The most important task of technology development is an increase in energy efficiency. To solve this problem in heating systems, the most effective way is to reduce the temperature of the coolant. That is why low-temperature heating is today a key trend in the development of modern heating equipment.
The low-temperature heating system during operation consumes a much smaller amount of coolant, compared with the traditional system. Due to this, significant savings are ensured. An additional advantage is to reduce the volume of harmful emissions into the atmosphere. In addition, working with a "soft" temperature regime allows you to use alternative types of equipment - heat pumps or condensation boilers.
The main problem of the development of low-temperature heating has remained a long time that at low heating temperature it was very difficult to create comfortable conditions in heated rooms. However, with the development of construction technologies, allowing to build energy-efficient buildings, this problem has been solved. Application of modern construction and thermal insulation materials It makes it possible to significantly reduce thermal loss of buildings. Due to this, the low-temperature heating system can warm the house qualitatively and effectively. The achieved effect on the economy of the coolant significantly exceeds the additional costs that have to carry for the heat insulation of buildings.
Initially, only so-called panel heating systems were considered as low-temperature, the most common representatives of which are warm floors. It is characterized by a significant surface of heat exchange, which allows at a small temperature of the coolant to provide high-quality heating.
Today, the development of production technologies contributed to the opportunity to use for low-temperature heating and radiators. At the same time, batteries must meet increased energy efficiency requirements:
TM OGINT offers energy-efficient aluminum radiators, which fully comply with the listed requirements and are ideal for the configuration of low-temperature heating systems. At the same time, they are made in full compliance with Russian standards and are fully adapted to domestic operating conditions.
Thus, the use of aluminum radiators of the OGINT Delta Plus model when creating low-temperature systems gives an important advantage compared to warm floors. The optimal indicators of savings and comfort are ensured in cases where the heating system quickly responds to changes in the outer temperature (when it increases, the temperature of the coolant decreases, and with a decrease - increases). Modern automation used on boiler equipment gives all the possibilities for this. Minus warm floors lies in their inertia. The radiator systems are able to respond to changing external conditions almost instantly.
Low-temperature systems have a number of significant advantages:
The shortcomings of the heating systems of this type are relative. So, a certain minus can be called increased requirements for radiators used.. However, the use of Ogint Delta Plus batteries is completely solving all the problems of choice. heating devices.
It should also be noted that with severe frost low-temperature systems It can not always cope with the heating of buildings. At the same time, the system without any problems can be transferred to work at a higher temperature mode in the presence of such a need.
In general, low-temperature heating systems are more efficient, economical and safest compared to traditional systems. Therefore, today you can confidently say that the future is behind low-temperature heating.
Low-temperature heating of buildings in its design consists of a wall-mounted low-temperature, as well as outdoor heating. Modern wall heating looks like this: pipes, with the help of which the flow of warm water from the bottom, and the one that comes from above, then it is paired towards the wall, in most cases, parallel to the floor lines. After that, the pipes are fixed with the help of special clamps, they are also close to a special plaster made on the basis of chalk and cement.
In accordance with the established standards, the surface of the wall of the pipe must be located at a distance of 10 millimeters - this can contribute to the operational heating of the premises. The main rule of the installation of wall heating is that for as much as possible heating of the room, it is required to install pipes by about a third of the walls of the walls. For example, in the event that the area of \u200b\u200bthe walls of the room is 30 square meters, then for heating of such a room, the pipe will need to be laid on an area of \u200b\u200bequal to 10 square meters of walls.
Outdoor low-temperature heating works in the same way as wall heating. However, outdoor option It is known as easy to install and, as a result, more affordable. Outdoor heating has a particularly high efficiency, if used for wet premises, or for hallways - in principle, for any premises, the floor of which is laid out with a stone or tile. Outdoor heating, if it is compared with a wall mounted, is significantly more slower, and, accordingly, he warms the room longer.
The main difference between low-temperature heating systems from standard models lies in the fact that in an ordinary radiator the water temperature is about 70 degrees and more, and in low-temperature systems, water is heated to indicators of 30-35 degrees. Thus, the heated water comes along pipes or by plastic hoses installed in the floor or in the wall.
The advantages of low-temperature heating of buildings include the fact that energy costs under the conditions of use of low-temperature systems are significantly lower than with the traditional method of heating. At the same time, the pre-heating of water to indicators in 20-25 degrees can be carried out using a solar radiator mounted on the roof.
kzh to the advantages of the system include the fact that low-temperature heating, installed in the rebuilding, more economically, for the reason that there is no need to perform insulation of pipes to prevent heat loss - it is known that they are mounted directly into the walls that, in fact, perform Heating room. Therefore, heat loss, as such, no. It is known that plastic pipes are not exposed to oxygen and can be operated for a long time without the risk of deposits and damage. Especially it should be noted that indoors with the installed wall or with outdoor heating The circulation of the existing dust is significantly reduced. For this reason, people sensitive to dust makes sense to give its preference to low-temperature heating systems.
It is necessary to take into account the fact that the water itself is heated at all is not air, but the surface of the walls, forming even in the conditions of the same room temperature a special feeling that in a room with a low-temperature heating system is much warmer. Also in this room there is always the opportunity to establish both standard heating.
Added: 04/28/2018 16:39:05
www.stroi-baza.ru.
The most important task of technology development is an increase in energy efficiency. To solve this problem in heating systems, the most effective way is to reduce the temperature of the coolant. That is why low-temperature heating is today a key trend in the development of modern heating equipment.
The low-temperature heating system during operation consumes a much smaller amount of coolant, compared with the traditional system. Due to this, significant savings are ensured. An additional advantage is to reduce the volume of harmful emissions into the atmosphere. In addition, working with a "soft" temperature regime allows you to use alternative types of equipment - heat pumps or condensation boilers.
The main problem of the development of low-temperature heating has remained a long time that at low heating temperature it was very difficult to create comfortable conditions in heated rooms. However, with the development of construction technologies, allowing to build energy-efficient buildings, this problem has been solved. The use of modern building and thermal insulation materials makes it possible to significantly reduce thermal loss of buildings. Due to this, the low-temperature heating system can warm the house qualitatively and effectively. The achieved effect on the economy of the coolant significantly exceeds the additional costs that have to carry for the heat insulation of buildings.
Initially, only so-called panel heating systems were considered as low-temperature, the most common representatives of which are warm floors. It is characterized by a significant surface of heat exchange, which allows at a small temperature of the coolant to provide high-quality heating.
Today, the development of production technologies contributed to the opportunity to use for low-temperature heating and radiators. At the same time, batteries must meet increased energy efficiency requirements:
Thus, the use of aluminum radiators of the OGINT Delta Plus model when creating low-temperature systems gives an important advantage compared to warm floors. The optimal indicators of savings and comfort are ensured in cases where the heating system quickly responds to changes in the outer temperature (when it increases, the temperature of the coolant decreases, and with a decrease - increases). Modern automation used on boiler equipment gives all the possibilities for this. Minus warm floors lies in their inertia. The radiator systems are able to respond to changing external conditions almost instantly.
Low-temperature systems have a number of significant advantages:
The shortcomings of the heating systems of this type are relative. So, a certain minus can be called increased requirements for radiators used.. However, the use of Ogint Delta Plus batteries completely solves all the problems of selecting heating devices.
It should also be noted that with severe frosts, low-temperature systems can not always cope with the heating of buildings. At the same time, the system without any problems can be transferred to work at a higher temperature mode in the presence of such a need.
www.ogint.ru.
Any heating system in the house is designed to provide comfortable living conditions for its residents in its premises.
What is the low-temperature heating system?
This is such a heating system, where the ratio of the temperatures of the output and input flow of the coolant fluid is equal to the ratio of its temperatures - 60/40 ° C. Of course, the distinction is quite conditional, and the matter here is not only in this.
If you look at the root of the "temperature" question, then with the current practices of the functioning of conventional heating systems, we can say that in the transition heating period in each house or apartment with individual heating, we actually use the operation of the heating system close to this.
In this heating period, on the regulator gas boiler Our heating system, we, as a rule, expose the temperature values \u200b\u200bof its operation 60/50 ° C.
If we talk from the standpoint of comfort in the room and safe operation System S. various temperatures heating radiators at the same time, then it is clear that warm radiator, with a temperature of 60 ° from the low-temperature heating system of the house, much more comfortable, and most importantly safer, rather than the radiator of the ordinary heating system with its temperature of about 80 ° C.
Also, widely known among the population, a variety of low-temperature heating system is the heating system "Warm floor", but the heating radiators are quite efficient and often used in this system. And now let's talk about the temperature modes of functioning of all modern Systems Heating, as well as about the merits of low-temperature heating systems.
A little about temperature modes and low-temperature heating.
Any, the specified temperature mode of the system has three parameters:
The temperature of the fluid coolant at the outlet from the boiler.
The temperature of the coolant fluid at the inlet of the boiler.
Indoor air temperature.
It is in this sequence of the number in all accompanying documents to boilers and are affixed.
In our, "traditional" heating systems, their calculation on temperature parameters is made in such a way that at the outlet of the boiler, the temperature should be within +70 - +80 ° C, and at the input - about +60 ° C.
Approximately the same standard is also for heating systems in Europe, where according to the norms of the EN-442 standard, the optimal parameters for the heating systems in the ratio of output / input, which are 75/65 ° C. In the same standard, such a concept as a "soft body" is also laid, which corresponds to the temperature regime in the low-temperature heating system with an output temperature after boiler +55 ° C and its inlet temperature is approximately +45 ° C.
Therefore, for the calculations of modern low-temperature heating systems, nevertheless, it will be preferable to be attached to the European standardization standards, since it is precisely all import boilers that are configured at our majority.
Yes, in principle, according to experts, the soft temperature regime of heating according to the European standard EN-442, this is the future of all existing heating systems.
On the main advantages of low-temperature heating.
Regarding the advantages of this heating system, then they are as follows:
The main advantage of the low-temperature heating system is its comfort, for already "language in the language" it became the view that strongly heated radiators of the usual heating system are significantly dried by air indoors, as well as a large amount of dust in a room arising from the movement of air layers ( convection) with such heating.
It is difficult for all these prejudices, but it is necessary to recognize one thing that, after all, a warm radiator of the low-temperature heating system of the house is much more comfortable and preferable, its hot fellow in the conventional heating system.
Specialists argue that the temperature of the radiator or other heating device in the room, closer to the temperature, which is required in this room, the cozy and comfortable person here is to be.
The heating system using low-temperature technologies also provides for the possibility of using high temperatures in the houses of the house. For example, during the sufficiently strong, our "Siberian" frosts is permissible.
The ability to accumulate (accumulates) of energy in the low-temperature heating system through the use of heat accumulators in it, for the lower the temperature of the coolant fluid circulating in the heating system, the greater the thermal energy "postponed" about the supply.
Easyness in adjusting low-temperature heating systems by using programmable thermostats, since the temperature variation, the outlet of the heat generating system of the system and the room temperature is significantly lower than with a conventional heating system.
Conclusion.
Summing up the small result of our conversation, it can be said that the system of low-temperature heating at home is more perfect, safe and economically beneficial than the application in heating of our homes of conventional, high-temperature heating systems. Therefore, for low-temperature heating - the future!
ingsvd.ru.
Ventilation with heat recovery is a system with a heat return process. In our case, heat recovery means the process of heating from the room with warm air of cold incoming air, which is included in the house for ventilation and ventilation. In other words, we return to the house that we collect from all the premises of the house. Before throwing away the exhaust fumes from the house, we skip it through the recuperator, where we select the heat you need, and then heat this heat ingoing cold air to a certain value. In such a process, a brilliant thought was laid - why use at home for heating at home additional energy, which is very costly and costs, if it can be obtained absolutely free.
Recoveraders are two species: lamellar and rotary.
Planted. IN this variant The air outlet heats the heat exchanger plate, gives them their heat and removes it cold. Incoming fresh air takes heat from the plates of the heat exchanger, heated and delivered to the room already heated. The effectiveness of the plate recovery is up to 60%, depending on the installation. Key features The designs are simplicity and low cost, while the flows of the incoming and outgoing air are not mixed, which provides 100% ecology of such an installation.
Rotor. In the second embodiment, the foundation of the installation is an aluminum drum, which takes heat from the outgoing air and gives it an incoming. The rotary heat recuperator has a higher efficiency, its energy efficiency reaches 80%. In contrast to the lamellar version, it does not need to be removed moisture, which is collected in the form of condensate, in this embodiment it is delivered to the moistening of the desired premises, which becomes especially relevant in dry winter. Both options ventilation units Air filters, humidity sensors and spent gases plus system control panels.
studfiles.net.
The functioning of any type of heating system is directed to the creation of optimal temperature mode For residents at home. The established stereotype in respect of the "correct" heating implies a simple criterion for determining its quality - the more hot heating devices, the better. But is it? Is high-temperature heating really provide the highest possible comfort and does not have a negative impact on the human body? 
Climatic, medical and technological studies have proven that it is not. The most desirable and safe option for the formation of the comfortable parameters of the microclimate of the premises is the low-temperature RѕS.RѕРїРїР »Р рРѕРμРμРѕРѕРѕРѕРјРμ, which is not only effectively, economically and practical, but also positively affects the physical condition of the person.
It is important to know that the phrase " low temperatures»Pry is quite conditionally and is a comparative value in relation to a classic heat source with a high temperature of the working medium (+ 70-80C). The low-temperature heating of a private house operates with a coolant, heated to + 40-45 / 55-60 ° C, where smaller temperatures show the state of the working medium at the inlet to the heat generator, and large on the outlet. In Europe, more creatively and accurately approached the definition of low-temperature heating by entering into circulation the concept of "soft heat" (standard EN422).
The heating systems with a reduced temperature of the working medium can be created on the principles of convective or radiation heat transfer:
Radiator low-temperature heating in a private house
Different heating devices are used, among which the panel type radiators with the lower or side connections have proven themselves. Radiator low-temperature heating in a private house is designed on the total bases, but it requires a thorough selection of heaters with an increased power due to non-standard coolant temperature.
Surface low-temperature heating
Bright and famous for each example of using low-temperature heating in a private house is the system "Warm floors". Pipes are placed on a prepared and heat-insulated surface of a spiral, a zigzag or snake at a distance of 100 mm closer and no further than 300 mm from each other. To achieve high efficiency and uniformity of heat transfer Length of the contour should not exceed 75 meters. Therefore for large premises Or when installing outdoor heating, the distribution manifold is installed in several rooms.
Similar technology is used for arrangement surface heating in the walls. Pipes with a specific laying step are mounted in the wall parallel to the floor and fixed with special fasteners. The coolant moves in the direction from top to bottom. As a wall base for heat transfer, a chalk-cement plaster is performing, which is distinguished by strength and excellently decorates pipes. Surface heating does not create forced air movement, due to which the heat is evenly distributed over the entire area of \u200b\u200bthe room, forming optimal conditions For accommodation, sleep and rest.
The low-temperature heating system contains a working medium with a temperature of 40-45 ° C, which is very critical for most classic boiler plants due to the threat of the formation of caustic condensate on heat exchange surfaces (dew dropping point). Therefore, the design of low-temperature heating in a private house and the selection of appropriate equipment must be carried out by specialists.
In the case of the actual presence of a heat generator that does not fully ensure the comprehensive demands of the temperature regime for the formation of "soft heat", it is possible to use a hydraulic heterlet or a thermostat pump. But optimal option The heat source for low-temperature heating is condensing boilers, which are specifically designed for this type of heating system. Special scheme implemented in such boiler installations useful use Properties of steams formed during the combustion of fuel.
In comparison with the traditional high-temperature heating system, the scheme using "soft heat" has a weighty and at the same time relative drawback - a higher cost of the completed project, especially if necessary for additional insulation of the house. Otherwise, low-temperature heating in a private house is characterized only by positive moments:
a) Separate temperature settings in contours;
b) more efficient energy resources;
c) the possibilities of additional water heating by alternative heat sources;
d) the ability to function when the boiler is turned off due to the operational redistribution of thermal energy accumulated in the heat accumulator;
In a situation where all sources of heat loss, low-temperature heating in a private house will quickly pay off, even with regard to regular maintenance Boiler room and growing fuel prices. According to experts, soft temperature regime due to their comfort, security, versatility and economy will be worthy competition to high-temperature systems and eventually takes their place.
www.vashdom.ru.
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 heating systems Three characteristics can be described:
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. Thus, it becomes more and more relevant.
ABOUT " warm floors"Perhaps everyone heard. 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.
For installation of water warm floorsYou get the following advantages:
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 start re-equipment of heating systems on more economical regime Work.
geo-comfort.ru.
In the conventional heating system, the water temperature at the outlet of the boiler is significantly higher and is approximately 70-80 degrees, while the temperature of the return temperature is 20 degrees.
It should be noted that low-temperature heating systems are used not because they are better and more efficient, but because only with their help you can warm the house using heat pumps for this, geothermal heat sources or condenser boilers heating.
The so-called traditional heating boilers in low-temperature systems can only be used in a set with an elevator node that ensures the mixing of a cold coolant with hot water From the boiler and bringing the temperature of the coolant to the required (55-45) parameters.
Long exploitation of a conventional boiler for heating low-temperature reversal can lead to excessive condensate formation in chimney and premature it fails. Therefore, in low-temperature heating systems operating on conventional heating boilers, the coolant from the return pipe before the feed to the boiler is sure to heat up using the heat generated by the boiler.
All this complicates the design of the heating system and leads not only to an increase in its value, but also significantly complicates the process of operation and maintenance.
Only condensing heating boilers can operate on a low temperature coolant.
As already mentioned, low-temperature heating is focused on the consumption of thermal energy produced by thermal pumps, as well as heat obtained from the Sun and geothermal heat. It is these sources that are optimal for low-temperature systems. If it is decided to use low-temperature heating without the use of renewable energy sources, it is easier and more economical to establish a condensing boiler.
But the system of obtaining "soft heat", as often referred to as low-temperature heating, will only be proper choice Heating devices.
Heating Instruments for Low-Temperature Systems
Ordinary radiators for low-temperature heating systems are not suitable. They simply will not be able to work at full capacity, and in the house will be cold. Heat the house with a low-temperature heating system will have to the help of heating surfaces. It can be warm floors or warm walls. The ratio is simple: the greater the warming surface, the warmer will be in the house.
It should be noted that low-temperature heating systems have a number of advantages:
Unfortunately, today it is premature to talk about real savings when using low-temperature heating.
In our country, it is cheaper to drown gas, using traditional boilers complete with convectors and heating radiators.
For those who want to enjoy soft warmth from heating surfaces, it is better to establish a condensation boiler. It costs more, but allows you to reduce gas consumption by 15-20%.
Radiators are usually perceived as elements of high temperature systems. But for a long time, such a point of view became obsolete, today's heating devices can easily be installed in low-temperature systems due to unique technical specifications. This saves such precious energy resources.
Recent decades, leading European manufacturers of heating equipment have begged on how to reduce the temperature of the coolant. An important factor for this was the improved thermal insulation of buildings, as well as the improvement of radiators. As a result, in the eighties, the temperature parameters were reduced to 75 degrees to feed and up to 65 to the "return".
At the time when various panel heating systems became popular, including floor, the feed temperature decreased to 55 degrees. Today, at this stage of technological development, the system can fully function even at a temperature of thirty-five degrees.
What do you need to reach the specified parameters? This will give the opportunity to use new more economical heat sources. This will allow to significantly save on energy resources and will reduce the emission of harmful substances into the atmosphere.
Some time ago, the main options for heating the room with low-temperature carriers were considered warm floors or convectors with copper-aluminum heat emissions. Also in this series included panel radiators made of steel, which have already been used for quite a long time in Sweden as part of low-empected system heating systems. This was done after a number of experiments and collecting a certain evidence base.
As studies have shown, the results of which were made public in 2011 at the seminar at the center of Purmo-RadsoN in Austria, much depends on the thermal comfort, the speed and accuracy of responding to the heating system to change the weather and other conditions.
Usually a person is experiencing temperature discomfort when there is temperature asymmetry in the room. It directly depends on which heat-pumping surface in the room and where it is, as well as from where the heat flow is oriented. Not the latter role is played and the temperature of the floor surface. If it goes beyond the range of 19-27 degrees Celsius, a person can feel some discomfort - it will be cold, or vice versa, too hot. Another important parameter - The temperature difference vertically, that is, the temperature difference from the legs to the human head. This difference should not be more than four degrees Celsius.
The most comfortable person can feel in the so-called moving temperature conditions. If the internal space includes zones with different temperatures - this is a suitable microclimate for good well-being. But it is not necessary to do so that the temperature differences in the zones are significant - otherwise the effect will be directly opposite.
According to the participants of the seminar, the ideal thermal comfort can create radiators that transmit heat both using convection and radiation method.
Improving the isolation of buildings plays the evil joke - as a result, the premises become thermally sensitive. He strongly affects the climate in terms of such factors such as sunlight, household and office equipment, the accumulation of people. Panel heating systems are not capable of responding so clearly to these changes, as radiators do.
If you make a warm floor in a concrete screed, you can get a system with a large heating ability. But it will slowly respond to temperature control. And even if thermostats are used, the system cannot quickly respond to a change in the external temperature. If weaving pipes are installed in concrete screed, Outdoor heating will give a prominent response to a change in temperature only in two hours. The thermostat quickly responds to the flow of the extraordinary heat and turns off the system, but the heated floor will still give heat for half two hours. This is a lot. The same picture is observed in the opposite case, if you need to turn around the floor, it will be completely warm, it will also be two hours later.
Effective in this case can only be self-regulation. This is a complex dynamic process, during which the heat supply is automatically adjusted. The basis of this process lies two patterns:
Heat spreads from a heated zone to a cold cold;
Value heat flux directly depends on the temperature difference.
Self-regulation with ease can be used both for batteries and for outdoor heating. But at the same time, the radiators are much faster to change the temperature regime, they cooled faster and vice versa, the room is heated. As a result, the resumption of the specified temperature mode takes place faster.
It is not worth overlooking the fact that the peeper of the radiator belief is approximately the same as the heat carrier. In case of outdoor coating This is completely wrong. If the intensive heat from the third-party carrier is income to short "jerks", the heat regulation system in the "warm floor" simply cannot cope with the task. Therefore, the resulting temperature fluctuations arise between the floor and the room as a whole. This problem can be used to be eliminated, but as practice shows, as a result of oscillations remain, only becomes slightly lower.
This can be viewed on the example of a private house heated by warm floors and low-temperature radiators. Suppose four people live in the house, it is equipped with natural ventilation. Foreign heat can come from household appliances and directly people. Comfortable temperature for accommodation is 21 degrees Celsius.
Such a temperature can be maintained in two ways - by moving to night mode or without it.
If I should forget that the operational temperature is an indicator that characterizes the combined revision on the person of different temperatures: radiation and air temperature, as well as the speed of air flow.
As the experiments were shown, they react more quickly to fluctuations in temporators, than ensuring its smaller deviations, it is radiators. The warm floor of them is significantly losing in all respects.
But on this, the positive experience of using radiators does not end. The next argument in their favor is a more efficient and comfortable temperature range indoor.
Back in 2008, Joon Arta Majne and Buildings and Town HolmbeRGA "The distribution of temporatures and a sidelines in a room with a pump heater, outdoor and wall heating was published in the international journal EneRGY AND BUILDINGS. In it, the researchers spent comparative analysis The effectiveness of the use of radiators and warm floors in the heating of rooms with a low-temperature system. The researchers compared the temperature distribution vertically in identical spaces without furniture and humans.
As shown by the result of the experiment, the radiator installed in the subcourse can guarantee a much more uniform distribution of warm air. In addition, it also prevents cold air to the room. But before making a decision on the installation of radiators, it is necessary to take into account the quality of the glass accommodation, the location of furniture and other equally important nuances.
Separately, it should be said about thermal losses. If for the warm floor the percentage of heat loss, depending on the thickness of the heat insulating layer, fluctuates within 5 to 15 percent, then for radiators it is much lower. The high-temperature radiator tolerates heat loss through the rear wall in the amount of 4%, and the low-temperature and is less - only 1%.
It is important when choosing a steel panel radiator right calculationsSo that with the supply of 45 degrees Celsius in the room kept a comfortable target temperature. It is necessary to take into account the thermal insulation of the building, and heat loss, and the predominant temperature "overboard".
The arguments provided at the seminar again confirm the expediency of using low-temperature regulators in heating systems as excellent option Energy savings.
Radiators are traditionally considered attributes of heating systems with high temperature parameters (in the literature The terms "high-temperature" and "radiator" are often even used as synonyms, in particular, when it comes to the contours of heating systems). But postulates, on which such a point of view was based, are outdated. Metal savings and construction insulation are not put today higher energy savings. BUT specifications Modern radiators allow us to speak not only about the possibility of their use in low-temperature systems, but also about the benefits of such a solution. It proves scientific research, for two years, on the initiative of Rettig ICC, the owner of the brands Purmo, Radson, Vogel & Noot, Finimetal, MySon.
If you want to buy heating equipmentYou can go to the corresponding section:
Reducing the temperature of the coolant is the main trend of the development of heating techniques of recent decades in European countries. It became possible as the thermal insulation of buildings, improving the heating devices. In the 1980s, the standard parameters were reduced to 75/65 ºC (feed / "return"). The main benefit from this was the reduction of losses in developing, transporting and distributing heat, as well as greater safety for users.
With increasing popularity of outdoor and other species panel heating In systems where they are used, the feed temperature is reduced to level 55 ºC, which is taken into account by the designers of heat generators, regulating reinforcement, etc.
Today, feed temperature in high-tech systems Heating can be 45 and even 35 ºC. Stimulus to achieve these parameters is the ability to most effectively use such heat sources as thermal pumps and condensing boilers. At the temperature of the coolant of the secondary circuit 55/45 ºC, the COP efficiency coefficient for the soil-water thermal pump is 3.6, and at 35/28 ºC already - 4.6 (when working only on heating). And the operation of boilers in condensation mode, which requires cooling the flue gas flue gases below the "dew point" (when burning liquid fuels - 47 ºC), gives a gain in the efficiency of about 15% or more. Thus, the decrease in the temperature of the coolant provides substantial energy savings, and, accordingly, reducing carbon dioxide emissions into the atmosphere.
Until now, the main solution that enhances the rooms at the low temperature of the coolant, was considered "warm floor" and convectors with copper-aluminum heat exchangers. Initiated Rettig ICC Studies allowed to add steel panel radiators to this series. (However, practice in this case goes ahead of the theory, and such heating devices have long been used as part of low-temperature systems in Sweden .
With the participation of several scientific organizations, including Universities Helsinki and Dresden, radiators were tested under various monitored conditions. The results of other works on the functioning of modern heating systems are introduced to the "evidence-based basis".
At the end of January 2011, research materials are presented to journalists from leading European specialized publications at the seminar held at the Purmo-Radson training center in Erpfendorf (Austria). Professor of Brussels University (VRIJE Universitet Brussels, VUB) Lin Peters and Head of the Department of Energy Systems Institute of Construction Physics. Fraunhofer-Institute for Building Physics, IBP) Dietrich Schmidt.
The report of Lin Peters addressed the thermal comfort, accuracy and speed response of the heating system to change conditions, heat losses.
In particular, it was noted that the causes of local temperature discomfort are: radiation temperature asymmetry (depends on the heat transfer surface and orientation of the heat flux); The temperature of the floor surface (when it comes out of the range from 19 to 27 ºC); The temperature difference vertically (the difference of air temperatures - from the ankle to the head of the standing person - should not exceed 4 ºC).
At the same time, the most comfortable for a person is not static, but "moving" temperature conditions (withdrawal of the University of California, 2003). Interior space with zones having a slight temperature difference increases the sensation of comfort. But large temperature changes are the cause of discomfort.
According to L. Peters, it is radiators that transmit heat as convection and radiation are most suitable for thermal comfort.
Modern buildings are increasingly thermally sensitive - due to the improvement of their thermal insulation. The external and internal thermal perturbations (from sunlight, household appliances, the presence of people) are able to strongly affect the climate in the room. And radiators react to these thermal changes more precisely than the panel heating systems.
As you know, the "warm floor", especially arranged in a concrete screed, is a system with a large heat capacity, slowly reacting to regulatory effects.
Even if the "warm floor" is controlled by thermostats, a quick response to the supply of third-party heat is not possible. When laying heating pipes into a concrete screed, the time of response of outdoor heating to change the amount of incoming heat is about two hours.
A room thermostat quickly reacted to the flow of third-party heat turns off the floor heating, which continues to give heat even about two hours. With the termination of the receipt of third-party heat and the opening thermostatic valve Full germing of the floor is achieved only after the same time. Under these conditions, only the effect of self-regulation is effective.
Self-regulation is a complex dynamic process. In practice, it means that the supply of heat from the heater is regulated by naturally due to the two proper patterns: 1) heat always spreads from a heated zone to a colder; 2) The magnitude of the heat flux is determined by the difference in temperature. It makes it possible to understand the essence of this (it is widely used when choosing heating devices) Equation:
Q \u003d Qual. ∙ (Δt / Δt.) N,
where q is the heat transfer of the heater; ΔT is the difference in temperature of the heater and indoor air; Qual. - heat transfer under nominal conditions; Δt. - difference in the temperature of the heater and air indoors under nominal conditions; n is the heater exhibitor.
Self-regulation is characteristic both for floor heating and radiators. At the same time, for the "warm floor", the value of N is 1.1, and for the radiator - about 1.3 (the exact values \u200b\u200bare given in the catalogs). That is, the response to the change of ΔT in the second case will be more "pronounced", and the restoration of the specified temperature mode will occur faster.
It is important from the point of view of regulation and the fact that the temperature of the radiator surface is approximately equal to the temperature of the coolant, and in the case of the floor heating, it is not so at all.
With short-term intensive income of third-party heat, the heating floor control system does not cope with the work, as a result of which there are fluctuations in the room temperature and gender. Some technical solutions Allow them to reduce, but not eliminate.
On the fig. one Graphs of changes in the operational temperature in modeled conditions of the individual house are shown when it is heated by adjustable highly low-temperature radiators and a "warm floor" ( research L. Peters and Y. van der Venna).
The house is designed to accommodate four people and is equipped with natural ventilation. Sources of third-party heat receipts are people and appliances. Operational temperature is set as a comfortable
21 ºC. The charts consider two options for maintaining it: without transition to energy-saving (night) mode and with it.
We note: the operational temperature is an indicator characterizing the combined effect on the human temperature, radiation temperature and speed of ambient air movement.
The experiments confirmed that the radiators are clearly faster than the "warm floor" react to fluctuations in temperature, providing smaller deviations.
The next argument in favor of radiators, cited at the seminar, is more comfortable and efficient in terms of energy use the temperature profile indoors.
In 2008, John AR Majene and Stur Holmberg published in the international magazine Energy and Buildings work "Distribution of temperature and thermal comfort in a room with a panel radiator, floor and wall heating" (F Low Patterns and Thermal Comfort in A Room With Panel, Floor and Wall Heating). In it, in particular, the vertical temperature distribution is compared in the same area and layout (without furniture and humans), heated by the radiator and the "warm floor" ( fig. 2.). The outdoor temperature was -5 ºC. The multiplicity of air exchange is 0.8.
Etc.) on the unprecedented efficiency of their equipment in modern highly efficient low-temperature heating systems. But no one bothered to explain - where does this efficiency come from?
First, let's consider the question: "Why do low-temperature heating systems need?" They are needed so that modern high-performance thermal energy sources can be used, such as condensation boilers and thermal pumps. Due to the specifics of this equipment, the temperature of the coolant in these systems ranges in the range of 45-55 ° C. Thermal pumps physically cannot raise the temperature of the coolant above. And condensation boilers economically imaginably disperse above the condensation temperature of a steam 55 ° C due to the fact that when this temperature is exceeded, they cease to be condensing and operate as traditional boilers with traditional efficiency of about 90%. In addition, the lower the temperature of the coolant, the longer the polymer pipes will work, because at a temperature of 55 ° C, they degrade 50 years, at a temperature of 75 ° C - 10 years, and at 90 ° C - only three years. In the process of degradation of the pipes become fragile and broken in loaded places.
The temperature of the coolant was determined. What it is lower (in acceptable limits), the more effective energy (gas, electricity) is consumed, and the longer the pipe is working. So, heat from the energy carriers were isolated, the coolant was handed over to the heating device, it was now heat to be transferred from the heating device to the room.
As we all know, heat from the heating devices into the room is in two ways. The first is thermal radiation. The second is the thermal conductivity, turning into convection.
Let's consider every way more closely.
Everyone knows that thermal radiation is the process of heat transfer from a more heated body to a less heated body by means of electromagnetic waves, that is, in fact, it is the transfer of heat by conventional light, only in the infrared range. It is so warm from the Sun reaches the Earth. Due to the fact that thermal radiation is essentially light, then the same physical laws apply to it as for light. Namely: solid bodies and steam practically do not let radiation, and vacuum and air, on the contrary, are transparent for heat rays. And only the presence of concentrated water vapor or dust reduces air transparency for radiation, and part of the radiant energy is absorbed by the medium. Since the air in our homes does not contain a steam or dense dust, it is obvious that it can be considered absolutely transparent for heat rays. That is, radiation is not delayed and is not absorbed by air. Air does not heat radiation.
The radiant heat exchange is as long as there is a difference between the temperatures of radiating and absorbing surfaces.
Now let's talk about thermal conductivity with convection. Thermal conductivity is the transfer of thermal energy from the heated body to the cold body with direct contact. Convection is the type of heat transfer from heated surfaces due to the movement of air created by archimedean power. That is, heated air, becoming easier, under the action of archimedean strength strives upwards, and its place near the heat source occupies cold air. The higher the difference between the temperatures of heated and cold air, the greater the lifting force that pushes the heated air upwards.
In turn, convection interfere with various obstacles, such as window sills, curtains. But the most important thing is that air convection prevents air itself, or rather, its viscosity. And if the air in the scale of the room, the air practically does not interfere with convective streams, then, being "clamped" between the surfaces, it creates a significant resistance to stirring. Remember the window glass. The layer of air between the glasses slows down itself, and we get protection from street cold.
Well, now, when we figured out in the methods of heat transfer and their features, let's look at what processes are in heating devices when different conditions. For high temperatures Heat carrier All heating devices warm equally well - powerful convection, powerful radiation. However, with a decrease in the temperature of the coolant, everything changes.
Convector.Its hottest part is a pipe with a coolant - is inside the heating device. Lamed from her, and the farther from the pipe, the lamels are colder. The temperature of the lamella is almost equal to the ambient temperature. There is no radiation from cold lamellas. Convection at low temperatures interferes with air viscosity. Heat from the convector is extremely small. So that he warms, you need to either increase the temperature of the coolant, which will immediately reduce the efficiency of the system, or blow warm air from it artificially, for example, special fans.
Aluminum (section bimetallic) radiatorstructurally very similar to the convector. Its hottest part is a collector tube with a coolant - is inside the sections of the heating device. Lamed from her, and the farther from the pipe, the lamels are colder. There is no radiation from cold lamellas. Convection at a temperature of 45-55 ° C interferes with air viscosity. As a result, heat from such a "radiator" in normal conditions is extremely small. So that he warms, you need to increase the temperature of the coolant, but is it justified? Thus, we are almost universally faced with the erroneous calculation of the number of sections in aluminum and bimetallic devices, which are based on the selection "on the nominal temperature flow", and not on the basis of real temperature conditions operation.
The hottest part of the steel panel radiator is the outer panel with the coolant - is located outside the heating device. He is warm from her lamellae, and the closer to the center of the radiator, the lamels are colder. And the radiation from the outer panel is always
Steel panel radiator.Its hottest part is the external panel with the coolant - is located outside the heating device. He is warm from her lamellae, and the closer to the center of the radiator, the lamels are colder. Convection at low temperatures interferes with air viscosity. And what about radiation?
The radiation from the outer panel goes until there is a difference between the temperature of the surfaces of the heating device and the surrounding items. That is always.
In addition to the radiator, this useful property Inherent and radiator convectors, such as, for example, Purmo Narbonne. In them, the coolant also flows outside rectangular pipes, And the convective element lamellas are located inside the instrument.
The use of modern energy-efficient heating devices helps to reduce heating costs, and a wide range of sizes panel radiators From leading manufacturers with ease will help embody projects of any complexity.
