Define construction of exterior walls.It depends on the following factors: climatic, economic, structural and other features of the object.Finish the surfaces of external walls (internal and external).Driving exterior and interior finishing solutions depends on the exterior and interior of the building.It automatically adds several layers of thick walls of the house.
Calculate the resistance to heat transfer of the selected wall (Rpr.) This value can be found from the formula, when it is necessary to know the material of construction of the wall, and its thickness: Rpr. = (1 / α (c)) + R1 + R2 + R3 + (1 / α (n)), whe
re R1, R2, R3 - resistance to heat each wall layer, α (a) - heat transfer coefficient of the inner wall surface, α (n) - the heat transfer coefficient of the outer surface of the wall.
Calculate the minimum allowable value of thermal resistance (Rmin.) For the climate zone where construction is according to the formula R = δ / λ, δ - thickness of the material in meters, λ - thermal conductivity (W / m *K).Thermal conductivity can be seen on the packaging material and identified by a special table thermal conductivity material, such as foam PSB-C 15, a density of 15 kg / m3, it is equal to 0.043 W / m, for mineral wool density 200 kg / m3, - 008 W / m.
Thermal conductivity - Ability of the material to exchange heat with the environment.The higher the thermal conductivity, the material cooler.The highest thermal conductivity in reinforced concrete, metal, marble, lower - of air.Thus, materials which are based on air, for example, polystyrene are extremely warm.40 mm foam = 1m brickwork.The coefficient has a constant value for each climate zone, it can be found in the directory DBN V.2.6-31: 2006 (Thermal insulation of buildings).
compare Rmin.with Rpr.and find the difference Δ R. If the result of the calculation Rmin. & lt;or = Rpr., the wall insulation is not necessary, because the existing regulatory layers provide insulation.When Rmin. & Gt; Rpr., Determine the difference between them, subtract the smaller value from the larger ΔR = Rmin.- Rpr.
Pick thickness of insulation according ΔR.This insulation must be selected to provide the missing heat transfer resistance.Choosing insulation material should be aware of the following its characteristics, such as thermal conductivity, water absorption coefficient, density, flammability class.The coefficient of water absorption - the material's ability to hold water soaked.The smaller the value is of more interest to this material as insulation.In the construction materials are used with a high coefficient of water absorption, for example, glass wool or mineral wool.Additionally, in this case, a steam and waterproofing.This makes it necessary not to allow the material to get wet.If this happens, the coefficient of thermal conductivity is strongly increased, for example, mineral wool twice.
It is also important class of combustibility and density insulation.Last characterizes the load on the supporting structures.Building materials are divided into combustible and non-combustible, which are divided into 4 groups: readily flammable (G1);umerennogoryuchie (T2);normalnogoryuchie (G3);silnogoryuchie (T4).The denser the material, the less flammable, so its cost is higher.After selecting the material, calculate the thickness of the insulation according to the formula: ΔR = δ / λ, where δ = λ / ΔR, δ is the desired thickness of the chosen insulation, expressed in meters.