Determination of wall dew point temperature. Dew point in a wall - what is it, how to calculate and find

The dew point is the air cooled to certain temperature, in a state in which steam begins to condense and turn into dew. In general, this parameter depends on the air pressure indoors and outdoors. Determining the value is not always easy, but it is necessary to do this, since this is one of the most important factors in construction and for a comfortable life and human existence in the room.

If the dew point is too high, concrete, metal, wood and many other building materials will not give the desired effect when building or renovating a house and will not last long. When laying polymer floors, if condensation gets on the surface of the material, defects such as swelling of the floor, shagreen, peeling of the coating and much more may occur in the future. It is impossible to visually determine the parameter in the room; for this you need to use a non-contact thermometer and a table.

What factors influence

• the thickness of the wall in the room and what materials were used for insulation;
• temperature, in different parts around the world it is different and the temperature coefficient of the north from the south is very different;
• humidity, if the air space contains moisture, the dew point will be higher.

To understand more clearly what it is and how the value can be affected by certain factors, let’s look at an illustrative example:

1. Uninsulated wall in the room. The dew point will shift depending on the weather conditions outside. In case of stable weather without sharp fluctuations, the dew point will be closer to external wall, towards the street. In this case, there are no harmful indicators for the premises itself. If a sharp cold snap occurs, the dew point will slowly move closer to the inside of the wall - this can lead to the room being saturated with condensation and the wall surfaces slowly getting wet.
2. Externally insulated wall. The dew point has a position inside the walls (insulation). When choosing a material for insulation, you should count on this factor and correctly calculate the thickness of the selected material.
3. Wall insulated from the inside. The dew point is between the center of the wall and the insulation. Is not the best option, if the weather conditions are too humid, since with a sharp cold snap, in this case the dew point will sharply move to the junction between the insulation and the wall, and this in turn can lead to disastrous consequences for the wall of the house itself. It is possible to insulate a wall from the inside in a humid climate if there is good system heating system, which is able to maintain an even temperature in each room.

If the home renovation is done without taking into account weather conditions, it will be almost impossible to eliminate the problems that have arisen; the only way out is to start the work again and clean up everything that has been done, which entails a lot of spending money.

How to correctly determine and calculate (table and formula)

Dew point can be affected by temperature and humidity

It is quite difficult for a person to live in comfort with high humidity. Condensation causes problems both for health (there is a chance of developing asthma) and for the house itself, especially for its walls. High humidity can cause the ceiling and walls to become covered with mold that is harmful to humans and difficult to remove; in rare cases, it is necessary to completely replace the walls and ceiling in order to kill all harmful microorganisms present.

In order to prevent this from happening, you should make a calculation and find out whether it is worth undertaking repairs in a particular building, insulating the walls, or even building housing in this place. It is important to know that for each building the dew point is individual, which means that its calculation will be carried out with slight differences.

Before starting the calculation, you should take into account such factors as: climatic conditions in a particular region, the thickness of the walls and the material from which they are made, and even the presence of strong winds. Absolutely all materials contain low, permissible humidity; a person should make sure that this humidity does not increase and a dew point does not form. When you call a specialist to measure the value in case of high humidity, you will most likely be given the answer that the thermal insulation of the house was not done correctly, the thickness of the material is not suitable, or an error was made during installation. To some extent, this person will be right, since it is the correct repairs in the house that have a greater impact on the change in dew point and the appearance of condensation on the walls.

Table: indicators for determining dew point

Schedule

Thanks to the graph, you can determine the optimal indicators

How to calculate: necessary tools and sequence of actions

• thermometer;
• hygrometer;
• non-contact thermometer (can be replaced with a regular one).

Formula for calculations in frame, brick, multi-layer walls with insulation

To calculate the dew point with insulation, the following formulas are used: 10.8 °C

Using the obtained indicators, draw up a graph with the temperature range T1 placed in the wall and the remaining °C for the insulation. IN in the right place mark the dew point.

What to do if the value is defined incorrectly?

Let's consider the places where the dew point can be located in an uninsulated wall:

• Closer to the outer surface of the wall. In this case, the appearance of dew point in the house is minimal; as a rule, the inner wall remains dry.
• Closer to the inner surface of the wall. In this case, condensation may appear when it gets cold outside.
• In the rarest cases, the dew point is on the inside wall of the building. In this case, it is almost impossible to get rid of it, and most likely the walls in the house will be a little damp all winter.

In these cases, the problem can be solved by adding layers of vapor barrier to the walls. This will help retain water vapor so that it does not pass through the walls into the room, which will prevent dew points from appearing on the walls and ceiling. If the climate is too cold and the temperature stays more than minus 10 degrees most of the year, it is worth considering the option of forcing heated air into the room. This can be done using a heat exchanger or air heater.

Video: why condensation and mold appear on the walls

It is important to correctly determine the dew point during the construction phase. This will help to properly insulate the wall and further avoid the appearance of condensation and mold in the house.

Wall insulation is one of the main issues during construction. At first glance, it may seem that it is very simple to solve it - choose the one that suits the climatic conditions and finances, and insulate it. However, it is not. There are a number technical specifications, which must be completed so that the walls of the house do not become damp inside or freeze outside during the cold season. One of these conditions is to insulate the house so that the dew point is closer to the outer wall, and in no case - inside the house. To do this, you need to be able to determine where the dew point will be located at different conditions to eliminate the possibility of condensation forming on the walls inside the room.

What is dew point

The dew point is an indicator of the temperature at which maximum saturation of air with steam occurs and it begins to condense. This indicator depends on two main factors: temperature and air humidity.

When at least one of these two quantities changes, the dew point also changes, that is, it constantly moves, just as the temperature and humidity of the air are not constant all the time.

There is a table of dew points at different temperatures and air humidity, developed by specialists. From it you can see under what conditions steam begins to condense. For example, in winter time at a standard indoor air temperature of +20 0 C and humidity from 50% to 60%, the dew point will range from 9.3 0 C to 12 0 C. That is, condensation should not form inside the room, since under these conditions there are no surfaces with this temperature.

Let's look further. If the house is +20 0 C, and the temperature outside is -20 0 C, then in the wall there will be a dew point with a temperature of +12 0 C at a relative humidity of 60%. The dew point can move across the thickness of the wall depending on the temperature inside and outside the room, as well as the humidity in the wall itself. The closer the dew point is to the inner surface, the more likely it is that the wall will be wet from the inside. And this is already creating Not favorable conditions for accommodation. By insulating a house, we can shift the dew point, since this changes the temperature of the wall itself.

Where will the dew point be?

There can be three options for wall construction: without insulation, with external and internal cladding. Let's consider where the dew point might be in each of these cases?

1. The design is without insulation, then the dew point is located:

• inside the wall closer to the outer surface;
• inside the wall it is shifted to the inner surface;
• on the inner surface - indoors the wall will remain wet throughout the winter period.

2. Available external insulation, then the dew point is:

• inside the insulation - this indicates that the calculation of the dew point and the thickness of the insulation was carried out correctly, and the wall in the room will be dry;
• any of the three cases described in paragraph 1 - the reason is the incorrect choice of insulation and its characteristics.

3. The internal lining is made, then the dew point will be:

• inside the wall closer to the insulation;
• on the inner surface of the wall under the cladding;
• in the insulation itself.

From what has been discussed above, it becomes clear that the location of the dew point also depends on such characteristics of the fence as temperature and vapor permeability. Majority modern insulation materials practically does not allow steam to pass through, so external wall cladding is recommended.

If you choose internal insulation, then the following conditions must be met in order to:

• the wall was dry and warm;
• the insulation had good vapor permeability and small thickness;
• ventilation and heating functioned in the building.

Knowing possible areas of condensation formation, i.e. location of the dew point, for certain climatic zones it is possible to select a type and material of insulation that will not create conditions for damp walls inside the house.

There is an opinion that the house should be insulated from the outside, and the insulation in all respects must comply with GOST. Then the dew point will be inside the sheathing, that is, outside the house, and the interior walls will be dry in any season. That is why external insulation is more profitable than internal insulation.

How to remove dew point from a wall (video)

The concept of dew point (hereinafter referred to as TP) is used in the design of thermal protection of civil and industrial buildings, and is a convenient parameter in the calculations of air drying systems and pneumatic installations. The dew point of the ambient air is taken into account when applying anti-corrosion coatings to metal substrates.

When the substrate temperature is lower than the air temperature, condensed moisture is present on the substrate, which prevents the desired adhesion from being achieved. On the painted surface, defects such as peeling or bubbling of the paint layer are formed, which contribute to the occurrence of premature corrosion.

A correctly performed calculation of the dew point determines what the thermal insulation of a residential building should be, taking into account heat consumption, air humidity and the characteristics of air exchange within the premises. The dew point temperature serves as a kind of indicator of the degree of air humidity from inside the living space. The dew point temperature determines the comfort level of living in the house. The higher the dew point in frame house, the higher the humidity in the room.

The atmosphere in such a room for heart patients and asthmatics is extremely suffocating and unbearable. Incorrect determination of the dew point in the wall of a residential building leads to the deposition of condensation on the surface of the walls and ceiling of the room.

Wet walls provoke the formation of mold and the development of microorganisms that enter the human body along with the inhaled air. Condensed moisture in the materials of wet walls and ceilings freezes in winter, sharply increasing in volume and weakening the strength qualities of the building structure. The picture below shows damp wooden wall

with fungal manifestations due to improper thermal insulation.

Physics of steam condensation

• Water is present in the environment of our home in two states of aggregation:
• liquid – this is water for cooking and sanitary needs;

gaseous - steam over boiling water or as one of the fractions of exhaled air.

In addition to such obvious places, traces of moisture are necessarily present in the materials of the elements of the building's building structure: concrete or brick walls, ceilings, and the base of the floor. There are no ideally dry building materials in nature. In stable warm weather, the steam present in the air and the moisture in the walls of the home are in thermal equilibrium. In this case, the partial pressure of steam in the air from the street (outer side of the wall) and inside the house (inner side of the wall) is the same. This means that no movement of water vapor occurs through the wall. In frosty weather, the humidity of cold air is low, and the partial pressure of vapor in such air is low. In accordance with the laws of thermophysics of steam

high blood pressure

(living space) begins to diffuse through the wall material into the cold street, where the pressure is lower. All building materials from which the walls of houses are constructed have the property of vapor permeability. Even concrete or brick walls are capable of transmitting steam through their thickness, although concrete and brick have minimal vapor permeability. When passing through the dew point in the wall, the vapor turns into liquid

state of aggregation

• , forming condensation moisture.
• During the cold season, periodic freezing of condensate moisture in the wall occurs, followed by thawing. The cyclical nature of freezing has a destructive effect on the structure building material, reducing the period of trouble-free operation of the building.

The figure below schematically shows the transformation of vaporous moisture into a liquid state (blue color is used) when TR gets inside the wall of the home.

TR calculation methods

The question of what dew point is is answered in the Code of Rules SP 50.13330.2012, which regulates the issues of thermal protection of buildings. In paragraph B.24, the concept of TP is interpreted as the temperature at which condensation moisture begins to form in the air with specific parameters of temperature and relative humidity.

The value of TP is indicated in degrees C! It should be taken into account that the TP value can never exceed the actual air temperature parameter for which TP is determined. Only in the case of 100% relative humidity will the TR coincide with the air temperature.

In accordance with the definition of TP, the temperature of condensation moisture depends on the values ​​of two parameters:

• on air temperature;
• on the relative humidity of the surrounding air.

For example, for air masses with a humidity of 40% and a temperature of 10 °C, the TP indicator will be minus 2.9 °C. If the humidity of the same volume is within 80%, the temperature will already reach plus 6.7 °C. For 100% humidity, the values ​​of TP and air t are the same = 10.0 °C.

When arranging thermal protection, it is very important to find a place where there may be a dew point in order to prevent the formation of condensation moisture in a place undesirable for providing effective thermal protection.

It is almost impossible to visually determine the position of the TR as the place of initial condensation. For the dew point indicator, determination is carried out using several methods.

Calculation methodThe following formula is very convenient for calculating TP in the positive temperature range up to 60

°C: T P = b*f(T,Rh)/(a-f(T,Rh)

• , Where
• T R – the temperature at which condensation begins, that is, the dew point in the wall, insulation or ambient air;
• f(T,Rh) = a*T/(b+T) + ln(Rh);
• ln – natural logarithm;
• a=17.27;
• b=237.7;
• Т – air temperature in °C;

Rh – relative humidity, indicated in volume fractions (from 0.01 to 1.00).

This formula works with an error of ±0.4 degrees Celsius.

There are simpler formulas that work with an error within ±1.0 degrees. C, for example, T p ≈T – (1-RH)/0.05. This formula can be used to calculate the relative humidity indicator using the already known temperature TR:

Tabular method

Numerous special tables based on laboratory measurements indicate TP values ​​depending on relative air humidity and temperature. The dew point parameter is determined in quite detail by the table in the reference appendix R of the Code of Rules SP 23-101-2004 “Design of thermal protection of buildings”. In Fig. Below is a similar dew point table that fully complies with the parameters from GOST and SP.

Table for determining dew point

Using household psychrometers

Psychrometers, or more precisely, psychrometric hygrometers, are designed to measure air temperature and relative humidity. A modern hygrometer can be used as a device for determining dew point, since an image of a psychrometric table is printed on its body.

Using the readings of both thermometers of the device, the TP is determined from the table. The figure below shows models of modern household psychrometers equipped with psychrometric tables that help determine the dew point.

Portable electronic thermohygrometers

The dew point in construction during thermal inspection of premises is determined using portable thermohygrometers with displays equipped with an indication of the values ​​of the ambient air temperature, its humidity and the TP parameter.

Thermal imager readings

There is no need to calculate TP if you use certain models of thermal imagers for construction purposes that have the function of calculating TP and display surfaces with temperatures below TP during thermal imaging. Given the given air parameters, it is possible to process thermal imaging data on a computer and show on thermograms all areas that risk falling into the condensation zone when insulating a wall or ceiling.

Housing options

The TP parameter is a kind of temperature boundary at which internal heat and external cold meet. In wall enclosing structures, warm air that diffuses from a heated room into a frosty street during the cold winter months is supercooled.

The vapor phase of water turns into a wet state, depositing on any surface that has a temperature below TP. The cause of condensation is not only the wall material (, brick or aerated concrete), but also the method of arranging the thermal protection of the building, which determines in which direction the thermal protection is shifted.

The location of the TR depends on the following factors:

• indoor and outdoor humidity indicators;
• indoor and outdoor air temperature indicators;
• thickness of the wall and insulating layer;
• places where insulating material is placed.

Depending on these factors, TP can be located not only on the surface of the wall, but also in the thickness of the wall or insulating material.

Options for the location of the TR in the “wall plus insulation” system provide for the placement of the insulation inside the room or on the outside of the enclosing wall (see figure below).

Wall without insulation

The location of the TR is within the thickness of the wall and can shift towards the street or room depending on changing temperature and humidity parameters. In any case, is the dew point in aerated concrete or brick wall

, condensation forms relatively far from the inner surface.

• Condensation moisture accumulates in the wall material and freezes in severe frosts. As temperatures warm, moisture thaws and evaporates out into the atmosphere.
• There are three possible options for placing the TR in the wall:
• the TP indicator found by calculation or tabular method fell between the geometric center of the wall thickness and the outer surface - the inner wall remained dry;

TP falls between the geometric center of the wall and the inner surface of the room - the walls of the room may get wet during a sharp cold snap;

The TR exactly hit the coordinate of the inner surface - the wall will be damp all winter. Heat loss with an uninsulated wall reaches 80%. The negative aspect of the occurrence of TR in a wall is the gradual destruction of the wall structure. Walls made of brick, aerated concrete, expanded clay blocks, etc., which are homogeneous in their design, have a TR inside the thickness of the material in winter. Repeated freeze/thaw cycles worsen the strength properties of building materials and reduce the strength of the entire wall structure. Therefore the walls

monolithic design

homogeneous composition must be insulated with heat-insulating materials.

• Insulation from the inside of the room
• The following options are possible for the location of the TR: if the dew point is in the insulation, then the insulation will be wet throughout the frosty period; and insulating polystyrene board. The wall finish will begin to get wet, which will cause the formation of damp spots and mold;
• the wall material is in the subzero temperature zone and is exposed to negative impacts temperature changes.

Insulation from the outside of the building

TP is brought into the outer heat-insulating layer. The possibility of condensation forming in the room is excluded, the walls will be dry.

Video: dew point in the wall

Theory and practice show that it is preferable to equip the thermal protection of a building from its outside. Then there is a greater chance that the TR will be in an area that does not allow moisture condensation inside the room.

Number of wall layers: 1 layer 2 layers 3 layers 4 layers 5 layers

1st layer

1st layer material:

Thickness of 1st layer: mm

3rd layer

3rd layer material: CONCRETE AND MORTAR Reinforced concrete Concrete on gravel or crushed stone natural stone Dense silicate concrete Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1400 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1200 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1000 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=500 Expanded clay concrete on quartz sand with porous P=1200 Expanded clay concrete on quartz sand with porous P=1000 Expanded clay concrete on quartz sand with porous P=800 Perlite concrete P=1200 Perlite concrete P=1000 Perlite concrete P=800 Perlite concrete P=600 Agloporite concrete and concretes on fuel slag P=1800 Agloporite concrete and concrete on fuel slag P=1600 Agloporite concrete and concrete on fuel slag P=1400 Agloporite concrete and concrete on fuel slag P=1200 Agloporite concrete and concrete on fuel slag P=1000 Concrete on ash gravel P= 1400 Concrete on ash gravel P=1200 Concrete on ash gravel P=1000 Polystyrene concrete P=600 Polystyrene concrete P=500 Gas and foam concrete. gas and foam silicate P=1000 Gas and foam concrete. gas and foam silicate P=900 Gas and foam concrete. gas and foam silicate P=800 Gas and foam concrete. gas and foam silicate P=700 Gas and foam concrete. gas and foam silicate P=600 Gas and foam concrete. gas and foam silicate P=500 Gas and foam concrete. gas and foam silicate P=400 Gas and foam concrete. gas and foam silicate P=300 Gas and foam ash concrete P=1200 Gas and foam ash concrete P=100 Gas and foam ash concrete P=800 Cement-sand mortar Complex (sand, lime, cement) mortar Lime-sand mortar Cement-slag mortar P =1400 Cement-slag mortar P=1200 Cement-perlite mortar P=1000 Cement-perlite mortar P=800 Gypsum perlite mortar Porous gypsum perlite mortar P=500 Porous gypsum perlite mortar P=400 Gypsum slabs P=1200 Gypsum slabs P=1000 Sheets gypsum cladding (dry plaster) Clay ordinary brick Sand-lime brick P=2000 Sand-lime brick P=1900 Sand-lime brick P=1800 Sand-lime brick P=1700 Sand-lime brick P=1600 Ceramic brick P=1600 Ceramic brick P=1400 Ceramic stone P=1700 Thickened silicate brick P=1600 Thickened silicate brick P=1400 Silicate stone P=1400 Silicate stone P=1300 Granite. gneiss and basalt Marble Limestone P=2000 Limestone P=1800 Limestone P=1600 Limestone P=1400 Tuff P=2000 Tuff P=1800 Tuff P=1600 Tuff P=1400 Tuff P=1200 Tuff P=1000 WOOD AND PRODUCTS FROM IT Pine and spruce across the grain Pine and spruce along the grain Oak along the grain Oak along the grain Glued plywood Facing cardboard Multilayer construction cardboard Wood fiber boards. and wood chips, wood fibers. P=1000 Wood fiber boards. and wood chips, wood fibers. P=800 Wood fiber boards. and wood chips, wood fibers. P=400 Wood fiber boards. and wood chips, wood fibers. P=200 Fiberboard and wood concrete slabs on Portland cement P=800 Fiberboard and wood concrete slabs on Portland cement P=600 Fiberboard slabs and wood concrete on Portland cement P=400 Fiberboard and wood concrete slabs on Portland cement P=300 Fiber thermal insulation slabs made from artificial fur waste P=175 Plates fibrous thermal insulation from artificial fur waste P=150 Fiber thermal insulation slabs from artificial fur waste P=125 Flax insulating slabs Peat thermal insulating slabs P=300 Peat thermal insulating slabs P=200 Tow THERMAL INSULATION MATERIALS Mineral wool mats pierced P=125 Mineral mats wool pierced P=100 Mats mineral wool pierced P=75 Mineral wool mats P=50 Mineral wool slabs on a synthetic binder P=250 Mineral wool slabs on a synthetic binder P=200 Mineral wool slabs on a synthetic binder P=175 Mineral wool slabs on a synthetic binder P=125 Mineral wool slabs on a synthetic binder P= 75 Polystyrene foam slabs P=50 Polystyrene foam slabs P=35 Polystyrene foam slabs P=25 Polystyrene foam slabs P=15 Polyurethane foam P=80 Polyurethane foam P=60 Polyurethane foam P=40 Resol-phenol-formaldehyde foam slabs P=100 Resol-phenol-formaldehyde slabs polystyrene foam P=75 Plates made of resol-phenol-formaldehyde polystyrene foam P=50 Plates made of resol-phenol-formaldehyde foam P=40 Polystyrene concrete thermal insulation slabs P=300 Polystyrene concrete thermal insulating slabs P=260 Polystyrene concrete thermal insulating slabs P=230 Expanded clay gravel P=800 Expanded clay gravel P=600 Expanded clay gravel P=4 00 Expanded clay gravel P=300 Gravel expanded clay P=200 Crushed stone and sand from expanded perlite P=600 Crushed stone and sand from expanded perlite P=400 Crushed stone and sand from expanded perlite P=200 Sand for construction work Foam glass and gas glass P=200 Foam glass and gas glass P=180 Foam glass and gas glass P=160 ROOFING, WATERPROOFING, FACING MATERIALS Flat asbestos-cement sheets P=1800 Flat asbestos-cement sheets P=1600 Petroleum construction and roofing bitumens P=1400 Petroleum bitumens for construction and roofing P =1200 Petroleum construction and roofing bitumens P=1000 Asphalt concrete Products made from expanded perlite on a bitumen binder P=400 Products made from expanded perlite on a bitumen binder P=300 Ruberoid. glassine roofing felt Multilayer polyvinyl chloride linoleum P=1800 Multilayer polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1800 Fabric backed polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1400 METALS AND GLASS Reinforcing rod steel Cast iron Aluminum Copper Window glass

3rd layer thickness: mm

5th layer

5th layer material: CONCRETE AND SOLUTIONS Reinforced concrete Concrete on gravel or crushed stone from natural stone Dense silicate concrete Expanded clay concrete concrete on expanded clay. sand and expanded clay foam concrete P=1800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1400 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1200 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1000 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=500 Expanded clay concrete on quartz sand with porous P=1200 Expanded clay concrete on quartz sand with porous P=1000 Expanded clay concrete on quartz sand with porous P=800 Perlite concrete P=1200 Perlite concrete P=1000 Perlite concrete P=800 Perlite concrete P=600 Agloporite concrete and concretes on fuel slag P=1800 Agloporite concrete and concrete on fuel slag P=1600 Agloporite concrete and concrete on fuel slag P=1400 Agloporite concrete and concrete on fuel slag P=1200 Agloporite concrete and concrete on fuel slag P=1000 Concrete on ash gravel P= 1400 Concrete on ash gravel P=1200 Concrete on ash gravel P=1000 Polystyrene concrete P=600 Polystyrene concrete P=500 Gas and foam concrete. gas and foam silicate P=1000 Gas and foam concrete. gas and foam silicate P=900 Gas and foam concrete. gas and foam silicate P=800 Gas and foam concrete. gas and foam silicate P=700 Gas and foam concrete. gas and foam silicate P=600 Gas and foam concrete. gas and foam silicate P=500 Gas and foam concrete. gas and foam silicate P=400 Gas and foam concrete. gas and foam silicate P=300 Gas and foam ash concrete P=1200 Gas and foam ash concrete P=100 Gas and foam ash concrete P=800 Cement-sand mortar Complex (sand, lime, cement) mortar Lime-sand mortar Cement-slag mortar P =1400 Cement-slag mortar P=1200 Cement-perlite mortar P=1000 Cement-perlite mortar P=800 Gypsum perlite mortar Porous gypsum perlite mortar P=500 Porous gypsum perlite mortar P=400 Gypsum slabs P=1200 Gypsum slabs P=1000 Sheets gypsum cladding (dry plaster) Clay ordinary brick Sand-lime brick P=2000 Sand-lime brick P=1900 Sand-lime brick P=1800 Sand-lime brick P=1700 Sand-lime brick P=1600 Ceramic brick P=1600 Ceramic brick P=1400 Ceramic stone P=1700 Bricks silicate thickened P=1600 Silicate brick thickened P=1400 Silicate stone P=1400 Silicate stone P=1300 Granite. gneiss and basalt Marble Limestone P=2000 Limestone P=1800 Limestone P=1600 Limestone P=1400 Tuff P=2000 Tuff P=1800 Tuff P=1600 Tuff P=1400 Tuff P=1200 Tuff P=1000 WOOD AND PRODUCTS FROM IT Pine and spruce across the grain Pine and spruce along the grain Oak along the grain Oak along the grain Glued plywood Facing cardboard Multilayer construction cardboard Wood fiber boards. and wood chips, wood fibers. P=1000 Wood fiber boards. and wood chips, wood fibers. P=800 Wood fiber boards. and wood chips, wood fibers. P=400 Wood fiber boards. and wood chips, wood fibers. P=200 Fiberboard and wood concrete slabs on Portland cement P=800 Fiberboard and wood concrete slabs on Portland cement P=600 Fiberboard slabs and wood concrete on Portland cement P=400 Fiberboard and wood concrete slabs on Portland cement P=300 Fiber thermal insulation slabs made from artificial fur waste P=175 Plates fibrous thermal insulation from artificial fur waste P=150 Fiber thermal insulation slabs from artificial fur waste P=125 Flax insulating slabs Peat thermal insulating slabs P=300 Peat thermal insulating slabs P=200 Tow THERMAL INSULATION MATERIALS Mineral wool mats pierced P=125 Mineral mats wool pierced P=100 Mats mineral wool pierced P=75 Mineral wool mats P=50 Mineral wool slabs on a synthetic binder P=250 Mineral wool slabs on a synthetic binder P=200 Mineral wool slabs on a synthetic binder P=175 Mineral wool slabs on a synthetic binder P=125 Mineral wool slabs on a synthetic binder P= 75 Polystyrene foam slabs P=50 Polystyrene foam slabs P=35 Polystyrene foam slabs P=25 Polystyrene foam slabs P=15 Polyurethane foam P=80 Polyurethane foam P=60 Polyurethane foam P=40 Resol-phenol-formaldehyde foam slabs P=100 Resol-phenol-formaldehyde slabs polystyrene foam P=75 Plates made of resol-phenol-formaldehyde polystyrene foam P=50 Plates made of resol-phenol-formaldehyde foam P=40 Polystyrene concrete thermal insulation slabs P=300 Polystyrene concrete thermal insulating slabs P=260 Polystyrene concrete thermal insulating slabs P=230 Expanded clay gravel P=800 Expanded clay gravel P=600 Expanded clay gravel P=4 00 Expanded clay gravel P=300 Gravel expanded clay P=200 Crushed stone and sand from expanded perlite P=600 Crushed stone and sand from expanded perlite P=400 Crushed stone and sand from expanded perlite P=200 Sand for construction work Foam glass and gas glass P=200 Foam glass and gas glass P=180 Foam glass and gas glass P=160 ROOFING, WATERPROOFING, FACING MATERIALS Flat asbestos-cement sheets P=1800 Flat asbestos-cement sheets P=1600 Petroleum construction and roofing bitumens P=1400 Petroleum construction and roofing bitumens P=1200 Petroleum construction and roofing bitumens P=1000 Ac False concrete Products made from expanded perlite on a bitumen binder P=400 Products made of expanded perlite on a bitumen binder P=300 Ruberoid. glassine roofing felt Multilayer polyvinyl chloride linoleum P=1800 Multilayer polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1800 Fabric backed polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1400 METALS AND GLASS Reinforcing rod steel Cast iron Aluminum Copper Window glass

Thickness of the 5th layer: mm

2nd layer

2nd layer material: CONCRETE AND SOLUTIONS Reinforced concrete Concrete on gravel or crushed stone from natural stone Dense silicate concrete Expanded clay concrete concrete on expanded clay. sand and expanded clay foam concrete P=1800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1400 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1200 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1000 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=500 Expanded clay concrete on quartz sand with porous P=1200 Expanded clay concrete on quartz sand with porous P=1000 Expanded clay concrete on quartz sand with porous P=800 Perlite concrete P=1200 Perlite concrete P=1000 Perlite concrete P=800 Perlite concrete P=600 Agloporite concrete and concretes on fuel slag P=1800 Agloporite concrete and concrete on fuel slag P=1600 Agloporite concrete and concrete on fuel slag P=1400 Agloporite concrete and concrete on fuel slag P=1200 Agloporite concrete and concrete on fuel slag P=1000 Concrete on ash gravel P= 1400 Concrete on ash gravel P=1200 Concrete on ash gravel P=1000 Polystyrene concrete P=600 Polystyrene concrete P=500 Gas and foam concrete. gas and foam silicate P=1000 Gas and foam concrete. gas and foam silicate P=900 Gas and foam concrete. gas and foam silicate P=800 Gas and foam concrete. gas and foam silicate P=700 Gas and foam concrete. gas and foam silicate P=600 Gas and foam concrete. gas and foam silicate P=500 Gas and foam concrete. gas and foam silicate P=400 Gas and foam concrete. gas and foam silicate P=300 Gas and foam ash concrete P=1200 Gas and foam ash concrete P=100 Gas and foam ash concrete P=800 Cement-sand mortar Complex (sand, lime, cement) mortar Lime-sand mortar Cement-slag mortar P =1400 Cement-slag mortar P=1200 Cement-perlite mortar P=1000 Cement-perlite mortar P=800 Gypsum perlite mortar Porous gypsum perlite mortar P=500 Porous gypsum perlite mortar P=400 Gypsum slabs P=1200 Gypsum slabs P=1000 Sheets gypsum cladding (dry plaster) Clay ordinary brick Sand-lime brick P=2000 Sand-lime brick P=1900 Sand-lime brick P=1800 Sand-lime brick P=1700 Sand-lime brick P=1600 Ceramic brick P=1600 Ceramic brick P=1400 Ceramic stone P=1700 Bricks silicate thickened P=1600 Silicate brick thickened P=1400 Silicate stone P=1400 Silicate stone P=1300 Granite. gneiss and basalt Marble Limestone P=2000 Limestone P=1800 Limestone P=1600 Limestone P=1400 Tuff P=2000 Tuff P=1800 Tuff P=1600 Tuff P=1400 Tuff P=1200 Tuff P=1000 WOOD AND PRODUCTS FROM IT Pine and spruce across the grain Pine and spruce along the grain Oak along the grain Oak along the grain Glued plywood Facing cardboard Multilayer construction cardboard Wood fiber boards. and wood chips, wood fibers. P=1000 Wood fiber boards. and wood chips, wood fibers. P=800 Wood fiber boards. and wood chips, wood fibers. P=400 Wood fiber boards. and wood chips, wood fibers. P=200 Fiberboard and wood concrete slabs on Portland cement P=800 Fiberboard and wood concrete slabs on Portland cement P=600 Fiberboard slabs and wood concrete on Portland cement P=400 Fiberboard and wood concrete slabs on Portland cement P=300 Fiber thermal insulation slabs made from artificial fur waste P=175 Plates fibrous thermal insulation from artificial fur waste P=150 Fiber thermal insulation slabs from artificial fur waste P=125 Flax insulating slabs Peat thermal insulating slabs P=300 Peat thermal insulating slabs P=200 Tow THERMAL INSULATION MATERIALS Mineral wool mats pierced P=125 Mineral mats wool pierced P=100 Mats mineral wool pierced P=75 Mineral wool mats P=50 Mineral wool slabs on a synthetic binder P=250 Mineral wool slabs on a synthetic binder P=200 Mineral wool slabs on a synthetic binder P=175 Mineral wool slabs on a synthetic binder P=125 Mineral wool slabs on a synthetic binder P= 75 Polystyrene foam slabs P=50 Polystyrene foam slabs P=35 Polystyrene foam slabs P=25 Polystyrene foam slabs P=15 Polyurethane foam P=80 Polyurethane foam P=60 Polyurethane foam P=40 Resol-phenol-formaldehyde foam slabs P=100 Resol-phenol-formaldehyde slabs polystyrene foam P=75 Plates made of resol-phenol-formaldehyde polystyrene foam P=50 Plates made of resol-phenol-formaldehyde foam P=40 Polystyrene concrete thermal insulation slabs P=300 Polystyrene concrete thermal insulating slabs P=260 Polystyrene concrete thermal insulating slabs P=230 Expanded clay gravel P=800 Expanded clay gravel P=600 Expanded clay gravel P=4 00 Expanded clay gravel P=300 Gravel expanded clay P=200 Crushed stone and sand from expanded perlite P=600 Crushed stone and sand from expanded perlite P=400 Crushed stone and sand from expanded perlite P=200 Sand for construction work Foam glass and gas glass P=200 Foam glass and gas glass P=180 Foam glass and gas glass P=160 ROOFING, WATERPROOFING, FACING MATERIALS Flat asbestos-cement sheets P=1800 Flat asbestos-cement sheets P=1600 Petroleum construction and roofing bitumens P=1400 Petroleum construction and roofing bitumens P=1200 Petroleum construction and roofing bitumens P=1000 Ac False concrete Products made from expanded perlite on a bitumen binder P=400 Products made of expanded perlite on a bitumen binder P=300 Ruberoid. glassine roofing felt Multilayer polyvinyl chloride linoleum P=1800 Multilayer polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1800 Fabric backed polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1400 METALS AND GLASS Reinforcing rod steel Cast iron Aluminum Copper Window glass

Thickness of 2nd layer: mm

4th layer

4th layer material: CONCRETE AND SOLUTIONS Reinforced concrete Concrete on gravel or crushed stone from natural stone Dense silicate concrete Expanded clay concrete concrete on expanded clay. sand and expanded clay foam concrete P=1800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1400 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1200 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=1000 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=800 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=600 Expanded clay concrete on expanded clay. sand and expanded clay foam concrete P=500 Expanded clay concrete on quartz sand with porous P=1200 Expanded clay concrete on quartz sand with porous P=1000 Expanded clay concrete on quartz sand with porous P=800 Perlite concrete P=1200 Perlite concrete P=1000 Perlite concrete P=800 Perlite concrete P=600 Agloporite concrete and concretes on fuel slag P=1800 Agloporite concrete and concrete on fuel slag P=1600 Agloporite concrete and concrete on fuel slag P=1400 Agloporite concrete and concrete on fuel slag P=1200 Agloporite concrete and concrete on fuel slag P=1000 Concrete on ash gravel P= 1400 Concrete on ash gravel P=1200 Concrete on ash gravel P=1000 Polystyrene concrete P=600 Polystyrene concrete P=500 Gas and foam concrete. gas and foam silicate P=1000 Gas and foam concrete. gas and foam silicate P=900 Gas and foam concrete. gas and foam silicate P=800 Gas and foam concrete. gas and foam silicate P=700 Gas and foam concrete. gas and foam silicate P=600 Gas and foam concrete. gas and foam silicate P=500 Gas and foam concrete. gas and foam silicate P=400 Gas and foam concrete. gas and foam silicate P=300 Gas and foam ash concrete P=1200 Gas and foam ash concrete P=100 Gas and foam ash concrete P=800 Cement-sand mortar Complex (sand, lime, cement) mortar Lime-sand mortar Cement-slag mortar P =1400 Cement-slag mortar P=1200 Cement-perlite mortar P=1000 Cement-perlite mortar P=800 Gypsum perlite mortar Porous gypsum perlite mortar P=500 Porous gypsum perlite mortar P=400 Gypsum slabs P=1200 Gypsum slabs P=1000 Sheets gypsum cladding (dry plaster) Clay ordinary brick Sand-lime brick P=2000 Sand-lime brick P=1900 Sand-lime brick P=1800 Sand-lime brick P=1700 Sand-lime brick P=1600 Ceramic brick P=1600 Ceramic brick P=1400 Ceramic stone P=1700 Bricks silicate thickened P=1600 Silicate brick thickened P=1400 Silicate stone P=1400 Silicate stone P=1300 Granite. gneiss and basalt Marble Limestone P=2000 Limestone P=1800 Limestone P=1600 Limestone P=1400 Tuff P=2000 Tuff P=1800 Tuff P=1600 Tuff P=1400 Tuff P=1200 Tuff P=1000 WOOD AND PRODUCTS FROM IT Pine and spruce across the grain Pine and spruce along the grain Oak along the grain Oak along the grain Glued plywood Facing cardboard Multilayer construction cardboard Wood fiber boards. and wood chips, wood fibers. P=1000 Wood fiber boards. and wood chips, wood fibers. P=800 Wood fiber boards. and wood chips, wood fibers. P=400 Wood fiber boards. and wood chips, wood fibers. P=200 Fiberboard and wood concrete slabs on Portland cement P=800 Fiberboard and wood concrete slabs on Portland cement P=600 Fiberboard slabs and wood concrete on Portland cement P=400 Fiberboard and wood concrete slabs on Portland cement P=300 Fiber thermal insulation slabs made from artificial fur waste P=175 Plates fibrous thermal insulation from artificial fur waste P=150 Fiber thermal insulation slabs from artificial fur waste P=125 Flax insulating slabs Peat thermal insulating slabs P=300 Peat thermal insulating slabs P=200 Tow THERMAL INSULATION MATERIALS Mineral wool mats pierced P=125 Mineral mats wool pierced P=100 Mats mineral wool pierced P=75 Mineral wool mats P=50 Mineral wool slabs on a synthetic binder P=250 Mineral wool slabs on a synthetic binder P=200 Mineral wool slabs on a synthetic binder P=175 Mineral wool slabs on a synthetic binder P=125 Mineral wool slabs on a synthetic binder P= 75 Polystyrene foam slabs P=50 Polystyrene foam slabs P=35 Polystyrene foam slabs P=25 Polystyrene foam slabs P=15 Polyurethane foam P=80 Polyurethane foam P=60 Polyurethane foam P=40 Resol-phenol-formaldehyde foam slabs P=100 Resol-phenol-formaldehyde slabs polystyrene foam P=75 Plates made of resol-phenol-formaldehyde polystyrene foam P=50 Plates made of resol-phenol-formaldehyde foam P=40 Polystyrene concrete thermal insulation slabs P=300 Polystyrene concrete thermal insulating slabs P=260 Polystyrene concrete thermal insulating slabs P=230 Expanded clay gravel P=800 Expanded clay gravel P=600 Expanded clay gravel P=4 00 Expanded clay gravel P=300 Gravel expanded clay P=200 Crushed stone and sand from expanded perlite P=600 Crushed stone and sand from expanded perlite P=400 Crushed stone and sand from expanded perlite P=200 Sand for construction work Foam glass and gas glass P=200 Foam glass and gas glass P=180 Foam glass and gas glass P=160 ROOFING, WATERPROOFING, FACING MATERIALS Flat asbestos-cement sheets P=1800 Flat asbestos-cement sheets P=1600 Petroleum construction and roofing bitumens P=1400 Petroleum construction and roofing bitumens P=1200 Petroleum construction and roofing bitumens P=1000 Ac False concrete Products made from expanded perlite on a bitumen binder P=400 Products made of expanded perlite on a bitumen binder P=300 Ruberoid. glassine roofing felt Multilayer polyvinyl chloride linoleum P=1800 Multilayer polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1800 Fabric backed polyvinyl chloride linoleum P=1600 Fabric backed polyvinyl chloride linoleum P=1400 METALS AND GLASS Reinforcing rod steel Cast iron Aluminum Copper Window glass

Thickness of 4th layer: mm

Why do windows, doors, walls sweat? Why do things that are brought from a cold room into a warm room become covered with condensation? Why do pipes get wet? cold water? - there is only one answer, the surface temperature of the object is lower dew point temperature.

Dew point (Dew point temperature TP) is the temperature at which dew begins to form, i.e. the temperature to which the air must be cooled in order for the relative humidity to reach 100%

From a school physics course we know that air humidity (water content in the air) is determined by two parameters:

Absolute humidity;
Relative humidity.

WITH absolute humidity(f ) everything is clear - this is the amount of water, in grams, contained in one cubic meter of air, the unit of measurement is grams per cubic meter, g/m3.

f = m/V

V - volume of moist air;

m - the mass of water vapor contained in this volume.

Relative humidity(RH ) is the amount of water contained in the air relative to the maximum possible amount of water at a given temperature and pressure, the unit of measurement is percent, % .

And with increase in temperature, maximum possible amount of water contained in the air - increases.

Accordingly, when decreasing temperature – decreases.

With a further decrease in temperature " extra» the water will begin to condense in the form of dew drops- That's what it is Dew point.

A few facts about dew point.

• The dew point temperature cannot be higher than the current temperature.
• The higher the dew point temperature, the more moisture there is in the air
• High dew point temperatures occur in the tropics, low in deserts and polar regions.
• Relative humidity (RH) of about 100% leads to dew, frost (frozen dew), and fog.
• Relative humidity (RH) reaches 100% during the rainy season.
• High dew points usually occur ahead of cold temperature fronts.

How to determine and calculate the dew point?

The answer is obvious -

1. There are special tables to determine the dew point,

where the columns indicate Relative humidity in % , in lines – ambient air temperature in °C, in the cells at the intersection - the dew point temperature for the selected humidity and temperature.

For example, a relative humidity of 60% is selected, room temperature 21 °C at the intersection we see dew point value 12.9 °C.

Accordingly, under these conditions, moisture condensation will occur on cold surfaces (for example, window glass) With surface temperature lower than 12.9 °C.

On specialized sites there are more detailed tables for determining the dew point, but for “home use” the table below is quite sufficient; it can be saved, printed and used if necessary.

2. When calculating the dew point temperature, we use formulas 1.1 and 1.2.

Formula for approximate calculation of dew point in degrees Celsius (only for positive temperatures):

Tp = (b f (T, RH)) / (a ​​- f (T, RH)) , (1.1 )

f (T, RH) = a T / (b + T) + ln (RH / 100) , (1.2 )

Tr – dew point temperature, °C;

a = 17.27;

b = 237,7;

T – room temperature, °C;

RH – relative humidity, %;

Ln– natural logarithm.

Let's calculate dew point for the same temperature and humidity values.

T= 21 °C;

RH = 60 %.

First let's calculate the function f(T, RH)

f (T, RH) = a T / (b + T) + ln (RH / 100),

f (T, RH) = 17.27 * 21 / (237.7+21) + ln (60 / 100) =

= 1,401894 + (-0,51083) = 0,891068

Then dew point temperature

Tp = (b f (T, RH)) / (a ​​- f (T, RH)),

Tp = (237,7 * 0,891068) / (17,27 - 0,891068) =

= 211,807 / 16,37893 = 12.93167 °C

So, our calculation result Tr = 12.93167 °C .

3. It is much easier to calculate the dew point using “ Dew point calculator" on our website.

Fill in the values:

Air temperature indoors, ° WITH . - 21 ;

Relative humidity, % . – 60 .

As we see, the dew point value for all three methods is the same:

Tr= 12.9 °C;

Tr= 12.93167 °C;

Tr= 12.93 °C.

The only difference is the number of decimal places.

Fair questions arise - why do we need this dew point, why do we spend so much time determining or calculating what practical use has a dew point?

In places where moisture constantly accumulates, favorable conditions are created for the development of mold and fungal spores, which has a very negative impact on health located nearby of people.

Knowing the dew point, we can prevent condensation from forming on the surfaces of our premises.