The requirements for private houses and apartments in terms of heat retention have increased significantly. Many resort to additional finishing of attic floors, external walls due to the constant increase in the cost of energy.
In recent years, enough materials have appeared that can significantly improve heat conservation in a private house or apartment. They also have a number of other properties, which in general make them an excellent alternative to major renovations.
Varieties and description
Materials with different mechanical properties are offered to consumers' choice.
Ease of installation and properties largely depend on this. According to this indicator, there are:
- Foam blocks... They are made of concrete with special additives. As a result of a chemical reaction, the structure is porous.
- Plates. Building materials of various thicknesses and densities are made by pressing or gluing.
- Cotton wool. It is sold in rolls and has a fibrous structure.
- Granules (crumb). with foam substances of various fractions.
It is important to know: selection of material is carried out taking into account properties, cost and purpose. The use of the same insulation for the walls and the attic floor will not provide the desired effect, unless it is indicated that it is intended for a specific surface.
Various substances can be used as raw materials for insulation. They all fall into two categories:
- organic based on peat, reeds, wood;
- inorganic - made of foamed concrete, minerals, asbestos-containing substances, etc.
Basic properties
The effectiveness of a material largely depends on three main characteristics. Namely:
- Thermal conductivity... This is the main indicator of the material, expressed by a coefficient, calculated in watts per 1 square meter. Depending on the level of heat retention, a different amount of insulation is required. It is significantly influenced by the moisture absorption rate.
- Density. An equally important characteristic. The higher the density of the porous material, the more efficiently heat will be retained inside the building. In most cases, it is this indicator that is decisive when choosing a heater for walls, floor slabs or roofs.
- Hygroscopicity. Resistance to moisture is very important. For example, basement floors, which are located in damp places, it is important to insulate with a material with the lowest hygroscopicity, such as, for example, plastic form.
It is necessary to pay attention to a number of other indicators. This is resistance to mechanical damage, temperature extremes, flammability and durability.
Comparison of key indicators
To understand how effective one or another insulation will be, it is necessary to compare the main indicators of materials. This can be done by reviewing Table 1.
| Material | Density kg / m3 | Thermal conductivity | Hygroscopicity | Minimum layer, cm |
| Expanded polystyrene | 30-40 | Very low | Average | 10 |
| Plastiform | 50-60 | Low | Very low | 2 |
| 60-70 | Low | Average | 5 | |
| Styrofoam | 35-50 | Very low | Average | 10 |
| 25-32 | low | low | 20 | |
| 35-125 | Low | High | 10-15 | |
| 130 | Low | high | 15 | |
| 500 | High | Low | 20 | |
| Aerated concrete | 400-800 | High | High | 20-40 |
| Foam glass | 100-600 | Low | low | 10-15 |
Table 1 Comparison of the thermal insulation properties of materials
At the same time, many people prefer plastic form, mineral wool or aerated concrete. This is due to individual preferences, installation features and some physical properties.
Application features
Before deciding on the materials for finishing a private house or apartment, it is necessary to correctly calculate the thickness of the layer of a particular insulation.
- For horizontal surfaces (floor, ceiling) almost any material can be used. The use of an additional layer with high mechanical strength is mandatory.
- It is recommended to insulate basement floors with building materials with low hygroscopicity. Increased humidity must be taken into account. Otherwise, the insulation will partially or completely lose its properties under the influence of moisture.
- For vertical surfaces (walls) it is necessary to use plate-and-sheet materials. Bulk or rolled will sag over time, so you need to carefully consider the method of fastening.
Installation of various types
When choosing this or that material for better preservation of heat in a house or apartment, you need to take into account the features of its installation. The complexity and set of tools for installation work largely depends on the form of thermal insulation. Namely:
- expanded clay. It is used exclusively for floors and intermediate floors. You need an entrenching tool and additional building materials (screed or boards). You will also need a waterproofing layer in the form of roofing felt or other similar material.
- mineral wool... Correct installation involves the use of a hand tool to secure the frame. Mineral wool is very easy to install in pre-prepared cells, but uniform fastening is required over the entire plane. A waterproofing layer on top of the insulation is a prerequisite for long-term operation. It can be used for vertical and horizontal surfaces.
Note: when installing any type of insulation, it is important to remember about hydro and vapor barrier. Protecting the finish from direct moisture is very important.
- styrofoam. Plates are attached to the surface with dowels with "dimes". Among the necessary tools are a screwdriver, a hammer drill, a construction knife and dowels. The shape of the building material and light weight allows you to even independently perform the entire volume of work in a short period of time.
- foam glass... For a tight connection to the surface, mechanical fasteners or mortars (cement, mastics and other adhesives) are used. The choice depends on the material of the walls. Blocks are very popular, but there are also slabs and granules in the range.
What to choose
New building materials appear at various exhibitions every year. With their help, you can significantly reduce energy costs in the cold season. But which of them will be the best solution in all respects. Experts differ in many ways.
The selection of material is based on properties, cost and ease of installation. Manufacturers apply certain markings to products, which greatly simplifies the selection. For example, foam for walls, floors or roofs has different properties and special marks.
Many people prefer mineral wool in dry rooms, foam in rooms with high humidity, and sprayed insulation for hard-to-reach places.
Which insulation is better: ecowool, stone wool or expanded polystyrene, see the following video:
We do not live in the hottest country on Earth, which means that we have to heat our homes for at least most of the year. This explains such a high demand for.
Of all the materials used for insulation of residential and other objects, polyurethane foam, expanded polystyrene and mineral wool are now especially popular. Let's talk about the last two of them.
Mineral wool
Mineral wool is a material based on basalt fiber.
Mineral wool may not be used everywhere, since it has a lower temperature limit. For example, this one cannot be used in a refrigerator.
Under the influence of low temperatures, mineral wool becomes brittle and deformed, which is unacceptable for insulation. Here, as a comparison of heaters in terms of thermal conductivity shows, the advantage is on the side of expanded polystyrene, which has no lower temperature limit.
As for the upper temperature limit, it all depends on the mechanical stress during exposure to high temperatures and the duration of this exposure. If you are interested in the thermal conductivity of heaters, the table that is on our website will help in obtaining information about this. In particular, there is given the thermal conductivity coefficient of mineral wool.
Mineral wool allows steam and moisture to pass through. This significantly reduces its thermal insulation properties. Also, the accumulation of moisture contributes to the development of mold and mildew, rodents begin to settle in the insulation, putrefactive bacteria, etc.
Also, mineral wool insulation is hygroscopic, which is why it is necessary to erect ventilated walls and a roof. In some cases, this leads to a large expenditure of funds.
Mineral wool insulation is 1.5-3 times heavier than its counterpart. Hence the higher cost of transporting it. Also, the disadvantage is that such insulation can be used only when the foundation of the structure, which is insulated with it, is strong enough. Of course, it is more difficult to carry out loading and unloading and construction and installation work using a large amount of insulation.
Expanded polystyrene
Compared with the above-described insulation, expanded polystyrene insulation has better characteristics. The thermal insulation properties of this material are high, as a result of which, its use becomes economically viable.
Insulation from expanded polystyrene, in addition to good thermal insulation properties, absorbs noise well, resists bacteria and fungi. Also, this material is resistant to the effects of solutions of alcohols, acids and alkalis. The coefficient of thermal conductivity of expanded polystyrene and its other characteristics can be found out by examining the "thermal conductivity of heaters table" on our resource.
One of the main advantages of expanded polystyrene is its ability to withstand a sufficiently large mechanical load at a minimum density value.
It is necessary to highlight the advantage of expanded polystyrene over mineral wool. Since it has a low average density, it practically does not change the load on the foundation and supporting structures.
Comparison of heaters in terms of thermal conductivity shows that, depending on the density, the thermal conductivity coefficient of mineral wool is 0.048-0.07; - 0.038-0.05.
Other properties of the described heaters
Mineral wool insulation is non-flammable. The fire resistance of these materials is determined not only by the properties of the material, but also by the conditions in which they are used.
The degree of fire resistance is greatly influenced by what materials the insulation is combined with. The way of arrangement of protective and covering layers also plays a role.
As for expanded polystyrene, it belongs to self-extinguishing materials. Therefore, the walls decorated with it do not ignite so quickly. And if this does happen, the flame spreads over their surface also slower than in the case of other heaters.
When a polystyrene foam insulation burns, about 1000 MJ / m3 heat is released, which is 7-8 times less than when burning a dry tree. The self-combustion time of expanded polystyrene is no more than a second.
Mineral wool is a non-flammable substance. Therefore, the flammability of the surfaces lined with it, as well as the spread of the flame along them, is minimal. Since the basis of this insulation - basalt - is a natural stone, mineral wool is able to withstand temperatures - up to 1000 ° C, and can resist the spread of fire - up to three hours.
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Penoplex or mineral wool
Penoplex is a polystyrene derivative, a product of organic chemistry. Mineral or basalt wool is a product of thermal processing of mineral raw materials. Both materials are successfully used in the creation of heat-insulating layers, but there are features of the use of each of them, this is explained by some physical indicators.
Physical indicators of mineral wool:
- density - varies widely and can be from 10 to 300 kg / m3;
- thermal conductivity (at a density of about 35 kg / m3) - 0.040-0.045 W / m * K;
- moisture absorption - more than 1% (depends on density);
- vapor permeability - 0.4-0.5 mg / hour * m * Pa;
- the maximum holding temperature is 450 C and above.
The analysis of the indicated values \u200b\u200bshows that the worst indicators of thermal conductivity of mineral wool are compensated by better vapor permeability, resistance to high temperatures and incombustibility. Using min. cotton wool is justified precisely in those conditions where the listed parameters are important.
The use of glass wool insulation is advisable to use in garages, workshops, industrial facilities, wherever there is an increased risk of fire. It is better to insulate damp rooms, such as saunas, baths and swimming pools with the help of mineral insulators, so in this case the vapor permeability of the insulator is important.
Environmental safety of insulation based on polystyrene and mineral wool depends on the conditions of use. Polystyrene derivatives can sustain combustion in the event of fires, while emitting toxic fumes. Mineral heat insulators are resistant to high temperatures and do not degrade, but over time they can age and release dust in the form of microfibers that make up the material. The external method of wall insulation with basalt wool is safe in this regard.
The thermal insulation design must take into account the possible impact of water. Mineral materials are susceptible to more fluid accumulation, while their thermal conductivity will be increased.
Features of thermal conductivity
Expanded polystyrene retains not only heat well, but also cold. Such possibilities are explained by its structure. The composition of this material constructively includes a huge number of sealed polyhedral cells. Each has a size from 2 to 8 mm. And inside each cell there is air, in the composition of 98%. It is he who serves as an excellent heat insulator. The remaining 2% of the total mass of the material falls on the polystyrene walls of the cells.
This can be seen if you take, for example, a piece of Styrofoam. 1 meter thick and 1 square meter area. Heat one side and leave the other side cold. The difference between temperatures will be tenfold. To obtain the thermal conductivity coefficient, it is necessary to measure the amount of heat that passes from the warm part of the sheet to the cold one.
People are used to being constantly interested in the density of polystyrene foam from sellers. This is because density and heat are closely related. Today, modern foam plastic does not require checking its density. The manufacture of improved insulation involves the addition of special graphite substances. They make the thermal conductivity of the material unchanged.
Comparative analysis of the main technical characteristics of basalt wool and expanded polystyrene
Fire resistance
In comparison with expanded polystyrene, basalt wool has a higher fire resistance. Basalt wool fibers are sintered at a temperature of about 1500 degrees. However, the maximum allowable temperature for using this thermal insulation material in the form of mats and slabs is limited due to the binders that were used in the formation of the finished products. At a temperature of about 600 degrees, binders are destroyed, and the basalt slab or mat loses its integrity. It should be noted that styrofoam without any consequences can withstand temperatures that do not exceed 75 degrees.
Flammability
Equally important are such indicators as flammability - the ability of a material to burn. Modern building materials are usually subdivided into:
- non-flammable (NG) - able to withstand the effects of very high temperatures without ignition, loss of strength, deformation of the structure and changes in other properties.
- combustible (G) - the degree of flammability is determined by such indicators as flammability, smoke-generating ability, flame spread, toxicity.
It is important to note that if materials of class NG are not only completely fireproof, but also prevent the spread of fire, then materials of class G always present a fire hazard.
The combustibility of basalt wool, which is based on inorganic materials that by their nature cannot burn, is determined depending on the amount of organic binders used in the production of insulation. High-quality basalt wool (for example, the Beltep trademark) contains no more than 4.5% binders, therefore it is assigned the NG group. In the case of a higher content of organic substances, the flammability group of basalt wool changes to the G1 group (slightly combustible materials) or G2 (moderately combustible materials).
Expanded polystyrene, regardless of the type of material, always belongs to class G. Moreover, the flammability group of this heat-insulating material can vary from G1 (slightly flammable material) to G4 (highly flammable material).
Water absorption
Basalt wool has open porosity, therefore it is able to absorb moisture (up to 2% by volume, and up to 20% by weight). And since water is an excellent conductor of heat, when moisture enters, the thermal insulation characteristics of basalt wool deteriorate significantly (up to complete unusability). And although manufacturers treat basalt wool with hydrophobic additives that prevent moisture absorption, experts recommend reliably protecting this thermal insulation material from moisture with vapor and waterproof barriers.
Unlike basalt wool, expanded polystyrene has a closed closed porosity, therefore it is characterized by a high resistance to capillary water absorption (up to 0.4% by volume) and diffusion of water vapor.
Strength
Strength characteristics mean such indicators as material tear strength, compression at 10% deformation, shear / shear, bending, etc.
Basalt wool strength characteristics depend on the density of the material and the amount of binders. In expanded polystyrene, these indicators depend solely on the density of the material. At the same time, expanded polystyrene is characterized by higher compressive strength at 10% deformation than basalt wool with a lower density (for example, the compressive strength at 10% deformation of expanded polystyrene with a density of 35-45 kg / m3 is about 0.25-0.50 MPa, while for basalt wool with a density of 80-190 kg / m3, this indicator ranges from 0.15-0.70 MPa). Note that for basalt wool with a density of 11-70 kg / m3, not strength characteristics are measured, but the value of compressibility under a load of 2000 Pa.
Thermal conductivity
One of the most important indicators of any thermal insulation material is its thermal conductivity. Studies have shown that both materials under consideration have almost the same thermal conductivity: for basalt wool - 0.033-0.043 W / m ° C, for expanded polystyrene - 0.028-0.040 W / m ° C. Note, moreover, that the lowest thermal conductivity has air (0.026 W / m ° C), and one and the second heat-insulating material is an effective insulation.
Thermal conductivity concept and theory
Thermal conductivity is the process of transferring thermal energy from heated parts to cold ones. Exchange processes occur until the temperature value is completely equilibrium.
A comfortable microclimate in the house depends on high-quality thermal insulation of all surfaces
The heat transfer process is characterized by a period of time during which the temperature values \u200b\u200bequalize. The more time passes, the lower the thermal conductivity of building materials, the properties of which are displayed in the table. To determine this indicator, such a concept as the thermal conductivity coefficient is used. It determines how much heat energy passes through a unit area of \u200b\u200ba given surface. The higher this indicator, the faster the building will cool down. The thermal conductivity table is needed when designing the protection of a building against heat loss. This can reduce the operating budget.
Heat loss in different parts of the building will differ
Thermal conductivity of foam from 50 mm to 150 mm is considered thermal insulation
Expanded polystyrene boards, colloquially called polystyrene, is an insulating material, usually white. It is made from thermal expansion polystyrene. In appearance, the foam is presented in the form of small moisture-resistant granules, in the process of melting at a high temperature it is melted into one whole, a plate. The sizes of the parts of the granules are considered from 5 to 15 mm. Outstanding thermal conductivity of 150 mm thick foam is achieved through a unique structure - granules.
Each granule has a huge number of thin-walled micro-cells, which in turn greatly increase the area of \u200b\u200bcontact with air. We can say with confidence that almost all of the foam consists of atmospheric air, approximately 98%, in turn, this fact is their purpose - the insulation of buildings both outside and inside.
Everyone knows, even from physics courses, atmospheric air is the main heat insulator in all heat-insulating materials, it is in a normal and rarefied state, in the thickness of the material. Heat saving, the main quality of the foam.
As mentioned earlier, the foam is almost 100% air, and this in turn determines the high ability of the foam to retain heat. And this is due to the fact that air has the lowest thermal conductivity. If we look at the numbers, we will see that the thermal conductivity of the foam is expressed in the range of values \u200b\u200bfrom 0.037W / mK to 0.043W / mK. This can be compared with the thermal conductivity of air - 0.027W / mK.
While the thermal conductivity of popular materials such as wood (0.12 W / mK), red brick (0.7 W / mK), expanded clay (0.12 W / mK) and others used for construction is much higher.
Therefore, foam plastic is considered to be the most effective material among the few for thermal insulation of external and internal walls of a building. Residential heating and cooling costs are significantly reduced thanks to the use of foam in construction.
The excellent qualities of polystyrene foam boards have found their application in other types of protection, for example: foam plastic, also serves to protect underground and external communications from freezing, due to which their operational life increases significantly. Polyfoam is also used in industrial equipment (refrigerating machines, refrigerating chambers) and in warehouses.
The main characteristics of heaters
We will provide, for starters, the characteristics of the most popular thermal insulation materials, which are the first to pay attention to when choosing. Comparison of heaters for thermal conductivity should be made only on the basis of the purpose of materials and conditions in the room (humidity, the presence of an open fire, etc.)
Comparison of building materials
Thermal conductivity. The lower this indicator, the less required a layer of thermal insulation, which means that the cost of insulation will also be reduced.
Moisture permeability. The lower permeability of the material to moisture vapor reduces the negative impact on the insulation during operation.
Fire safety. Thermal insulation should not burn and emit toxic gases, especially when insulating a boiler room or chimney.
Durability. The longer the service life, the cheaper it will cost you during operation, since it does not require frequent replacement.
Environmental friendliness. The material must be safe for humans and the environment.
Comparison of heaters by thermal conductivity
Expanded polystyrene (foam)
Plates of expanded polystyrene (foam)
It is the most popular thermal insulation material in Russia due to its low thermal conductivity, low cost and ease of installation. Polyfoam is made in plates with a thickness of 20 to 150 mm by foaming polystyrene and consists of 99% of air. The material has various densities, low thermal conductivity and moisture resistance.
Due to its low cost, expanded polystyrene is in great demand among companies and private developers for insulating various premises. But the material is quite fragile and quickly ignites, releasing toxic substances when burning. Because of this, it is preferable to use polystyrene in non-residential premises and for thermal insulation of unloaded structures - insulation of the facade under plaster, basement walls, etc.
Extruded polystyrene foam
Penoplex (extruded polystyrene foam)
Extrusion (technoplex, penoplex, etc.) is not affected by moisture and decay. It is a very durable and easy-to-use material that can be easily cut with a knife to the desired size. Low water absorption provides a minimum change in properties at high humidity, boards have high density and resistance to compression. Extruded polystyrene foam is fireproof, durable and easy to use.
All these characteristics, along with low thermal conductivity in comparison with other heaters, make Technoplex, URSA XPS or Penoplex slabs an ideal material for insulating strip foundations of houses and blind areas. According to the assurances of the manufacturers, an extrusion sheet 50 millimeters thick replaces a 60 mm foam block in terms of thermal conductivity, while the material does not allow moisture to pass through and you can do without additional waterproofing.
Mineral wool
Isover mineral wool slabs in packing
Minvata (for example, Isover, URSA, Technoruf, etc.) is made from natural materials - slag, rocks and dolomite using a special technology. Mineral wool has low thermal conductivity and is absolutely fireproof. The material is produced in plates and rolls of various hardness. For horizontal planes, less dense mats are used; for vertical structures, rigid and semi-rigid slabs are used.
However, one of the significant disadvantages of this insulation, like basalt wool, is its low moisture resistance, which requires additional moisture and vapor barrier when installing the mineral wool. Experts do not recommend using mineral wool for insulating wet rooms - basements of houses and cellars, for thermal insulation of a steam room from the inside in baths and dressing rooms. But even here it can be used with proper waterproofing.
Basalt wool
Rockwool basalt wool slabs in package
This material is produced by melting basalt rocks and blowing the molten mass with the addition of various components to obtain a fibrous structure with water-repellent properties. The material is non-flammable, safe for human health, has good performance in thermal insulation and sound insulation of premises. It is used for both internal and external thermal insulation.
When installing basalt wool, protective equipment (gloves, respirator and goggles) should be used to protect the mucous membranes from cotton wool microparticles. The most famous brand of basalt wool in Russia is the materials under the Rockwool brand. During operation, the thermal insulation slabs are not compacted or caked, which means that the excellent properties of low thermal conductivity of basalt wool remain unchanged over time.
Penofol, izolon (foamed polyethylene)
Penofol and Izolon are roll insulation with a thickness of 2 to 10 mm, consisting of foamed polyethylene. The material is also available with a foil layer on one side for a reflective effect. The insulation has a thickness several times thinner than the previously presented insulation, but at the same time it retains and reflects up to 97% of thermal energy. Foamed polyethylene has a long service life and is environmentally friendly.
Izolon and foil-clad penofol are light, thin and very easy-to-use heat-insulating material. Roll insulation is used to insulate damp rooms, for example, when insulating balconies and loggias in apartments. Also, the use of this insulation will help you save usable space in the room, while insulating it inside. Read more about these materials in the section "Organic thermal insulation".
Distinctive features of PPE insulation
Specifications
Thermal insulation made of polyethylene foam is a product with a closed-cell structure, soft and elastic, with a shape corresponding to its purpose. They have a number of properties that characterize gas-filled polymers:
- Density from 20 to 80 kg / m3,
- Operating temperature range from -60 to +100 0C,
- Excellent moisture resistance, at which moisture absorption is no more than 2% by volume, and almost absolute vapor tightness,
- A high rate of sound absorption even with a thickness greater than or equal to 5 mm,
- Resistance to most chemically active substances,
- Lack of rotting and fungal infection,
- Very long service life, in some cases reaching more than 80 years,
- Non-toxic and environmental friendly.
But the most important characteristic of polyethylene foam materials is a very low thermal conductivity, due to which they can be used for thermal insulation purposes. As you know, air retains heat best of all, and there is plenty of it in this material.
The heat transfer coefficient of a polyethylene foam insulation is only 0.036 W / m2 * 0C (for comparison, the thermal conductivity of reinforced concrete is about 1.69, drywall - 0.15, wood - 0.09, mineral wool - 0.07 W / m2 * 0C).
INTERESTING! Thermal insulation made of foamed polyethylene with a layer of 10 mm can replace the 150 mm thickness of brickwork.
Application area
Insulation made of foamed polyethylene is widely used in new and reconstruction construction of residential and industrial facilities, as well as in automobile and instrument making:
- To reduce heat transfer by convection and radiant heat from walls, floors and roofs,
- As reflective insulation to increase the heat transfer of heating systems,
- To protect pipe systems and pipelines for various purposes,
- In the form of an insulating gasket for various cracks and openings,
- For insulating ventilation and air conditioning systems.
In addition, polyethylene foam is used as a packaging material for the transportation of products that require thermal and mechanical protection.
Is polyethylene foam harmful?
Supporters of the use of natural materials in construction can talk about the harmfulness of chemically synthesized substances. Indeed, when heated above 120 ° C, foamed polyethylene turns into a liquid mass that can be toxic. But in standard living conditions, it is absolutely harmless. Moreover, insulation materials made of polyethylene foam are superior to wood, iron and stone in most parameters. Building structures with their use have lightness, warmth and low cost.
Thermal conductivity of polystyrene foam in comparison
If you compare foam with many other building materials, you can draw colossal conclusions.
The thermal conductivity index of the foam leaves from 0.028 to 0.034 watts per meter / Kelvin. If the density increases, the thermal insulation properties of extruded polystyrene foam without graphite additives decrease.
A 2 cm layer of extruded foam is able to retain heat, like a 3.8 cm layer of mineral wool, like a regular foam plastic, in a 3 cm layer, or like a wooden board, which is 20 cm thick.For bricks, these abilities are equivalent to a wall thickness of 37 cm. For foam concrete - 27 cm.
Indicators for different brands of expanded polystyrene
From the above simplified formula, we can conclude that the thinner the sheet of insulation, the less effective it is. But in addition to the usual geometric parameters, the final result is also influenced by the density of the foam, albeit insignificantly - only within the range of 1-5 thousandths. For comparison, let's take two slabs of similar brand:
- PSB-S 25 conducts 0.039 W / m · ° С.
- PSB-S 35 at a higher density - 0.037 W / m ° С.
But with a change in thickness, the difference becomes much more noticeable. For example, for the thinnest sheets of 40 mm with a density of 25 kg / m 3, the thermal conductivity index can be 0.136 W / m · ° С, and 100 mm of the same expanded polystyrene pass only 0.035 W / m · ° С.
Comparison with other materials
The average thermal conductivity of PSB lies in the range of 0.037-0.043 W / m · ° С, and we will focus on it. Here, foam plastic, in comparison with mineral wool made from basalt fibers, seems to win insignificantly - it has about the same performance. True, with twice the thickness (95-100 mm versus 50 mm for polystyrene). It is also customary to compare the conductivity of heaters with various building materials necessary for the construction of walls. Although this is not very correct, it is very clear:
1. Red ceramic brick has a heat transfer coefficient of 0.7 W / m · ° C (16-19 times more than that of foam). Simply put, to replace 50 mm of insulation, you will need masonry with a thickness of about 80-85 cm. Silicate and do not need less than a meter.
2. Solid wood is better in comparison with brick in this regard - here it is only 0.12 W / m · ° С, that is, three times higher than that of expanded polystyrene. Depending on the quality of the forest and the method of erecting the walls, a log house up to 23 cm wide can become the equivalent of a 5 cm thick PSB.
It is much more logical to compare styrenes not with mineral wool, brick or wood, but to consider closer materials - polystyrene and Penoplex. Both of them belong to expanded polystyrene and are even made from the same granules. But the difference in the technology of their "gluing" gives unexpected results. The reason is that styrene balls for the production of Penoplex with the introduction of blowing agents are simultaneously processed by pressure and high temperature. As a result, the plastic mass acquires greater homogeneity and strength, and air bubbles are evenly distributed in the plate body. Styrofoam, on the other hand, is simply steamed in a mold, like popcorn, so the bonds between the expanded granules are weaker.
As a result, the thermal conductivity of Penoplex - the extruded "relative" of PSB - also noticeably improves. It corresponds to values \u200b\u200bof 0.028-0.034 W / m · ° С, that is, 30 mm is enough to replace 40 mm of foam. However, the complexity of production also increases the cost of EPS, so you should not count on savings. By the way, there is one curious nuance here: usually extruded polystyrene foam loses a little in efficiency with increasing density. But when graphite is added to Penoplex, this dependence practically disappears.
Prices for polystyrene sheets 1000x1000 mm (rubles):
What you need to know about the thermal conductivity of foam
The ability of a material to transfer heat, conduct or retain heat fluxes is usually estimated by the coefficient of thermal conductivity. If you look at its dimension - W / m ∙ С о, it becomes clear that this is a specific value, that is, determined for the following conditions:
- The absence of moisture on the surface of the slab, that is, the coefficient of thermal conductivity of foam from the reference book, is a value determined in ideally dry conditions, which practically do not exist in nature, except in the desert or in Antarctica;
- The value of the coefficient of thermal conductivity is reduced to a foam plastic thickness of 1 meter, which is very convenient for theory, but somehow not impressive for practical calculations;
- The results of measurements of thermal conductivity and heat transfer were made for normal conditions at a temperature of 20 ° C.
According to a simplified technique, when calculating the thermal resistance of a layer of foam insulation, it is necessary to multiply the thickness of the material by the coefficient of thermal conductivity, then multiply or divide by several coefficients used in order to take into account the actual operating conditions of the thermal insulation. For example, strong flooding of the material, or the presence of cold bridges, or a method of installation on the walls of a building.
How much the thermal conductivity of foam differs from other materials can be seen in the comparison table below.
In fact, not everything is so simple. To determine the value of thermal conductivity, you can make it yourself or use a ready-made program to calculate the parameters of insulation. For a small object, this is usually done. A private trader or self-builder may not be interested in the thermal conductivity of the walls at all, but lay insulation from foam material with a margin of 50 mm, which will be quite enough for the most severe winters.
Large construction companies that insulate walls on an area of \u200b\u200btens of thousands of squares prefer to act more pragmatically. The performed calculation of the thickness of the insulation is used to compile an estimate, and the real values \u200b\u200bof thermal conductivity are obtained on a full-scale object. To do this, several polystyrene sheets of different thickness are glued to the wall section and the real thermal resistance of the insulation is measured. As a result, it is possible to calculate the optimal thickness of the foam with an accuracy of several millimeters, instead of an approximate 100 mm of insulation, you can put the exact value of 80 mm and save a considerable amount of money.
How profitable is the use of foam in comparison with typical materials can be estimated from the diagram below.
Use of thermal conductivity values \u200b\u200bin practice
Materials used in construction can be structural and heat insulating.
There are a huge number of materials with thermal insulation properties.
The greatest value of thermal conductivity is in structural materials that are used in the construction of floors, walls and ceilings. If you do not use raw materials with heat-insulating properties, then to preserve heat, you will need to install a thick layer of insulation for the construction of walls.
Often simpler materials are used to insulate buildings.
Therefore, when building a building, it is worth using additional materials. In this case, the thermal conductivity of building materials is important, the table shows all the values.
In some cases, insulation outside is considered more effective.
What is the thermal conductivity of foam Properties and characteristics
Thermal conductivity is a value that denotes the amount of heat (energy) passing through 1 m of any body per hour at a certain temperature difference from one side to the other. It is measured and calculated for several reference operating conditions:
- At 25 ± 5 ° C, this is a standard indicator, enshrined in GOST and SNiP.
- "A" - this is the designation for dry and normal indoor humidity.
- "B" - this category includes all other conditions.
The actual thermal conductivity of foam granules pressed into a lightweight slab is not as important in itself as in conjunction with the thickness of the insulation. After all, the main goal is to achieve the optimal level of resistance of all layers of the wall in accordance with the requirements for a particular region. To obtain the initial figures, it will be enough to use the simplest formula: R \u003d p ÷ k.
- Heat transfer resistance R can be found in special tables of SNiP 23-02-2003, for example, for Moscow they take 3.16 m ° C / W. And if the main wall does not reach this value in terms of its characteristics, the difference should be covered by the insulation (mineral wool or the same foam).
- Indicator p - denotes the desired thickness of the insulating layer, expressed in meters.
- The coefficient k - just gives an idea of \u200b\u200bthe conductivity of bodies, which we are guided by when choosing.
The thermal conductivity of the material itself is checked by heating one side of the sheet and measuring the amount of energy transferred by conduction to the opposite surface per unit of time.
Features of the production of basalt wool and expanded polystyrene
The production of basalt wool is based on the melted rocks of the gabbro-basalt group. The melting takes place in furnaces at temperatures above 1500 degrees. The resulting melt is transformed into thin fibers, from which a mineral wool carpet is formed. Then the mineral wool carpet is treated with binders and heat treatment is carried out in a polymerization chamber, resulting in finished products - mats and slabs.
Expanded polystyrene is a lightweight gas-filled material based on polystyrene, which is characterized by a uniform structure, consisting of small (0.1-0.2 mm) completely closed cells. Today the construction market offers two types of this material: regular and extruded polystyrene foam. The main difference between these two types of polystyrene foam is the production technology, and, as a result, the properties of the finished product.
Ordinary polystyrene foam is formed by sintering granules at high temperatures.
Extruded polystyrene foam is made by expanding and welding granules under the influence of hot steam or water (temperature 80-100 degrees) and then extruding through an extruder.
The main difference between extruded polystyrene foam and conventional foam is higher stiffness and lower water absorption. Another difference is due to the production technology - the limitation of the thickness of the plates (maximum 100 mm), made of extruded polystyrene foam.
Thermal conductivity of foam
The main characteristic, thanks to which expanded polystyrene has received wide recognition as a material for insulation No. 1, is the ultra-low thermal conductivity of the foam. The relatively low strength of the material is more than offset by such advantages as resistance to most aggressive compounds, light weight, non-toxicity and safety during work. The good heat-insulating properties of foam make it possible to equip home insulation at a relatively low price, while the durability of such insulation is designed for a period of at least 25 years of service.
The main types of insulation used to reduce heat loss
The following types of insulators are used to carry out thermal insulation measures of any kind:
- extrusion polystyrene foam (XPS), refers to polystyrene derivatives (represented by various manufacturers, has many brands);
- polystyrene, its production also implies processing of polystyrene, but using a different technology (it has a sufficient number of manufacturers, the breakdown by brands is not clear, it is positioned as "foam").
- mineral or basalt wool, fundamentally different from polystyrene products and is the main competitor of foamed polystyrene (represented on the market of insulating products by a large number of manufacturers).
The number of manufacturing companies, both domestic and foreign, is measured in dozens. When choosing a product, you need to rely on the physical properties of each individual product.
Styrex or penoplex
Styrex is extrusive polystyrene foam, like penoplex. At its core, the applicability of styrex is justified where the applicability of penoplex is, that is, there are no decisive differences. Preference can be given to one material, only if it is convenient to cut a given dimension of boards, to reduce waste and in the case of increased strength requirements, since styrex has better bending strength.
Physical properties of styrex:
- density - 0.35-0.38 kg / m3;
- thermal conductivity - 0.027 W / m * K;
- moisture absorption, no more - 0.2%;
- compressive strength - 0.25MPa;
- bending strength - 0.4-0.7;
- vapor permeability - 0.019-0.020mg / hour * m * Pa.
At large deltas of external and internal temperatures, a slightly lower thermal conductivity of styrex makes this material more profitable, but with an average difference of 0.003 W / m * K this will be hardly noticeable.
The production of heaters under the Styrex trademark is located in Ukraine.
Yes, in our country, unlike countries with hot climates, there are fierce winters. That is why you need to be built from warm materials using special insulation. Otherwise, all the expensive heat from boilers and stoves will go through walls and other ceilings.
We need to know exactly which of the modern popular materials for insulation are the most effective.
What is thermal conductivity?
Thermal conductivity can be described as heat transfer process before thermal equilibrium occurs. The temperature, one way or another, will be leveled, the only question is the speed of this process. If we apply this concept to a home, then it is clear that the longer the temperature inside the building equalizes with the outside, the better. Simply put, how quickly the house cools down is a matter of what the thermal conductivity of its walls is.
In numerical form, this indicator is characterized by thermal conductivity coefficient... It shows how much heat per unit of time passes through a unit of surface. The higher this coefficient of the material, the faster it conducts heat.
Thermal conductivity of heaters is the most informative indicator, and the lower it is, the more efficiently the material retains heat (or coolness on hot days). But there are other indicators that affect the choice of insulation.
Thermal conductivity table of heaters
The table shows data on the most widely used heaters that are used in private construction: mineral wool, expanded polystyrene, polyurethane foam and polystyrene foam. Comparative data for other species are also provided.
Thermal conductivity table of heaters
| Thermal conductivity, W / (m * C) | Density, kg / m 3 | Water vapor permeability, mg / (m * h * Pa) | «+» | «-» | Combustible. |
| Polyurethane foam | 0,023 | 32 | 0,0-0,05 | 2.Seamless installation with foam; 3.Long-term; 4.Best thermal and waterproofing | 1. inexpensive 2. Not resistant to UV radiation | Self-extinguishing |
| 0,029 | 40 | |||||
| 0,035 | 60 | |||||
| 0,041 | 80 | |||||
| Expanded polystyrene (foam) | 0,038 | 40 | 0,013-0,05 | 1.Excellent insulates; 2. Cheap; 3. Moisture proof | 1. Fragile; 2. Does not "breathe" and forms condensation | |
| 0,041 | 100 | |||||
| 0,05 | 150 | |||||
| Extruded polystyrene foam | 0,031 | 33 | 0,013 | 1.Very low thermal conductivity; 3. Waterproof; 4.Compression resistant; 5. Does not rot or mold; 6. Operation from -50 ° С to + 75 ° С; 7.Convenient to install. | 1. Much more expensive than polystyrene; 2. Susceptible to organic solvents; 3. Low vapor permeability, condensation forms. | G1 for brands with antifoam additives, others G3 and G4. Fire resistance and self-extinguishing |
| Mineral (basalt) wool | 0,048 | 50 | 0,49-0,6 | 1.Good vapor permeability - "breathes"; 2.Resists fungi; 3.Soundproofing; 4.High thermal insulation; 5. Mechanical strength; 6.Does not crumble | 1.Inexpensive | Refractory |
| 0,056 | 100 | |||||
| 0,07 | 200 | |||||
| Fiberglass (glass wool) | 0,041-0,044 | 155-200 | 0,5 | 1.Low thermal conductivity; 2.During fires does not emit toxic substances | 1. Over time, thermal insulation decreases; 2.Mold may appear; 3. Problematic installation: the fibers crumble and harm the skin, eyes; 4. Low vapor permeability, forms condensation. | Does not burn |
| PVC foam | 0,052 | 125 | 0,023 | 1.Rigid and easy to install | 1. Short-lived; 2.Poor vapor permeability and condensation | G3 and G4. Fire resistance and self-extinguishing |
| Sawdust | 0,07-0,18 | 230 | - | 1. Cheapness; 2.Environmental friendliness | 1. To deteriorate and rot; 2.Thermal insulation properties drop at high humidity | Fire hazard |
Comparison of "+" and "-" will help to determine which insulation to choose for specific purposes.
Useful indicators of insulation
What are the main indicators you need to pay attention to when choosing a heater:
Who is the warmest in the world?
The purpose of such a thorough study of insulation is one - to find out which one is the best. However, this is a double-edged sword, as materials with high thermal insulation may have other undesirable characteristics.
Polyurethane foam or extruded polystyrene foam
It is easy to determine from the table that the champion in thermal insulation is polyurethane foam... But its price is much higher than that of polystyrene or foam. This is because it possesses two of the most demanded qualities in construction: incombustibility and water-repellent properties. It is difficult to set it on fire, so the fire safety of such insulation is high, moreover, it is not afraid to get wet.
But polyurethane foam has a real alternative - extruded polystyrene foam. In fact, this is the same foam, but it has undergone additional processing - extrusion, which has improved it. It is a material with a uniform structure and closed cells, which is presented in the form of sheets of different thicknesses. It is distinguished from conventional foam by its enhanced strength and ability to withstand mechanical pressure. That is why it can be called a worthy competitor to polyurethane foam. The only drawback of installing individual plates is the seams, which are successfully sealed with polyurethane foam.
And what is more convenient for you to use - liquid insulation from a spray can or plates, it's up to you to choose. But remember that these materials do not "breathe" and can form the effect of misted windows, so that all insulation can leave the window during ventilation. Therefore, such materials should be insulated reasonably.
Mineral wool or foam
If we compare mineral wool and polystyrene, then their thermal conductivity is at the same level ≈ 0.5. Therefore, choosing between these materials, it would be nice to evaluate other qualities, such as water permeability. So, the installation of cotton wool in places with possible wetting is undesirable, since it loses its thermal insulation properties by 50% when wet by 20%. On the other hand, cotton wool "breathes" and lets in steam, so that no condensation will form... In the house, which is insulated with basalt fiber wool, the windows will not fog up. And cotton wool, unlike foam, does not burn.
Other heaters
Eco-friendly materials such as sawdust are now very popular, which are mixed with clay and used for walls. However, a material as pleasant at a price as sawdust has many disadvantages: it burns, gets wet and rots. Not to mention the fact that by gaining moisture, sawdust loses its insulating properties.
Also, cheap and environmentally friendly foam glass is gaining popularity, which can be used only without loads, since it is very fragile.
Choosing insulation
Energy prices are rising, and at the same time, the popularity of insulation is growing. Our article presents a table of thermal conductivity of materials for insulation and comparative analysis popular types of insulation. The main thing I would like to note is that you will get good performance by purchasing only a high-quality certified product. The choice of thermal insulation materials on the market is very wide and one type of insulation is offered by more than five manufacturers. Many of them may upset you with their quality, so be guided by the reviews of those who have tested specific brands on their own skin.
Saving heat in the house is a special function of building and furnishing a home. But what materials are the most modern, high-quality, at the same time affordable and easy to install? It is impossible to answer this question unambiguously, but the comparative characteristics given below will help to understand this issue.
Description and comparison of heaters
Today the consumer can choose a material, the properties of which satisfy his needs to one degree or another. The installation of insulation also depends on what choice you make - whether you can handle it yourself, or you will have to call specialists. The structure and texture of materials matters.
Based on this criterion, we can distinguish:
- Plates - are building materials of different densities and thicknesses, which are made by gluing and pressing;
- Foam blocks - made of concrete, with the inclusion of special additives, the porous structure is obtained as a result of a chemical reaction;
- Vata - sold in rolls, has a fibrous structure;
- Crumbs or granules - a free-flowing compactor includes foam substances of various fractions.
The properties, cost and functionality of the material are what you pay attention to. Typically, the material indicates which surface it is intended for. Raw materials for insulation can be different, but in general it can be organic and inorganic.
Organic insulation is made on the basis of peat, wood and reeds. Inorganic insulation materials are minerals, foamed concrete, substances containing asbestos, etc. It is worth learning how to evaluate and understand the properties of various substances.
Insulation properties: thermal conductivity, etc.
How effective this or that material is depends on three main characteristics - density, hygroscopicity, thermal conductivity. Thermal conductivity is perhaps the main indicator of material quality. This property is calculated in watts per square meter. This indicator is also influenced by such a parameter as moisture absorption.
Density - the higher the porous material has, the more efficiently heat is retained inside the building. Usually this indicator is decisive if you are looking for insulation for walls, roofs or floor slabs. Hygroscopicity is called resistance to moisture. The same basement floors must be reinforced with materials with very low hygroscopicity. This will be, for example, plastiforms.
Comparison table of heaters
To show clearly and schematically what kind of insulation, figuratively speaking, what is worth, to compare, it is easier to depict it in a table. Here are the most popular heaters. They are assessed in categories such as the above thermal conductivity, hygroscopicity and density.
|
Material |
Thermal conductivity |
Hygroscopicity |
Density (kg / m3) |
|
Mineral wool |
|||
|
Expanded polystyrene |
Very low |
||
|
Expanded clay |
|||
|
Plastiform |
Very low |
||
|
Styrofoam |
Very low |
||
|
Penoplex |
|||
|
Aerated concrete |
|||
|
Basalt fiber |
Styrofoam can be considered a kind of leader in the rating of insulation materials. Availability and quite an inexpensive price will also be competitive here. But it would be incorrect to advise one thing, not knowing the situation, the area of \u200b\u200binsulation, financial capabilities, the amount of work, etc.
By thickness: comparison of thermal conductivity of building materials
There are many tables where such an important indicator as the thickness of the insulation is mentioned. Indeed, a lot depends on this, because the thickness of this layer also "eats" the space and affects the result. In this material, you can make a start on how thick in centimeters the minimum layer of one or another insulation will be.
Minimum layer (thickness) of insulation:
- Plastiform - 2 cm;
- Penofol - 5 cm;
- Styrofoam and expanded polystyrene - 10 cm;
- Foam glass - 10-15 cm;
- Minvata - 15 cm;
- Basalt fiber - 15 cm;
- Penoplex and expanded clay - 20 cm;
- Aerated concrete - from 20 to 40 cm.
Of course, it is important what exactly you need insulation for. For example, with expanded clay you can only insulate floors and floors between floors. Also remember that a rare insulation will do without hydro and vapor barrier.
Nuances of using heaters
There are some useful recommendations that can be taken into account when choosing a heater and subsequent installation. For example, for floors and ceilings, that is, horizontal surfaces, you can use literally any material. However, an additional layer with high mechanical strength should be used - this is a prerequisite.
If we talk about basement floors, then they need to be insulated with building materials of low hygroscopicity. High humidity is also taken into account. If this is not done, the insulation may partially and completely lose its properties under the influence of moisture.
Well, for walls (vertical surfaces), you need to use materials in the form of plates or sheets. If you choose roll material or bulk material, then over time the materials will definitely begin to sag. This means that the fastening method must be flawless. And this is a separate topic.
Comparative table of thermal conductivity of materials and heaters (video)