High temperature heating. Low-temperature heating in the house. What is the heat power radiators of heating

There is no special statistics here, if the height of the floors allows, the choice is definitely in favor of water (liquid) coolants. All other things being equal, such heating will be much cheaper than electric.

Electrical heaters are also used, they are minimal in service and give ample opportunities in control not only with climate, but also by separate sections of the built-in converter. Therefore, such options are also very popular, especially considering that they do not require a deep channel for mounting.

Elegant solution showing the effectiveness of embedded converters, these are examples of heating rooms with a return. When the cooled coolant first enters the converter and gives the remaining heat heated air. This kind of "secondary" outlines are actually the most vivid examples of the efficient operation of the converters in low-temperature contours, where the temperature of the carrier can be 40 degrees. And the air temperature and the large amount of heating is provided by the physical dimensions of the converter, the largest area of \u200b\u200belements that give heat.

So now the most common converter is water, and in a smaller amount of electric. There are combined systems on the market, where electric heating helps in accurate temperature adjustment, or is generally aimed at efficient use of the converter. In such a system, electrical heating is an intermediate zero temperature of the coolant, and as long as they relate to exotic types of converters.

We only note that such a combination is advisable where the heat carrier is heated, in other situations, it is intelligent to warm the air to the electric heating element. And just a combination in which the coolant of the converter is heated with electricity, has a special advantage. For a closed converter of this type (with an electro-heating coolant), no pipeline is required, which allows you to upgrade the heating system in already ready-made houses with finishing.

Regardless of the type used, embedded convectors, except heating, as a whole help maintain better microclimate. Not only water, but also electrical convectors are not so "dried" air, so buy a moisturizer even at large sizes of the converter will not have.

There are other advantages about what is lower, and from the point of view of choosing what your converter will be heated, proceed from operating costs. Electric heating will cost more, and water will require maintenance and care costs. Shut-off valves, automation (or manual control) - all this compounds, which means there is a need to monitor leaks, and in general, pay attention to this system.

Some advantages of embedded converters in low-temperature contours

First of all, we recall that the converter allows you to use and hot, and low-temperature coolant, the result will still be good. But the design of the converter is such that eliminates the burn when the hot surface is touched (it is closed with a lattice) and the so-called. "Radiant" heater energy. This effect is well-known to everyone who passed past the hot radiator when it seems that from the cold wall "blows cold." The fact is that part of the heating of the radiator produces with the help of thermal radiation when the heated metal itself warms not the air, but everything around. This unpleasant effect of the embedded converter does not give.

Operation of the low-temperature heating system with a low temperature of the coolant significantly prolongs its service life. Pretty obvious conclusion, because there are no significant temperature deformations, the coolant does not work in critical modes and in general the system is more comfortable. Less salt sediments inside the pipes, longer serve all compounds, the pressure in the system may be lower than in the usual system, which reduces the risks of the hydrowards and emergencies.

The protection of the heating element of the converter allows manufacturers to use materials that have a very high heat transfer: copper, aluminum, etc. A number of modern radiators use similar materials, but the entire radiator is closed by a protective box, and this reduces air heating efficiency. Yes, and the thickness of the plates, the most effective heaters, in the radiator more, for considerations of the overall strength of the structure.

The aesthetics of the heating itself is also important. For low-temperature contours, decorative grilles of stone converters or other materials are applicable, which makes this heater with an interior element, and not a stain that you want to hide.

Installing the fan in converters with forced convection allows for efficient heat exchange. In the low-temperature circuit, the temperature difference of the temperature of the coolant at the entrance and the outlet can be 10-15 degrees, but this difference is enough for the heating of the room. Remember the beginning of the article, in the radiators to warm up the room, this difference can be 20-25 degrees, without using additional measures.

The heat insulation of the embedded converter reduces heat loss, and at the same time the floor around it is also heated, heating air. In the standard placement, the radiator warms well only the wall on which it is hanging, and the floor under it can be very cold.

The converter, from the point of view of the heating area, is close to the warm floor, but its shortage is deaf - low floor temperature. If the floor warm up to 25 degrees is completely solving the air heating problem, but it will be very problematic to walk by this floor. And at the same time the converter works just in the floor zone, providing a comfortable heating where it is necessary, it is always unpleasant to walk on the cold floor even in a warm room.

And, ultimately, in low-temperature contours, embedded convectors not only successfully and effectively solve the problems of warming up the premises, but also make it gently. In rooms that heated the converter, there are no so-called, high-temperature zones when it's hot near the radiator, and near the door is cool. Uniformity and impassionation of warming up is another advantage of this heating device, which we recommend that you pay close attention.

If, of course, you have the opportunity to plan the installation of such a heater.

A. Nikistov

The development of technical thought allowed the modern person to have a large selection of heating systems, depending on the requirements and material capabilities, which was not even among the previous generation. The gradual development of household heat energy led to the fact that the low-temperature housing heating systems have become increasingly popular, which will be discussed in this article.

Practice has shown that when comparing two heat sources - with high and low temperatures - the most comfortable conditions for humans are created by the low-temperature heating device, which provides a small difference in the room in the room and does not cause negative sensations. The upper limit of the so-called low temperatures, by definition of power engineers, is located in the area 40 ° C. Low-temperature heating systems using a coolant operate with temperatures of 40-60 ° C - at the inlet to the heat-producing device and at its output. And the systems of air, electrical and radiant heating are used and lower temperatures comparable to the human body temperature. So the very concept of low temperatures is quite conditional and, nevertheless, the use of coolant or other heat sources with a temperature of up to 45Simates the many advantages that affect the choice of such a housing heating system, and, thanks to its peculiarities, organically fits into use with renewable Sources of energy.

All heating systems impose certain requirements that are designed to make their most effective, comfortable and secure their use. Construction, climatic, hygienic and technological requirements are detailed in DBN B.2.5-67: 2013 in paragraphs 4, 5, 6, 7, 9, 10 and 11. These requirements allow us to minimize negative and at the same time increase the positive impact on the human body at the same time, Remitted heating systems.

It should be noted that one of the most important conditions for the efficiency of any heating systems is thorough care of heat loss, and for low-temperature systems it is almost the most important. Otherwise, such systems will be ineffective and excessively powerful, and, it means both financially expensive.

Classification

The low-temperature heating systems can be divided into the method of preparation of heat - on monolithic, bivalent and combined. Monolithic systems are characterized by using one or more heat-reproducing installations. Two heat generator with various principles of operation are used in bivalent, one of which can be included as an additional heat source at very low outdoor temperatures. Several heat-producing installations included in parallel form a combined heating system.

Heating of the coolant in all heating systems can be carried out by direct method or indirect. An example of direct heating is water heating boilers of various types, operating on solid, liquid or gaseous fuel, as well as electrical boilers. In the indirect way heats the coolant in the heat exchangers (boilers) or heat accumulators. This method is very widely used in systems operating on renewable energy sources - wind and solar.

Also, low-temperature heating systems can be divided by the type of coolant - liquid, gas, air and electrical, and by type of heating devices - surface, convection and panel-radial.

Description of systems

Low-temperature heating systems are becoming increasingly popular due to the fact that they are very harmoniously combined with equipment operating on renewable energy sources. In times, when traditional energy is becoming more and more expensive, this is an important factor.

Water heating

All systems of this type are characterized by three basic parameters - the temperature of the coolant at the outlet of the heat producing device (in this case, water heating boilers are used on solid, liquid, gaseous fuel and electric), the temperature at its inlet and air temperature in the heated room. Such a sequence of numbers is indicated in all boilers.
Modern low-temperature heating systems are mainly based on the European standard EN422, in which the concept of "soft heat" is introduced, which assumes the use of the coolant with a temperature at the outlet of the heat-producing device 55 ° C, and at the input - 45˚С.

This type of heating involves the use of circulating pumps in the circulation pump system, which are placed in the same way as in conventional heating systems. The most economical is the "open" systems with the placement of the expansion tank at the top point. Installation of pumps in the mains of the coolant supply allows you to avoid possible areas of the vacuum, which takes place when installing circulation pumps on the return highway.

In closed systems, working with high pressure, along with the circulating pump, it is necessary to use an automatic air vent and a reset valve, as well as a pressure gauge showing the pressure in the system. The expansion tank in this case is placed in a convenient place for the user.

One of the requirements that determine the efficiency of the open type of heating systems is the need for good thermal insulation of the expansion tank. Sometimes - in the case of placing it in attics of buildings - its forced heating is required.

One of the most common types of low-temperature heating system is the well-known "warm floor" (Fig. 1). Surface heating systems, for example, the production of Oventrop (Germany), include pipes, the installation of which can be carried out in the floor and in the ceiling, and into the walls. At the same time, the interior is completely incumbent.

Fig. 1. The heating system with the "warm floor"

In these systems, due to the mainly radiant heat exchange, there is absolutely no air movement, and the heat is evenly distributed on the room. Electronic programmable regulators significantly increase system efficiency.

The supply line of surface heating systems contains a coolant temperature of 40-45 ° C, which allows with the maximum effect to use the capabilities of condensation boilers, as well as alternative (renewable) energy sources. In the system, as a rule, a pipe made of stitched polyethylene with oxygen protected by a layer is used.

Steam heating

This type of heating is characterized by using a "saturated" steam as a coolant, which leads to the need to ensure the appropriate collection of condensate. And if one heating device is present in the heating system, which does not create problems, then with an increase in their number, the condensate is becoming increasingly harder and more difficult. The solution to this problem was in use as a coolant "cold" steam. Its role in modern systems of low-temperature steam heating plays, in particular, the chladone-114 is non-combustible, unadiplinary, odorless and chemically stable inorganic compound.

The system on the "cold" pair works through the use of heat allocated when condensing saturated vapors, which heats the heating devices. Condensate pipes operate in the "wet" mode, due to the condensate support. Condencators in this case are not needed - condensate Self comes back to the evaporator. PUBLIC PUMP is also required. Both steam pipelines, and condensate pipelines are mounted both horizontally and vertically. Moreover, it is absolutely necessary to observe the bias. In the case of vertical installation, the feeding pipe can be placed both from above and below.

Adjusting the system operating on the "cold" pair is carried out by exposure to the pressure of the steam and its temperature, for which the system is calculated on the pressure corresponding to the maximum possible pair temperature.

Sectional radiators and convector panels are commonly used as heating devices in the low-temperature steam heating system. To adjust the heat transfer, each heating device is supplied with a membrane valve.

Aerial systems

Using this type of systems (Fig. 2) is quite limited. This is influenced by several factors. First, a fairly low degree of heat exchange between air and a heat derivative device or heat exchanger. Secondly, on hygienic considerations. Air flows transfer dust, and aircraft and heat exchangers create good conditions for the development of unwanted bacteria and microorganisms, and require special protection. And, thirdly, such systems are very material intensive, and therefore have a high cost.

Fig. 2. Air heating system

But despite this, low-temperature heating air systems can be used in the following cases:

if it is necessary to provide centralized heating at low air movement speed in the channels. This method is suitable for heating small houses and cottages with a plinth duct;
if you need to provide central heating at high air velocity in the channels - high pressure system. In this case, special air distribution equipment is required, providing uniform air intake in all rooms and having noise absorbing properties. Adjusting this system is carried out in two ways: primary - on the heat exchanger, and the secondary - the number of inlet warm air;
if you need a local heating of several rooms or one big. Such systems are familiar to everyone at large stores - air curtains at the entrance to the room, and additional air ducts with warm air in the required places are used.

Electric heating

This system is represented in the market of heating systems by a variety of manufacturers. It is based on the principle of heating a special resistive cable (Fig. 3) by electric shock. The heat removed from the cable is transmitted to the environment, creating a soft heating of the room. Equipment of the system may include heating cables or ready-made mats, thermostators and installation kit, providing fast and easy installation.

Fig. 3. Electric "Warm floor"

Constructive elements of systems

All heating systems, as mentioned above, are intended to maintain the optimal and comfortable ratio of three parameters - the temperature of the coolant after the heat producing device, the temperature of the heating device and the temperature of the air room. To ensure such a relationship can be the right selection of important elements of the system.

Heat production devices

All heat production devices can be divided into three groups.

The first group is heat generators based on the use of traditional fuel and electricity. In the main mass, these are various water boilers operating on solid, liquid, gaseous fuel and electrical energy. Even for indirect heating of the "cold" steam in the steam systems of low-temperature heating, all the same water heating devices are used.

In this group of instruments, a household condensation boiler can be noted, which appears as a result of innovative developments on the rational use of water vapor generated during fuel burning. Studies that are aimed at a more complete use of energy and at the same time minimizing the negative environmental impact has made it possible to create a new type of heating equipment - a condensing boiler - allowing additional heat from flue gases by means of condensation.

For example, the Italian manufacturer of BAXI produces a range of condensation boilers both outdoor and wall-mounted performance. The Luna Platinum wall-mounted wallpaper (Fig. 4) consists of single-circuit and double condensation boilers, with a capacity of 12 to 32 kW. The key element is a stainless steel heat exchanger AISI 316L. An electronic board is controlled by various components of the boiler, there is a removable control panel with a liquid crystal display and a built-in temperature control function. The burner power modulating system allows you to adapt the output power of the boiler to the energy consumed by the building in the range of 1:10.

Fig. 4. Condensation boiler Baxi Luna Platinum

The second group - installations that use the heat of non-systemic coolants. In such cases, heat accumulators are used.

The third group includes devices using an external coolant for indirect heating. They successfully apply surface, cascade or bubble ball heat exchangers. It is this type that is used to heal the "cold" steam in steam low-temperature heating systems.

Heating devices

Heating devices are divided into 4 groups:

instruments with equal surfaces with surfaces, both on the side of the coolant and air side. This type of instrument is known to everyone - these are traditional sectional radiators;
convection type devices in which the surface area in contact with air is much larger than the surface from the coolant. In these devices, heat emissions are secondary;
plastic air heaters with motivating air flow;
panel type devices - floor, ceiling or walls. In this line of heating panels, for example, you can mark the Czech panel steel radiators of Korado called Radik, produced in two versions - with side connections (KLASIK), and with the bottom with the built-in thermostatic valve (VK). Panel steel radiators also offers Kermi (Germany).

Fig. 5. Panel steel radiator Korado

The heating devices of low-temperature systems include various kinds of sectional and panel heaters, heating convectors, calorifers and heating panels.

Heataccumulators

These devices are needed in bivalent low-temperature heating systems, which use energy from renewable sources or dischargeable heat. The heat accumulators can be liquid or solidized using the heat capacity of the aggregate for the accumulation of heat.

Widespread devices are increasingly obtained in which heat is highlighted at the time of phase transformations. The heat accumulates in the process of melting the substance or when the crystalline structure undergoes certain changes.

Thermochemical heat accumulators are also working effectively, the principle of operation of which is based on the accumulation of heat as a result of chemical reactions occurring with heat release.

Heat batteries can be connected to the heating system both by the dependent scheme, and on an independent, when heat is accumulated from the non-systemic coolant.

Thermal batteries can also be ground, scalging and even underground lakes can be used as heat drive.

Ground thermal batteries are obtained when placing registers made of pipes, with a pitch of one and a half or two meters. Rock heat accumulators are equipped by drilling vertical or inclined wells in rock rocks to a depth of 10 to 50 m, where the coolant is injected. The use of underground lakes as heat accumulators is possible in the case of placing in the lower layers of water pipes with the coolant injected in them. Heat selection is carried out from pipes placed in the upper layers of underground lakes.

Heat pumps

When used in low-temperature heat source heating systems, the temperature of which is lower than the air temperature in the room, as well as to reduce the material intensity of heating devices, thermal pumps can be included in the system (Fig. 6). The most common devices of this group are compression thermal pumps, which give the temperature from 60 to 80 ° C during condensation.

Fig. 6. The principle of operation of the heat pump

The effective operation of the heat pump in the low-temperature heating system provides inclusion in the contour of the evaporator of a thermal battery, which contributes to the stabilization of the temperature of the evaporation of the cold "steam. Adjusting this system is carried out by changing the heat transfer of the pump itself.

Advantages and disadvantages

Low-temperature heating systems conquer their supporters by creating more comfortable conditions in the room, rather than traditional - with high heating of heating devices. There is no excessive "deduction" of air, there is no excessive - again excessive - dusting of the room due to the inevitable movement of air with very hot heating devices.

The use of heat accumulators in the system makes it possible to accumulate heat and instantly use it if necessary.

Low temperature scatter - outlet from the heat-producing device and air indoor - makes it easy to adjust the system using programmable thermostats.

As for the shortcomings, it is essentially one - the cost of the completed system is somewhat, and even at times higher than the traditional high-temperature.

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We build or reconstruct a private house, got involved in the boar of apartments. We equip the office, warm garage, heated room for other purposes. The heating system was thought out, the main equipment was picked up: the boiler and its strapping, a boiler, a warm floor system. Either, if it is an apartment, decided to replace the existing heating device more aesthetic and efficient, maybe add a few additional sections of the old battery. We assume that we have already made the choice of the type of heating instruments: type-section chig-iron, aluminum batteries, bimetallic devices or ready-made panel steel radiators. I will not forget that the batteries must withstand the pressure of the coolant in the system, which in a multi-storey building is much higher than in the cottage. To achieve thermal comfort, it is important for us to correctly perform the calculation of heating radiators.

Principles of calculation

To ensure the necessary temperature in the room, the calculation of the power of heating radiators and the entire system must take into account the heat loss from each room and the climatic conditions of the region. Heat engineers in the manufacture of the project determine the thermal balance of the outer walls, roofs, the base of the building, window and door structures. Also taken into account air exchange in the ventilation system, the height of the premises, the movement of air flows and many other factors. The fundamental document prescribing the principles of designing the heating system - SNiP 2.04.05-91. Designers enjoy a number of regulatory acts (a total of up to two dozen), regulating the heating device for buildings and premises of various purposes.

The accurate calculation of the sections of heating radiators for all the rules is quite complicated, and make it yourself, without possessing special knowledge, not easy. During the construction of a serious country house, it makes sense to refer to the specialists and order a complete project of heating: rational solutions, thermal comfort and optimal fuel consumption are justified. If there is no such possibility, you can make an approximate calculation of heating batteries yourself.

What is the heat power radiators of heating

Thermal power, heat transfer or heat flow of the heating device indicates the number of heat energy (in kilowatts or watts), which radiator or one modular element (section) is able to put into the room per unit of time (hour). Less often meets designation in calories / hour. One watt is 0.86 calories. The magnitude of heat transfer depends not only on the design of the radiator, its size, the material from which it is made. The parameters of the coolant are not less important: its temperature and the speed with which the fluid flows through the batteries. For most heating devices, thermal power is indicated with standard coolant temperature values \u200b\u200bat 60/80 ° C. Accordingly, when operating services from budget generaries are amenable to heat and launch boiling water into the system (rarely, but it happens), the heat transfer will increase. It will go a little warm water at low speed (it happens much more often) - drops. Significantly affects the magnitude of the heat flux and the method of connecting the device.

It should be noted that not all connection schemes provide complete heat transfer of the heating device. The most common standard side (1), for other cases (3, 4), a downward coefficient is introduced during the calculation.

The heat transfer of one section in the traditional cast-iron radiator of the Soviet sample is 160 W. To determine the total battery power, multiply this digit to the number of sections.

Aluminum radiators are also sectional. The heat flux depends on the model, but with a standard inter-axis height of 500 mm, an average of 200 W for one section. That is, such aluminum sections will be required by about 20% less than cast-iron.

Aluminum radiator design. In the standard embodiment, the value A is 500 mm. Attention should be paid to distances from the external edges of the device to the floor and the windowsill. If they are less than the specified, heat transfer slightly down

Panel steel radiators are intimidable and have a fixed heat transfer. As an example: Depending on the design, a standard height panel and a length of 800 mm can give a heat flux from 700 to 1500 W.

Simplified calculation

In the central regions of Russia, for heating a residential room with one outer wall in a typical panel house, it will take about 100 W thermal energy to one square meter of the square. This is a very estimated digit. If the apartment is located on the first or last floor, it is worth adding about 20%. For the corner room, increase the number one and a half times. We will not forget that there is a dependence on the connection scheme, if necessary, take into account the correction factor. This is a battery of ten cast iron sections. Naturally, for Yakutia and the Krasnodar, the importance of heat transfer per unit area will differ significantly. Thus, for the Moscow region on a room of 16 m 2 in the standard "panel", 1600 watts will be required.

Modern house with walls from "warm" cellular blocks, and even with thermoshube, energy-efficient glazing will have much smaller heat loss and the required radiator power should also be lower. Some sellers of heating equipment make it easier for potential buyers the choice by placing a calculator on their website to calculate the number of heating radiators sections. With the help of this online service, it is realistic to make a more or less accurate calculation of the heating radiator on the room.

Radiators location plan, one of the plurality of the "right" project of the heating system. For each room, the design value of heat loss (numbers in a rectangle) is indicated. During the construction of expensive apartments, it is not worth saving on project work

Need power

Preferably. You do not always get the coolant of the desired temperature from the HSA, so it is worth increasing the battery power by 20-25%. At the entrance It is advisable to put a heat regulator: a thermostat or a regular ball crane.

"Right" radiator installation (5). The thermostatic valve (4) will provide a permanent maintenance of the desired temperature in the room, connecting parts (1-3) will help you quickly remove and install the battery back. Bypass (jumper between the supply and discharge pipe) will enable the heat carrier to circulate on the riser and when the device is removed, so as not to infringe the interests of neighbors around the house

Low-temperature heating systems and calculation of radiators

In Europe, prevail, and in Russia modern low-temperature heating systems are increasingly used. They are built on the basis of energy-efficient condensation heating boilers, thermal pumps. To obtain the maximum economic effect, for radiator heating, as well as for warm floors, low temperature coolant is used - 40-55 ° C. The heat transfer of radiators is reduced by about 1.8 times. Accordingly, they must have greater power and dimensions. Despite the rise in the system, such an approach is justified: rationally designed, correctly mounted and competently adjusted low-temperature system makes it possible to achieve significant gas savings. And thermal pumps do not need fuel at all. To calculate such systems, all known manufacturers indicate the heat transfer of instruments for various parameters of the coolant. The calculation of the amount of heating radiators should also take into account the influence of warm floors.

The ratio of the efficiency of traditional and modern condensing gas boilers. To achieve this savings, the radiators should also circulate the coolant with a low temperature. Accordingly, the heat transfer of devices should be taken on the basis of indicators in 40-55 ° C

In conclusion, let's say that the heating device should not be closed with something: dense curtains, a solid decorative screen, closely the driven furniture will significantly reduce its effectiveness. If the fashionable windowsill completely closes the battery from above, the warm air passes the surface of the window glass, and it can be overlooked cold and "cry". In this case, the windowsill should be placed in the windowsill.

The question is what low-temperature heating, many people occur. Typically, such systems are characterized by heating the coolant to 60 degrees Celsius. At the same time, at the entrance to the system, it has a temperature of about 40 degrees, and at the output - about 60. Consider how it is achieved.

Temperature mode of heating systems can be described by three characteristics:

. The temperature of the coolant at the entrance to the boiler.
. Outlet temperature.
. Temperature in the heated room.

The boiler data must be indicated in the process of products in this sequence. The heating systems of the traditional type (including central heating) were calculated in such a way that water should have a temperature of about 80 degrees at a temperature of 60 degrees at the inlet. However, these days such indicators are somewhat outdated. The temperature can be reduced or heated, or by the user itself. European boilers, which today practically completely outlined Soviet heating analogs, work in several other schemes.

According to the European standard, the normal mode of operation of heating systems implies a temperature of 60-75 degrees Celsius. But here it is said about the concept of the so-called "soft heat", which involves the parameters of the system with a temperature of up to 55 degrees. And it is precisely this mode that can be regulatory in the near future, considering all tightening requirements for savings. In this way, installation of warm floors It is becoming increasingly relevant.

About "warm floors", perhaps, heard everything. It is this system that acts one of the most striking examples of low-temperature heating. In addition, most of the owners of the private house today reduce the temperature of the boilers to "units", in order to bring the temperature of coolants to 50-60 degrees.

What advantages have low-temperature heating

For installation of water warm floorsYou get the following advantages:

1. The main advantage is the level of comfort. It's no secret that too hot batteries are dried by air, forming an excessive convection in the house, which raises a lot of dust in the house, having a negative impact on the human body.
2. Efficiency. Refusing intensive heating in favor of the sample, which is characterized by separate temperature adjustment, you can save up to 20% of coolants.
3. Technological economy. Using warm pipe mode, you can discover at once two possibilities for heating - condensing boilers, characterized by the efficiency of up to 95%, and solar collectors that allow you to get "free" energy.

By eliminating the main sources of heat loss and wanting to reduce costs when, after 5-10 years, the system will pay off, household owners can begin to re-equip the heating systems to a more economical mode of operation.