For what thermal insulation is necessary? Types and properties of materials
Energy carriers rise in price not on days, and on hours, and in it the reason of the growing interest in the questions connected with energy saving, in particular, to a possibility of use of the heat-insulating materials.
Heatlosses through walls of a usual multystoried house make 30 - 40% of the allocated heat. Traditional construction materials are not capable to store it effectively. Special heat-insulating materials are necessary.
Thermal insulation is urged to provide a comfortable microclimate in rooms, to reduce losses of heat from within the building and to limit receipt of excess heat outside that promotes normal operation of conditioners.
A side effect of application of thermal insulation is sound insulation of the building that leads to reduction of extraneous noises, increase of comfort of housing.
Use of thermal insulation allows to cut considerably a consumption of construction materials and to reduce the mass of designs. Approximately 10 - the centimetric heat-insulating plate on heat conductivity is equivalent to a bricklaying 1,5 - 1,8 m thick
Thermal insulation allows to reduce expenses on heating of buildings and, respectively, to reduce the number of emissions of carbon dioxide and other products of combustion in the atmosphere. And it, in turn, leads to the general improvement of an ecological situation and decrease in greenhouse effect. Why it is more favorable to
to place thermal insulation outside?
of the Wall can be warmed as outside, and from within the building. However warming of buildings outside has a number of indisputable advantages:
- external thermal insulation shifts a dew point in an external heat-insulation layer thanks to what protects walls from condensation and freezing of moisture in a wall;
- smoothes daily and seasonal fluctuations of temperature of walls, from - for it temperature deformations decrease that, in turn, excludes formation of cracks in walls. It is especially important when using large panels;
- external thermal insulation allows to hide outer defects of walls and to improve appearance of the repaired or reconstructed buildings;
- if to place thermal insulation outside, but not inside, it will not affect the size of useful area of rooms;
- at placement of thermal insulation it is outside facilitated devices of engineering communications and an electrical wiring.
It is known that brick walls at shutdown of a source of heat cool down by 6 times more slowly if thermal insulation is placed outside, but not inside.
Conclusion: internal thermal insulation should be applied only at impossibility of use of external.
of the Requirement to heat-insulating materialsimpose on
In each separate case depending on service conditions of heat-insulating material special requirements to it.
The main characteristic of heat-insulating materials is heat conductivity - ability to transfer warmth. It depends on density of material, quantity and the size of a time, humidity of material and many other factors.
On heat conductivity materials subdivide into classes:
And - low (to 0,06 W / m*k);
B - average (0,06 - 0115 W / m*k);
In - raised (over 0,115 - 0,175 W / m*k).
For effective thermal insulation of facades materials have to meet the following requirements:
- to have durability sufficient to sustain plaster weight;
- to have rather high vapor permeability, but low water absorption;
- to meet requirements of fire safety, to be frost-resistant and biostable.
the heat-insulating materials classify Types of the heat-insulating materials By structure of initial raw materials on three look:
- organic - gas-filled plastic (polyfoams, poroplasta, etc.) and products on the basis of woodworking waste (DVP, a chipboard), agricultural waste (solomit, kamyshit);
- inorganic - glass wool, mineral wool and mineral-cotton plates, foam concrete, foamglass, vspuchenny perlite;
For external warming of facades the greatest application was received by mineral wool and expanded polystyrene. We will also consider them in the following part of article.