Thermal conductivity of foam and its thermal conductivity in the insulation of a private house. Many people talk about this characteristic, but they understand little about what is at stake. Of course, this is very important, but how to obtain thermal conductivity?
In fact, the conversation is about the fact that the insulation will not allow the transfer of heat and energy through the area that it covers, namely, we are talking about low thermal conductivity. The thermal conductivity coefficient of polystyrene is the main characteristic that determines the procedure for use in the insulation of structures and buildings of various types.
All of its properties, both positive and negative, foam (and in another way it is also called expanded polystyrene foam) owes styrene and a special technological production chain.
For a start, styrene is saturated with air or gas, and granules are made of it, which are empty inside. Further, under the action of steam, the volume of the granules is increased many times with sintering in the presence of a binder in the composition. So, we get a sheet of small balls of the same shape, which are filled with gas.
Although the walls of their styrene are thin, they are quite strong. And even if you put in enough effort, it will not be easy to destroy the integrity of the shell.
The gas that is trapped inside will remain stationary under all conditions of use, and thus provide a low thermal conductivity of the foam and the area that it will cover.
The final fullness depends on the density. This value can vary from 92% to 98%. Note that the higher the percentage, the lower the density, which means that the material will be lighter, the thermal conductivity is higher, and the quality of insulation will also be better.
To fully understand the phrase "thermal conductivity of foam", for clarity, you can use the physical dimension.
This value is measured in W / m * h * K. It is deciphered as follows - the number of watts of thermal energy that will pass through the thickness of the material with an area of 1m 2 per hour when the temperature of the heated surface drops by 1 Kelvin.
"1 Kelvin = 1 degree Celsius"
What is the pattern of heat leakage through the insulation
Among the characteristics of the technical type, the different density of the material is reflected in the coefficient of thermal conductivity of the foam. This indicator can range from 0.033 to 0.
041 units. As the density increases, the value (ratio) becomes smaller.
But even with an infinite increase in density, it is impossible to achieve losses that will be equal to zero. With the transition of the shaped boundary and a further increase in density, we will only get an increase in heat loss, which on the graph has the form of a jump. It is also important to understand that with an increase in the density level, the amount of gas and the volume of the material will decrease, which means that the thermal insulation will be worse.
Through experiments, it was deduced that the ability of the insulator to retain heat reached such a maximum value - from 7 to 36 kg / m 3 . This number, which is indicated on the packaging, lets you know how much one cubic meter of insulation will weigh at the specified density. If the density is low, the weight will also be small. And this is a separate advantage when laying and installing.
To represent this physical quantity in reality, try to compare other building materials with foam.
For example, you stand and examine the sections of walls from all kinds of materials from the ends. To begin with, you see concrete masonry, the thickness of which is 3.2 meters, then brickwork of five bricks, 1.25 meters thick, then a rather thin wooden partition, the width of which will be about 0.4 meters.
And at the very end there will be a sheet of foam, which is only 10 cm thick! But what is common among all these materials? Only one thing - the same coefficient of thermal conductivity.
So, when using low thermal conductivity, you can decently reduce the consumption of expensive materials that are used for installation, installation and cladding. A house built with 2.5 bricks will be as reliable as a house with 5 bricks, but in the first case, the heating consumption will be higher. If you want a warmer home, all you need to do is insulate the wall 5 cm with a foam board.
Experience the whole difference! This is pure savings.
When choosing foam for thermal conductivity who -this may decide that the comparison above is incorrect. It is impossible to compare materials that are very different among themselves, both in composition and in origin. Then let's see and compare using the example of modern and popular heaters: basalt (mineral), extruded and foamed polystyrene foam, polyurethane foam.
But the comparison obtained does not favor the materials listed above, since the level of their heat capacity is almost 1.
4 times higher than that of simple foam. This significantly reduces the consumer value, and puts the materials down a notch.
Comparison of extruded polystyrene foam and polystyrene foam in terms of thermal conductivity is not an easy task. This is due to the fact that the mathematical and physical indicators are almost the same. But when determining leadership in the form of a low coefficient of thermal conductivity of expanded polystyrene, foam has a huge advantage in the form of a low price, which is 3-4 times lower.
And even in comparison of polyurethane and foam in thermal conductivity, we can say that expanded polystyrene perfectly "holds a punch". The coefficient of polyurethane foam is only 30% less, but the price. Do not forget that installation requires at least minimal qualifications and the availability of special equipment, and this will require additional costs.But foam insulation can be done with your own hands, even if you have not been involved in construction work up to this point. As you can see, there is something to think about before making a choice.
PSB-S-15. This is a material that has a low density and a high level of thermal conductivity. It is used to insulate vertical structures indoors. This is expanded polystyrene with the number "15" in the marking. Differs in small thickness.
Insulation with the number "25" can be used to insulate walls from the outside, as well as for attic and basement floors, roofs (flat and pitched) and in private houses and for high-rise buildings.
The material marked in the title "35" has the highest available density. It perfectly insulates deepened foundations, car roads, as well as takeoff and landing lanes.
And most likely there is no material that cannot be insulated with foam. Provided that thermal insulation cannot be seen with the naked eye, this does not mean that it does not exist.
You can verify this if you receive an electricity bill the next month after installation.
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