part of the work I will talk about coparing of one, ostly coon in Sa-Petersburg, design of building envelope, but with different theral insulation aterials (fro ain groups of theral insulation aterials which were identified in previous chapter). I will ake calculations of building envelope based on ussian building codes. The ain requireents, which are offered to building envelope are /7/: 1. Theral resistance;. Teperature difference between indoor air teperature and teperature of the surface teperature;. Air tightness of the wall; 4. ater vapor pereability. As I said before, in y work I looking for not all parts of building envelope, such as (roof, walls of underground floors, floors, etc.), but only for outdoor walls of ulti-storey buildings.
.1 List of the theral insulation aterials In Table there is a list of the theral insulation aterials, of different ostly coon on a arket of Sa-Petersburg anufactures, which will be coparing with each other. Table List of the properties of the theral insulation aterials 1 4 5 6 7 8 Nae of the aterial Mineral wool fro slag Fasad tero plita 0 Mineral wool fro rock aroc AS5 Mineral wool fro rock Venti bats Mineral wool fro rock FE75 Mineral wool fro rock Technovent optia Extruded polystyrene - 0-50 Extruded polystyrene Penoplex - 1 Expanded polystyrene Knauf Ther Facade Nae of the anufacture KNAUFINSUL ATION PAOC OCKOOL KNAUFINSUL ATION TechnoNICOL TechnoNICOL PENOPLEX KNAUF- PENOPLAST Theral conductivity λ, K 0,040 /1/ 0,04 /14/ 0,045 /16/ 0,048 /19/ 0,047 // 0,01 /5/ 0,0 /7/ 0,06 /9/ Specific heat capacity c, kj K 0,7 /1/ 0,78 /15/ 0,8 /18/ 0,81 /1/ 0,79 /4/ 1,45 /5/ 1,45 /7/ 0,98 /0/ Density ρ, 50 /1/ 85 /15/ 90 /16/ 85 /1/ 81-99 // 5-0 /5/ 0,5 /7/ 0 /0/ ater vapor pereability g µ, h Pa 0,5 /1/ 0,45 /15/ 0, /16/ 0,5 /19/ 0, // 0,011 /5/ 0,008 /7/ 0,05 /0/ Price of the 1 euro 50,6 /1/ 115 /15/ 8,4 /17/ 105, /0/ 8,4 // 87,6 /6/ 79,6 /8/ 50,4 /9/ All prices were calculated according to 4,7 rub. by 1 euro at 1.10.010 4
. The coputational odel As the estiated construction of outdoor wall I have been taken ostly coon for Sa- Petersburg type of it s construction, Picture : 4 1 5 6 7 8 9 Picture. Principle design of outdoor wall (with ventilated façade) of the building envelope of ulti-storey building /8/ 1 aerated concrete; plugs; ceent-sand plaster; 4 theral insulation; 5 guides; 6 fixing eleents; 7 facing aterial; 8 air cavity; 9 air barrier 5
..1 Operation conditions of the building envelope. Outside conditions: Study area Sa-Petersburg; Air teperature - -6 0 C (it s a teperature of the coldest five days with probability 9%) /9, t.1*/; Air huidity ϕ = 86% (it s an average level of air huidity during the coldest onth) /9, t.1*/. Inside conditions: Air teperature - + 0 C (it s a teperature for residential buildings) /6, t.1/; Air huidity ϕ = 55% (it s an air huidity for residential buildings) /6, t.1/; Huidity indoor ode noral /7, t.1/; Operation conditions of the building envelope noral /7, t./... Paraeters of the building envelope In Table there are all theral insulation aterials which are used in taken o account building envelope. Air cavity nuber 8, and facing aterial don t have any influence on a theral resistance of the building envelope, because air cavity is ventilated /10, p.19/, so I can ake a decision that the last layer of building envelope, which should be taken o account it is Air barrier. But I will coe back to the role of ventilated air cavity and facing aterial in future paragraphs. Table Properties of the aterials of the building envelope Nae of the aterial Thickness Theral Specific heat ater vapor of the conductivity capacity Density pereability layer kj λ, c, ρ, g δ, K K µ, h Pa 1 Ceent-sand plaster 0,01 0,9 0,84 1800 0,09 Blocks of aerated concrete 0,15 0,15 0,84 400 0, Theral insulation aterial 4 Air barrier TYVEK 0,001 0,7 1,08 600 0,01 6
Also, in the construction we have soe iron eleents, such us fixing eleents, and guides. They will be calculated as theral bridges, λ = 6. K Inforation in rows 1, and 4 in Table will be constant for our calculations, but inforation in row will be taken fro Table. In such a way I will ake calculations for each type of theral insulation aterial fro 1 to 9, fro Table.. ay of the calculations..1 Calculation of the theral resistance All forulas which were using in calculations are taken fro ussian building codes /6/, /7/, /9/.Calculations are starting fro calculating of degree days of heating season. D d is calculating using the Forula..1.1: D = ( t t ) z (..1.1) d ht ht where: t the ernal teperature, t = + 0 C; t ht the average teperature during the heating season, t ht = -1,8 0 C; z ht the tie length of heating season (nuber of days with average teperature less than +8 0 C) z ht = 0 /9, t.1*/ Theral resistance 0 should be the sae or higher than req, which value is calculating depending on D d, by using the Forula..1.: where: a coefficient which is choosing by /7, t.4/, a=0,0005; D d degree days of heating season; b coefficient which is choosing by /7, t.4/, b=1,4. = a D + b (..1.) req d Now, I know the norative level of theral resistance req, according to SNIP -0-00. Theral protection of the building i - Theral resistance of the aterial layer is calculating, using the Forula..1.: where: δ i, λ I this values are taken fro Table δ i i = (..1.) λi 7
Theral resistance of the layers, which consist of different aterials which have different values of theral conductivity - λ i, λ j are calculating by the Forula..1.4: i, j = i ( Aj 100) j (..1.4) where: A j square of the aterial (etal plates) on 1 square eter of the building envelope. After this I should calculate T - total theral resistance of the building envelope using Forula..1.5: T = si + 1 + +... + n + se (..1.5) where: si + se the su of the ernal and ernal surface resistance, si + se =0,16 0 0 1,, n - theral resistance of the inhoogeneous aterial layer 1,,... n, Now it s necessary to satisfy the condition, that T req If this condition is satisfied, it s ean that theral resistance level of the building envelop is satisfy, according to SNIP -0-00. Theral protection of the building.. Calculation of the teperature difference between the indoor air teperature and teperature of the ernal surface of the wall Design value of the t0 - teperature difference between the indoor air teperature and teperature of the ernal surface of the wall shouldn t be higher than the norative value, t n = 4 0 C /7, t.5/. It s iportant to satisfy this rule to create cofortable conditions for future occupants of the building. t0 can be calculated using the Forula...1: n ( ti nt t ) t0 = α T (...1) where: n coefficient which is depending on orientation of the building envelope to outdoor air n=1 /7, t.6/ α - coefficient of heat transfer of the ernal surface of the building envelope C α =8,7 0 /7, t.7/ Now it s necessary to satisfy the condition, that t0 tn 8
If this condition is satisfied, it s ean that teperature difference between the indoor air teperature and teperature of the ernal surface of the wall is satisfy, according to SNIP - 0-00. Theral protection of the building... Calculation of the teperature of the ernal surface of the building envelope The n one iportant step it is the calculation of the t si teperature of the ernal surface of the building envelope. This teperature should be higher than t dp dew po teperature, to prevent the condensation of the water vapor on the ernal surface of the building envelope. t si can be calculated by the Forula...1: t = t t (...1) si 0 After the calculation of the t si it is possible to find t dp, by using the Mollier chart, Picture 4. Picture 4. The Mollier psychroetric chart. Now it s necessary to satisfy the condition, that t si t dp If this condition is satisfied, it s ean, that the condition of preventing the condensation of the water vapor on the ernal surface of the building envelope is satisfied according to SNIP -0-00. Theral protection of the building. 9
..4 Calculations of the air tightness of the building envelope To calculate the air tightness of the building envelope, it s iportant to know air tightness properties of each aterial of the building envelope, Table 4. And after this table, values of the air tightness should be suarized. Properties of the theral insulation aterials will be change. Table 4. Air tightness properties of the aterials of the building envelope /6, t.17/ Nae of the aterial Thickness Density Air tightness des, of the h Pa layer ρ δ,, 1 Ceent-sand plaster 0,01 1800 7 Blocks of aerated 0,15 400 1 concrete Theral insulation aterial 4 Air barrier TYVEK 0,001 600 10 Σ 404 At first should be calculated the specific weight of the erior and erior air can be calculated by the Forula..4.1: γ γ 46 = 7 + 46 = 7+ t t (..4.1) Moving of the air through the building envelope is due to pressure differences on the opposite surfaces of the building envelope. The pressure difference on the erior and erior surfaces of the building envelope - where: H height of the building, H = 50 ; p can be calculated by the Forula..4.: p = 0,55 H ( γ γ ) + 0,0 γ V (..4.) N ; γ, γ - specific weight of the erior and erior air, V axiu of the average values of the wind speed, during the January, V = 5,5 r /6, t.1/ Air tightness of the building envelope of the residential buildings des, shouldn t be lower than the norative value req, which can be calculated by Forula..4.1: 0
where: req p = (..4.1) G n p - the pressure difference between erior and erior surfaces of the building envelope; G n norative value of the air tightness of the building envelope, G n =0,5 /7, t.11/. h Now it s necessary to satisfy the condition, that des req If this condition is satisfied, it s ean, that the condition of the air tightness of the building envelope is satisfied according to SNIP -0-00. Theral protection of the building...5 Calculation of the possibility of condensation in building envelope hen air is coing through the building envelope (in wer tie) it s teperature decreases and it can reach the dew po teperature and provoke the condensation. Condensation of the water vapor is very harful for the theral insulation aterial, about it I have been wrote in previous paragraphs. At first it is iportant to calculate the partial pressure of the saturation water vapor on the ernal and ernal surfaces of the building envelope by the Forula..5.1: e e ϕ E 100 ϕ = E 100 = (..5.1) where: e, e - partial pressure of the water vapor on the ernal and ernal surfaces of the building envelop; E E - axiu partial pressure of the water vapor on the ernal and ernal, surfaces of the building envelope. The value of the axiu partial pressure can be deterined by the diagra which is show the dependence between E and t, E=f(t) Picture 5. Such diagra can be drawn using the values fro Table 5. 1
Table 5. Dependence between axiu value of the partial pressure of the water vapor and teperature of the air t, o C E, Pа t, o C E, Pа t, o C E, Pа t, o C E, Pа -40,0 1,40-10,0 60,0 8,0 107 0,0 8-5,0,6-5,0 401, 10,0 18,0 644-0,0 7, 0,0 610,6 1,0 140 4,0 984-5,0 6,66,0 705, 14,0 1599 6,0 61-0,0 10,7 4,0 81, 16,0 1817 8,0 780-15,0 165, 6,0 94,6 18,0 064 0,0 44 Picture 5. Dependence between partial pressure of the water vapor and teperature. The ain idea is to deterine the Maxiu values of the partial pressure of the water vapor and the real values of partial pressure of the water vapor (with a help of teperature in the plane of possible condensation in the building envelope, and Picture 5), and after this draw it on a one diagra, and find spaces where real values of the partial pressure becoes higher than axiu value. In this zone the condensation of the water vapor becoes possible/11, p. 18/ The teperature in the plane of possible condensation in the building envelope -τ i can be calculated by the Forula..5.. e should nubered layers of the aterial fro inside to outside. τ ( t t ) ( + ) i si i i = t (..5.) T