How to make a calculation of a warm floor using the example of a water system. How to calculate a water heated floor

Underfloor heating is becoming more and more commonplace in our homes. They heat the floor with water heating, laying pipes in a screed, or electricity - various heating elements that turn electricity into heat. It is far from always possible to make a water heated floor - in old apartments it is unrealistic to get permission for it. It is easier with electric heating - you can find an option even for old floors, which gives the minimum load. But in order for the house to be warm, it is imperative to pre-calculate the electric floor heating. Then the cost of the arrangement will be optimal, and the power is sufficient even for the coldest periods.

Calculation methods

First of all, you need to decide whether you will have a warm floor as the main heating (without radiators and other heat sources) or additional (to increase comfort). Depending on this, the calculation of the electric floor heating changes. If floor heating is only additional heating, the only requirement is that there should be enough power to heat the floor to a comfortable 28.5-29°C. There are no other requirements. In this scenario, boldly use the average numbers, which are determined empirically (in the table below). When using floor heating as the main heating, the approach is different: there must be enough heat to compensate for heat loss. Here everything is somewhat more complicated - calculations are needed.

Calculation of electric underfloor heating by heat loss

There are two ways to make an electric floor heating calculation. The first one is just a calculation. When using this technique, the heat loss of the room is first determined. This takes into account the region in which the building is located, the material and thickness of the walls, the thickness and type of insulation, the size of the windows and the type of glazing, the presence and area of ​​the walls facing the street, the orientation of the room (south, north, etc.). All these factors affect the amount of heat that leaves the room and that will have to be replenished.

Heat loss for each type building material can be found in the specialized literature, there are separate methods. Such a calculation is a chore, but it allows you to get accurate data. This is in case you want to count yourself. If not, you can order a heat engineering calculation from specialists. And, if the areas for floor heating are planned to be large, it is better to order anyway. Sometimes, independently determined heat losses are several times higher than those that will be given to you by specialists. And extra power is a waste of money.

The resulting figure will be the power of the electric underfloor heating, which is necessary to compensate for the heat loss of this room. The whole calculation of the electric underfloor heating is to pick up heating elements in such quantity and such power that they give out the required amount of heat in total (it is possible with a small margin). If these are heating cables, it will be necessary to develop a laying scheme so that all the required cable footage is placed on a given area. If you decide to use a film underfloor heating, you need to look for a film of the required power. In any case, keep in mind that in order not to feel cold and hot places of heating with your feet, the distance between adjacent heating elements should not be more than 30 cm. And for normal heat redistribution (not stripes) minimum height screeds should be - 3 cm, preferably about 5 cm.

Note! Electric underfloor heating is laid only on the area that is not occupied by furniture and large household appliances. This is due to the fact that for the most part the heating elements of the warm floor do not tolerate overheating (except for the self-regulating heating cable). Therefore, the calculation of an electric underfloor heating begins with the location of furniture and appliances on the plan (on a scale). Having determined the area not occupied by the situation, you can proceed to the calculation. Another important point: if a warm floor is the main source of heat, then the heated surface should not be less than 70% of the total area of ​​​​the room.

Determining the required power depending on the purpose of the room

The second way is to count according to the average data. The amount of materials used in the construction of residential buildings is limited. This made it possible to derive the average figures for the required underfloor heating capacities for space heating. for various purposes. (see table).

When calculating an electric underfloor heating, the unoccupied area found is multiplied by the rate taken from the table. They get a figure that an electric underfloor heating can give out. In principle, this will also be the maximum power consumption required for underfloor heating.

For example, if 10 square meters are heated in a living room on the ground floor, then the heating element can produce / consume 140 W / m2 * 10 m2 = 1400 W. This is the power consumption per hour. Don't be afraid. In reality, such a flow can be only immediately after switching on and until the floor reaches the set temperature. During this period of time, the heaters operate continuously. Then the heating is turned on/off by the thermostat, which maintains the set temperature with an accuracy of 1°C. The amount of electricity consumed during this period depends on the weather (the colder, the more often it will turn on) and the degree of insulation of the floor and the room as a whole.

What can affect heat transfer

How well the floor heating will work is influenced not only by the power of the heating elements, but also by how well the whole “pie” is designed and made, how the materials are correctly selected.

Coating

First of all, the heat transfer is affected by the coating, which is laid on top of the heating elements. For example, if a resistive or self-regulating cable, mats from it or a rod infrared floor are used for heating, most often they are poured into the screed. In this case, special mixtures for underfloor heating are used. Another option is the standard cement-sand mortar add additives that increase the thermal conductivity of concrete. The second option is cheaper, but you will have to look for information about the necessary additives. But you can save.

Then ceramic tiles are laid on the screed - in the bathroom, corridor, in the kitchen. AT living rooms more often use laminate, linoleum, carpet.

No matter what kind of flooring you plan to purchase, you should only use materials that are designed for laying on underfloor heating. They have increased thermal conductivity, normally tolerate prolonged heating. So the increased price is justified, and the heating will be more efficient.

The most unfortunate choice of finishing coating for underfloor heating is carpet. Even a special one, it conducts heat worse than all others. In order to heat it up to an acceptable 28-29°C, it is necessary to raise the temperature of the heating elements by 4-5°C more than with other types of finishes.

The best choice - ceramic tile or porcelain stoneware. They have good thermal conductivity, but they also have a high heat capacity - a lot of time passes until they warm up. It is necessary to lay tiles and a warm floor on a special glue.

When using heating cables (any) or underfloor heating, the laying technology is the same. First, the screed is poured, the concrete gains strength over 28 days, then the tiles are laid. When using heating cable mats, the process changes, and significantly: the tiles can be laid directly on top of the mats on the required adhesive layer. The consumption of glue in this case is large (the minimum layer of tiles + glue is 3 cm), but much less time is required.

Film underfloor heating can be done without a screed. It is placed under the laminate. Only a special substrate (for underfloor heating) is spread over the film and laminate can be laid. Under linoleum or the same carpet, they make a rigid base - they lay sheets of plywood, or, and already they are laid on them top coat. Such an electric underfloor heating device - without a screed - is possible only if there is radiator heating. Everything fits quickly, but the heating is inefficient - high heat transfer cannot be achieved by any means.

thermal insulation

The better the thermal insulation of the floor under electric heaters, the less electricity is required to maintain normal temperature. If during construction the floor was already sufficiently insulated, it is possible not to lay the insulation. Although any system - you lay a cable or film floor - indicates the need to use a heat-insulating substrate. They are different in different systems but their presence is desirable. Then, making the calculation of the electric underfloor heating according to average statistics, you can take the required power along the lower edge or even a little lower. And this is money saved both during installation and during operation (less heat is spent on non-target heating).

A little bit about thermal insulation materials, which are recommended for use when installing a warm floor. The most optimal is extruded polystyrene foam (EPS). It has sufficient density and strength to withstand the pressure of the screed and everything that will be on it. The second option is sprayed thermal insulation. high density. The method is even better, but also more expensive. The density under the screed requires a high 60-80 kg / cubic meter, and such sprayed thermal insulation costs even more than XPS. True, it has the best characteristics for today (thermal conductivity is almost the same as that of air 0.2-0.3, depending on the manufacturer).

Often, when laying an electric underfloor heating, it is advised to use thermal insulation with a foil surface. This is argued by the fact that the foil reflects heat rays into the room. It works like this, but with an air gap between the heater and the foil (at least 3 cm). There is no warm floor in the cake and there cannot be any air gaps. So laying this material is just a waste of money and time. There is another argument against laying a layer of foil under a warm floor. The foil in the concrete crumbles to dust after a few weeks and becomes completely useless. They cannot even redistribute heat more evenly in this state.

Temperature controllers and sensors

The electric floor heating circuit assumes the presence of a thermostat and a temperature sensor. Their presence is not necessary - you can manually turn the heaters on and off. But only with these devices the system will work normally, long term, will provide the required level of comfort, it will be rational to use electricity, to avoid overheating. The presence or absence of a temperature controller with a sensor does not affect the calculation of an electric underfloor heating, but it affects the service life very much. As already mentioned, the vast majority of heating elements are afraid of overheating, and when it manual control very difficult to avoid. A couple of times you don’t have time to turn it off in time, the cables / film / mats will melt.

Today underfloor heating system is widely used not only as additional heating, but also the main one - without radiators on the wall. It creates a comfortable and more efficient heating rooms compared to conventional heating. Read about the advantages and connection of the Underfloor heating system in our article.

Mount a warm floor with your own hands most owners will be able to without calling specialists. You need to buy a box with everything you need called "warm floor" and a thermostat. How to lay it correctly I will tell in the next article.

On the floor areas occupied by them no heating cable, which will lead to its overheating and subsequent breakdown.

If the room is very small usable space , then it makes no sense to lay the heating cable.

If you plan to use electric underfloor heating as the only or the main source of space heating, keep in mind that if the heating cable is laid on less than 70% of the entire area, then the room will be cool.

Warm floor it is forbidden to mount under parquet due to the characteristics of this material.

Specific power used in calculations.

If you expect to use electric underfloor heating as the main or the only type of heating, then the specific power should be in the range from 160 to 180 watts per 1 square meter.

Specific output of additional heating should be in the range from 120 to 140 watts per 1 square meter. This type heating is used only in conjunction with the main source of heating (gas boiler or electric). Best Option use in apartments during the off-season at a time when it has not yet begun or has already ended heating season and it's still cold outside.

The required amount of heating power for different rooms You will find in the table.

All rooms in a house or apartment are used differently, so the requirements will be different.

It is clear that the power of the kitchen or corridor heating system will be less than for the bedroom.

All power values ​​​​are indicated with a small margin, because the thermostat is usually rarely set to maximum. And by making the power of the warm floor with a 20-25 percent margin, you exclude the possibility that the degree of heating will be insufficient. Agree that it is easier to reduce the adjustment than to experience discomfort from insufficient heat. In addition, there are many various factors that affect the efficiency of the underfloor heating system.
For example, if the room is located on the ground floor, then the power must be increased by 15 - 20 percent.

An example of calculating the electric floor heating.

To calculate, you need to use a fairly simple formula. We take from the table coefficient of specific power for a suitable type of room and type of heating, multiplied by the area of ​​\u200b\u200bthe room where you are going to install an electric underfloor heating.

For example, let's make a calculation for a room on the 2nd floor with a total area of ​​15 square meters.

1. Straightaway it is necessary to determine the usable area. For example, you have a bed measuring 2 by 2.20 m, the area occupied by it is 2x2.2 \u003d 4.4 square meters. meters. And there is also a closet, the area of ​​\u200b\u200bwhich is 1x1.1 \u003d 1.1 square meters. m. The useful area will be equal to 15-4.4-1.1 \u003d 9.5 square meters. m.
2. From the table we take the appropriate coefficient for additional heating of a room not on the first floor, which is equal to 120-130 W per meter.
3. We multiply these two numbers and we get 9.5x120 = 1140 watts.

So we need to buy an electric underfloor heating with a power of 1200 watts.

Before choosing one or another electric built-in heating system, it is necessary to calculate the warm floor. This will provide preliminary information on the costs of its arrangement. You can entrust the design of underfloor heating to professionals by contacting a construction company specializing in such work. In this case, you will not only calculate the costs, but will also be offered best option, taking into account your budget, wishes and features of the apartment.

To calculate the underfloor heating yourself, use online calculators. Many companies offering heating installation services place similar calculators on their websites. The underfloor heating calculation program makes it quite easy to make the necessary calculations if you follow the instructions given in it.

In addition, on the network you can find more than one example of an estimate for underfloor heating, indicating prices for materials and work. Using a similar sample, but substituting your numbers in the calculations, you can make calculations for your room.

Necessary data for underfloor heating calculations

When calculating underfloor heating, it is necessary to determine the size of the room where they will be equipped. But remember that only the area free from large items is considered - furniture, household appliances. Therefore, when planning equipment electric floors, it is necessary to decide in advance how the interior elements will be located in the room. It is not recommended to change their location after the installation of the system.

Before calculating a warm floor, select the desired type of heating. This indicator is of key importance. The capacity of the system, which is used as the main heat source, must be significantly greater than that of the floor for additional heating.

If the underfloor heating project assumes that the system will serve as a replacement for centralized heating, then the heated surface must be at least 70% of the total area.

If the room is densely crowded with furniture, then it will be impossible to comply with this condition. In this case, it makes no sense to install an electric floor, and you will have to look for another option for heating the room.

When calculating a warm floor as the main source of heat, it should be assumed that its specific power should be at least 150 W / m2. For additional heating, a power of 110-140 watts is enough. This floor will support comfortable temperature during the off-season when centralized heating not working yet.

A comfortable (additional) type of heating will also help out if the room is located on the ground floor, and under it there is cold cellar. The calculation of the power of the warm floor is made taking into account this factor. For dry rooms on the ground floor, such as a kitchen or corridor, you need to choose maximum power, i.e. 140 W.

Calculation for different types of premises

Each room has its own functional features and, accordingly, special requirements for the specific power of the heating system. Before calculating the power of a warm floor, select the type of room. Glazed loggias and balconies are the most demanding: for comfortable heating, it is required to lay down a power of at least 180 W / m2. For wet rooms bathroom type will need 140 W/m2. The same applies to all rooms, if there is an unheated space under them.

And in the calculation of the electric floor heating for bedrooms, corridors and living rooms, which are located on upper floors, the minimum power is laid - 120 W / m2.

After the heated area and the required power are calculated, you can choose the type that is most suitable for your purposes. electric heater: cable, warm mat, film or rod infrared floor.

Mounting Features various kinds warm floors and their price have the most significant impact on the final cost.

Thermal insulation for floors

To understand how to correctly calculate a warm floor, you need to know the following: calculations on sites are given for typical rooms in which thermal insulation is made and double glazing. Therefore, the calculation of the cost of a warm floor must necessarily include the cost of thermal insulation.

The use of insulating materials will not only reduce heat loss in rooms that have a cold foundation or earth underneath, but will also save energy in more protected rooms.

For some electric heating systems, such as infrared film and rod floors, the use of a special reflective substrate is a guarantee effective work. Consider this point before you calculate the electric floor heating.

Temperature controllers

The thermostat is one of important elements complete with electric floor. With its help, the system is powered from the network, as well as heating control. Using this device saves electrical energy. If you choose underfloor heating, how to calculate the cost of purchasing a thermostat? Before purchasing a particular model, decide which features you will use regularly. The choice is wide - from the simplest mechanical devices to intelligent systems that can effectively manage the heating of the house in the absence of the owners.

Any example of calculating a warm floor will give you approximate information about the cost of heating system equipment. To obtain a more accurate result, you need to take into account all the features of a particular room and the conditions in which it will function. this system. Only specialists can do this, so if you are interested in accurate data, seek the help of professionals.

Active positions in the installation of a solid system today are occupied by water heated floors. In view of their clear benefits, more and more developers are paying attention to this system. Before proceeding with the installation, you need to make a competent calculation of the warm floor. This material will be devoted to this.

A warm water floor is a system of pipes hidden under a screed, through which water of a certain temperature of about + 35 ° C circulates. Today, this is the most demanded technology for heating private houses. And this is no accident - thanks to the circulation of water inside the system, the heating is uniform and comfortable, unlike radiator distributors heat. Simplicity of design, independence from seasonal heating, temperature and pressure surges are another big plus of this technology. Such a system is heated mainly with the help of gas boiler. But without problems interacts with other types of boilers.

This design consists of polyethylene or metal-plastic pipes. It is these materials that are quite flexible and conduct heat well. A pump, a manifold and a thermostatic mixer are responsible for regulating the temperature in such a system.

Benefits of underfloor heating:

• compatible with many types floor covering- you can choose any coating you need without worrying that the heating system will damage it;
• saving heat - the system heats from below, thanks to which all the cold air rises, which allows you to heat the room without using other heat sources;
• seasonal options - in the cold season, the system acts as a heating structure, and in the summer it is able to cool the room.

However, there are some nuances that you need to familiarize yourself with before installing such a system:

• More expensive than a radiator system. When building a house with underfloor heating, get ready for increased spending, which will not really pay for itself, but at the same time will bring a lot of pleasant things in terms of heating.
• Not everywhere copes with warming up. In most cases, underfloor heating is used as the main heating, but there are rooms where additional device heating. To clarify this fact, and you need to do the calculation of the warm floor.
• Prohibited use in apartment buildings. But it concerns mainly Russia. In other countries, there are no such restrictions.

Based on all this, we can conclude - this technology more appropriate in the territory of a private house than an apartment. It is advisable to entrust the installation of this system to the masters, since there is a possibility of leaks that do not appear immediately. Poor assembly can cause a lot of trouble and cause serious damage to property.

Calculation of heat loss at home

Before calculating the warmest floor, you must first calculate the heat loss of your home. Heat loss is the amount of heat that a room loses per unit of time. To reduce heat loss, heating devices are used, for example, radiator heaters, heating pipes and underfloor heating. In addition, it is possible to reduce heat loss by installing double-glazed windows and insulating walls with various materials that can keep heat inside the room.

Calculation of heat loss is important parameter when designing a home. In this case, it is necessary to take into account:

• area of ​​the room;
• area of ​​all windows;
• ceiling height;
• the number of external walls;
• temperature with outer side premises;
• window type;
• thermal insulation of walls;
• the type of room above.

Basically, heat losses depend on the difference in temperatures outside and inside the room, as well as the degree of thermal insulation of windows, walls, partitions. For a more accurate calculation of heat loss, you can use one of the many online calculators. They are quite simple and clear to use, just enter the required values ​​and the calculation will be done automatically. In such calculators, it is possible to calculate heat loss through windows, ceilings, walls, floors. This will provide more detailed information on the basis of which the power of heating equipment should be calculated.

Detailed calculation of a water heated floor

When making calculations, please note that the maximum optimal temperature floor surface will be a value of 28 degrees. In case of exceeding given value discomfort may occur. In those places where the floor borders windows or doors and external walls, the temperature can be higher up to +35°C, and in bathrooms up to +33°C.

Pay attention also to the coating that you are going to use, as each coating has its own resistance to heat transfer. The recommended value should not exceed 0.15 M2K/W

When calculating underfloor heating, also pay attention to the fact that Maximum temperature coolant should not exceed a value of 55 degrees. Optimal loop loss is typically 10 degrees. That is, if your supply is 50 degrees, then the return will be around 40 degrees

The heat flux density per 1 m 2 is calculated as follows:

Q=Q/F, where: Q is the total value of heat loss in the room, (W); F - floor area, (m 2); q - heat flux density, (W / m 2).

Using the obtained density value heat flow(q), room temperature and floor surface temperature, we calculate the required temperature difference between the heat carrier and the pipe unfolding step using the appropriate table (attached in the example). Further, using the formulas G=3.6*Q/4.187*(t z -t p) and L=F/b we calculate required flow water through the floor heating system and the length of the pipe to be laid, where:

G - the amount of water consumed, (l / h); tz is the inlet temperature, (°C); tp is outlet temperature, (°C); b - pipe unfolding step, (m); F - floor area, (m 2).

An example of calculating a warm floor

So, let's say, by calculating the heat loss, we found out that in a particular room they are 1200 watts. We also know that we want a room temperature of 20 degrees. The useful area of ​​​​the warm floor is 20 squares. The floor will be parquet. Thermal resistance parquet is 0.1 m2K/W.

In general, the task is clear. First, let's determine the heat flux density per square square.

Q=1200/20= 60 W/m2

The calculation table shows that we can get the desired temperature of 20 degrees with a laying step of 25 cm. In this case, the temperature of the floor surface will be 25.3 degrees.

You can find more tables, as an option, in the book "Metal-polymer pipes and fittings" from the company Egoplast.

It is not difficult to determine the length of the pipe

L=20/0.25=80 meters

We find the water consumption according to the formula G \u003d 3.6 * Q / 4.187 * (t z -t p). The temperature according to the table is 50/40.

G=3.6*1200/4.187*(50-40)=103.2 kg/h=0.0287 l/s=0.0000287 m3/s

This data will help when setting values ​​on the flow meters of the distribution manifold.

Actually, we found out that for our conditions it is necessary to lay out 80 meters of pipe in increments of 25 cm. This is just the ideal length of the circuit. If the value exceeds 90-100 meters, it is advisable to divide the room into two circuits.

Is it possible without calculations?

In general, calculations are not necessary. But we still recommend doing heat loss calculations to make sure warm gender or none. If the floors pass, we act according to simple method. We lay a warm floor with a step of 15 cm, and in the areas of external walls with a step of 10 cm.

Video on the calculation of underfloor heating in the Valtec program

Calculation method the length of the heating cable and the step of laying the warm floor.

With the advent of underfloor heating systems, the task competent heating rooms have been made much easier.

The use of such systems in heating not only allows minimize costs for purchase and installation heating appliances, but also significantly expand the possibilities author's design for premises of any purpose.

Electric underfloor heating has several undeniable advantages over other systems, which is why it is most popular in space heating. Moreover, two ways of its application are possible - as the main heating system and as an element common system for creating more comfort in room.

Before purchasing and installing a warm floor, it is necessary to make correct calculation necessary system parameters in order to find a compromise between excessive heat generation in the room and spending money on purchasing Supplies. This will help save a lot of money at all stages of the installation work.

During the calculation it will become clear what characteristics a warm floor should have, its power, total area and the width of the step of laying thermoelements for different rooms.

Attention! When laying underfloor heating systems, it must be remembered that the placement of heating elements under stationary furniture without legs, and therefore good ventilation, is strictly prohibited.

This is due to the fact that without proper heat removal from the floor surface, the heating elements will constantly overheat and fail very soon. This nuance is also should be taken into account when calculating:

1. The first thing to do is calculate the total area of ​​the room, which requires the installation of a warm floor. To do this, you need to draw up a rough plan of the room on a scale and indicate on it the location of stationary furniture also on a scale. Then, from the total area of ​​​​the room, subtract the surface area on which the furniture is located. For example, the total kitchen area is 10 m 2. Furniture and Appliances occupy 4 m 2 area. Then the warm floor must be laid on the remaining 6 m 2.
2. Calculated general power heating system gender. Each room has its own norms for the power of a warm floor per unit area. The table below shows the main ones. It can be seen that for comfortable floor heating in the kitchen on the ground floor, the recommended power is 140-150 W / m. By normal multiplication, we find that the total power in this room should not be lower: 6 m 2 * 140 W / m2 \u003d 840 W. Knowing this indicator, it is possible to calculate the required length of the heating cable or the power of the mat when using products of this type.

Calculation of underfloor heating as the main type of heating

When using these systems as the main source of heat in a house or apartment, it must be remembered that the area that should be occupied by a heated floor should be at least 70% from the common space of any room.

If this parameter will not be respected, there is a high probability that the warm floor will not cope with its function.

Computed total heat loss in this room. Heat losses are present in all buildings without exception. They depend on:

• The climatic conditions in which the premises are operated.
• The presence and area of ​​windows.
• Degrees of insulation of walls, floor and ceiling.
• Orientation of the building to the cardinal points, etc.

During the construction of buildings in compliance with all requirements for thermal insulation of structures approximate power of heat loss calculated and is 100-130 W / m 2 for various premises in new houses and 150-170 W / m 2 in old dilapidated buildings.

When using underfloor heating as the main heat source, its power should exceed the heat loss by 1.5 times. That is, in the case of the kitchen described above, in which the heat loss is, for example, 1000 W, the power of the heat source, in our case, the warm floor should be: P = 1000 W * 1.5 = 1500 W.

Taking into account the fact that the heating elements will occupy only 6 m 2 of the area, we get: 1500 W / 6 m 2 = 250 W / m. It is this specific power that a square meter of a warm floor should have. When purchasing materials be sure to take this into account.

Important: if the result is a floor heating power of more than 200 W / m 2, it is recommended to consider the option of using an additional heating system.

Heating cable length calculation

Manufacturers produce a large assortment various heating cables, differing in length, power, cross section and, of course, quality. For purchase required amount cable For a specific room, it is recommended to use the formula:

where L is the length of the cable, S is the area of ​​the floor to be insulated, Pp is the power of one linear meter of cable.

For the described example with a kitchen, in the case of using a heating 20 W/m cable, and many manufacturers have this type of cable, we need 75 running meters: L=1500W/20W/m=75m.

The 75 meter long cable must now be properly laid over the entire required surface area of ​​6 sq. m. For this you need calculate laying step (h). The calculation is made according to the following formula:

where Su is the area for laying the cable, L is the length of the cable. Final result: h \u003d 6 m 2 * 100/75 \u003d 8 cm.

That is, it is necessary to lay the heating cable in such a way that between its turns there is distance of 8 centimeters. This is a completely normal value, although the initial data on heat loss in the example were fictitious.

In the case of choosing a warm floor as the main or auxiliary source of heating, it is necessary to carefully calculate the required power, from it the length of the cable and the laying step. This is avoid unnecessary costs, as well as to prevent a situation where the power of the heating system is not enough, and there will be a need to redo everything at the most inopportune moment.

The calculation of the warm electric floor Devi from the company Electrocontrol LLC, see the video: