Heating network schedule. Temperature graph of coolant supply to the heating system

Looking through the statistics of visits to our blog, I noticed that search phrases such as, for example, very often appear “What should the coolant temperature be at minus 5 outside?”. I decided to post the old one schedule for qualitative regulation of heat supply based on average daily outside air temperature. I would like to warn those who, based on these figures, will try to figure out the relationship with housing departments or heating networks: heating schedules for each individual locality are different (I wrote about this in the article). They work according to this schedule heating network in Ufa (Bashkiria).

I also want to draw attention to the fact that regulation occurs according to average daily outside air temperature, so if, for example, outside at night minus 15 degrees, and during the day minus 5, then the coolant temperature will be maintained in accordance with the schedule at minus 10 o C.

Typically, the following temperature charts are used: 150/70 , 130/70 , 115/70 , 105/70 , 95/70 . The schedule is selected depending on specific local conditions. House heating systems operate according to schedules 105/70 and 95/70. Main heating networks operate according to schedules 150, 130 and 115/70.

Let's look at an example of how to use a chart. Let's say the temperature outside is minus 10 degrees. Heating networks operate according to a temperature schedule 130/70 , which means when -10 o C the temperature of the coolant in the supply pipeline of the heating network should be 85,6 degrees, in the supply pipe of the heating system - 70.8 o C with a 105/70 schedule or 65.3 o C with a 95/70 schedule. The water temperature after the heating system should be 51,7 about S.

As a rule, the temperature values ​​in the supply pipeline of heating networks are rounded when assigned to a heat source. For example, according to the schedule it should be 85.6 o C, but at a thermal power plant or boiler house it is set to 87 degrees.

Temperature outdoor air Tnv, o S	Temperature of network water in the supply pipeline T1, o C			Water temperature in the heating system supply pipe T3, o C		Water temperature after the heating system T2, o C
	150	130	115	105	95
8	53,2	50,2	46,4	43,4	41,2	35,8
7	55,7	52,3	48,2	45,0	42,7	36,8
6	58,1	54,4	50,0	46,6	44,1	37,7
5	60,5	56,5	51,8	48,2	45,5	38,7
4	62,9	58,5	53,5	49,8	46,9	39,6
3	65,3	60,5	55,3	51,4	48,3	40,6
2	67,7	62,6	57,0	52,9	49,7	41,5
1	70,0	64,5	58,8	54,5	51,0	42,4
0	72,4	66,5	60,5	56,0	52,4	43,3
-1	74,7	68,5	62,2	57,5	53,7	44,2
-2	77,0	70,4	63,8	59,0	55,0	45,0
-3	79,3	72,4	65,5	60,5	56,3	45,9
-4	81,6	74,3	67,2	62,0	57,6	46,7
-5	83,9	76,2	68,8	63,5	58,9	47,6
-6	86,2	78,1	70,4	65,0	60,2	48,4
-7	88,5	80,0	72,1	66,4	61,5	49,2
-8	90,8	81,9	73,7	67,9	62,8	50,1
-9	93,0	83,8	75,3	69,3	64,0	50,9
-10	95,3	85,6	76,9	70,8	65,3	51,7
-11	97,6	87,5	78,5	72,2	66,6	52,5
-12	99,8	89,3	80,1	73,6	67,8	53,3
-13	102,0	91,2	81,7	75,0	69,0	54,0
-14	104,3	93,0	83,3	76,4	70,3	54,8
-15	106,5	94,8	84,8	77,9	71,5	55,6
-16	108,7	96,6	86,4	79,3	72,7	56,3
-17	110,9	98,4	87,9	80,7	73,9	57,1
-18	113,1	100,2	89,5	82,0	75,1	57,9
-19	115,3	102,0	91,0	83,4	76,3	58,6
-20	117,5	103,8	92,6	84,8	77,5	59,4
-21	119,7	105,6	94,1	86,2	78,7	60,1
-22	121,9	107,4	95,6	87,6	79,9	60,8
-23	124,1	109,2	97,1	88,9	81,1	61,6
-24	126,3	110,9	98,6	90,3	82,3	62,3
-25	128,5	112,7	100,2	91,6	83,5	63,0
-26	130,6	114,4	101,7	93,0	84,6	63,7
-27	132,8	116,2	103,2	94,3	85,8	64,4
-28	135,0	117,9	104,7	95,7	87,0	65,1
-29	137,1	119,7	106,1	97,0	88,1	65,8
-30	139,3	121,4	107,6	98,4	89,3	66,5
-31	141,4	123,1	109,1	99,7	90,4	67,2
-32	143,6	124,9	110,6	101,0	94,6	67,9
-33	145,7	126,6	112,1	102,4	92,7	68,6
-34	147,9	128,3	113,5	103,7	93,9	69,3
-35	150,0	130,0	115,0	105,0	95,0	70,0

Please do not rely on the diagram at the beginning of the post - it does not correspond to the data from the table.

Temperature graph calculation

The method for calculating the temperature graph is described in the reference book (Chapter 4, paragraph 4.4, p. 153).

This is a rather labor-intensive and time-consuming process, since for each outdoor temperature you need to count several values: T 1, T 3, T 2, etc.

To our joy, we have a computer and a spreadsheet processor MS Excel. A work colleague shared with me a ready-made table for calculating the temperature graph. It was made at one time by his wife, who worked as an engineer for a group of modes in thermal networks.

In order for Excel to calculate and build a graph, you just need to enter a few initial values:

• design temperature in the supply pipeline of the heating network T 1
• design temperature in the return pipeline of the heating network T 2
• design temperature in the heating system supply pipe T 3
• Outdoor temperature T n.v.
• Indoor temperature T v.p.
• coefficient " n"(it is, as a rule, unchanged and equal to 0.25)
• Minimum and maximum cut of the temperature graph Cut min, Cut max.

All. nothing more is required from you. The calculation results will be in the first table of the sheet. It is highlighted with a bold frame.

The charts will also adjust to the new values.

The table also calculates the temperature of direct network water taking into account wind speed.

Each management company strives to achieve economical heating costs apartment building. In addition, residents of private houses are trying to come. This can be achieved by drawing up a temperature graph that reflects the dependence of the heat produced by the carriers on the weather conditions outside. Proper Use This data allows you to optimally distribute hot water and heating to consumers.

What is a temperature graph

The coolant should not maintain the same operating mode, because outside the apartment the temperature changes. This is what you need to be guided by and, depending on it, change the temperature of the water in heating objects. The dependence of the coolant temperature on the outside air temperature is compiled by technologists. To compile it, the values ​​​​available for the coolant and the outside air temperature are taken into account.

During the design of any building, the size of the heat-providing equipment installed in it, the dimensions of the building itself and the cross-sections available in the pipes must be taken into account. IN high-rise building Residents cannot independently increase or decrease the temperature, since it is supplied from the boiler room. Adjustment of the operating mode is always carried out taking into account the temperature curve of the coolant. The temperature scheme itself is also taken into account - if the return pipe supplies water with a temperature above 70°C, then the coolant flow will be excessive, but if it is significantly lower, there will be a deficiency.

Important! The temperature schedule is drawn up in such a way that at any outside air temperature in the apartments a stable optimal heating level is maintained at 22 °C. Thanks to it, even the most severe frosts are not scary, because the heating systems will be ready for them. If it is -15 °C outside, then it is enough to track the value of the indicator to find out what the temperature of the water in the heating system will be at that moment. The harsher the weather outside, the hotter the water inside the system should be.

But the level of heating maintained indoors depends not only on the coolant:

• Outside temperature;
• The presence and strength of wind - its strong gusts significantly affect heat loss;
• Thermal insulation - high-quality structural parts of the building help to retain heat in the building. This is done not only during the construction of the house, but also separately at the request of the owners.

Table of coolant temperature versus outside air temperature

In order to calculate the optimal temperature regime, you need to take into account the characteristics of heating devices - batteries and radiators. The most important thing is to calculate their specific power; it will be expressed in W/cm2. This will most directly affect the transfer of heat from the heated water to the heated air in the room. It is important to take into account their surface power and the drag coefficient available window openings and external walls.

After all the values ​​have been taken into account, you need to calculate the difference between the temperature in two pipes - at the entrance to the house and at the exit from it. The higher the value in the input pipe, the higher the value in the return pipe. Accordingly, indoor heating will increase under these values.

Weather outside, C	at the entrance to the building, C	Return pipe, C
+10	30	25
+5	44	37
0	57	46
-5	70	54
-10	83	62
-15	95	70

Proper use of coolant involves attempts by house residents to reduce the temperature difference between the inlet and outlet pipes. This could be construction work to insulate a wall from the outside or thermal insulation of external heat supply pipes, insulation of floors above a cold garage or basement, insulation of the inside of a house, or several works performed simultaneously.

Heating in the radiator must also comply with the standards. In central heating systems it usually varies from 70 C to 90 C depending on the outside air temperature. It is important to consider that in corner rooms the temperature cannot be less than 20 C, although in other rooms of the apartment a decrease to 18 C is allowed. If the temperature outside drops to -30 C, then the heating in the rooms should rise by 2 C. In other rooms it should also the temperature increases, provided that it can be different in rooms for different purposes. If there is a child in the room, then it can vary from 18 C to 23 C. In storerooms and corridors, heating can vary from 12 C to 18 C.

It is important to note! The average daily temperature is taken into account - if the temperature at night is about -15 C, and during the day - -5 C, then it will be calculated according to the value of -10 C. If at night it was about -5 C, and in the daytime it rose to +5 C, then heating is taken into account at the value of 0 C.

Schedule for hot water supply to the apartment

In order to deliver optimal hot water to the consumer, CHP plants must send it as hot as possible. Heating lines are always so long that their length can be measured in kilometers, and the length of apartments is measured in thousands of square meters. Whatever the insulation of the pipes, heat is lost on the way to the user. Therefore, it is necessary to heat the water as much as possible.


However, water cannot be heated above its boiling point. Therefore, a solution was found - to increase the pressure.

It is important to know! As it increases, the boiling point of water shifts upward. As a result, it reaches the consumer really hot. When the pressure increases, risers, mixers and taps do not suffer, and all apartments up to the 16th floor can be provided with hot water supply without additional pumps. In a heating main, water usually contains 7-8 atmospheres, the upper limit is usually 150 with a margin.

It looks like this:

Boiling temperature	Pressure
100	1
110	1,5
119	2
127	2,5
132	3
142	4
151	5
158	6
164	7
169	8

Innings hot water V winter time year must be continuous. Exceptions to this rule include heat supply accidents. The hot water supply can only be turned off in the summer for preventive maintenance. Such work is carried out both in heat supply systems closed type, and in open systems.

After installing the heating system, it is necessary to adjust the temperature regime. This procedure must be carried out according to existing standards.

Temperature standards

Requirements for coolant temperature are set out in regulatory documents that establish the design, installation and use of engineering systems of residential and public buildings. They are described in the State Building Codes and Rules:

• DBN (V. 2.5-39 Heat networks);
• SNiP 2.04.05 “Heating, ventilation and air conditioning.”

For the calculated supply water temperature, the figure is taken that is equal to the water temperature at the outlet of the boiler, according to its passport data.

For individual heating deciding what the coolant temperature should be should take into account the following factors:

• 1Start and end of the heating season based on the average daily outdoor temperature of +8 °C for 3 days;
• 2The average temperature inside heated premises of housing, communal and public importance should be 20 °C, and for industrial buildings 16°C;
• 3The average design temperature must comply with the requirements of DBN V.2.2-10, DBN V.2.2.-4, DSanPiN 5.5.2.008, SP No. 3231-85. According to SNiP 2.04.05 “Heating, ventilation and air conditioning” (clause 3.20) limit values coolant are:
• 1
  For a hospital - 85 °C (excluding psychiatric and drug departments, as well as administrative or domestic premises);
• 2For residential, public, and domestic buildings (not counting halls for sports, trade, spectators and passengers) – 90 °C;
• 3For auditoriums, restaurants and premises for production of categories A and B – 105 °C;
• 4For catering establishments (excluding restaurants) – this is 115 °C;
• 5For production premises (category B, D and D), where flammable dust and aerosols are emitted – 130 °C;
• 6For staircases, lobbies, pedestrian crossings, technical premises, residential buildings, production premises without the presence of flammable dust and aerosols - 150 ° C. Depending on external factors, the temperature of the water in the heating system can be from 30 to 90 ° C. When heated above 90 °C, dust and paintwork begin to decompose. For these reasons, sanitary standards prohibit greater heating.

  For calculation optimal performance Special graphs and tables can be used that define the norms depending on the season:

  • With an average reading outside the window of 0 °C, the supply for radiators with different wiring is set at 40 to 45 °C, and the return temperature at 35 to 38 °C;
  • At -20 °C, the supply is heated from 67 to 77 °C, and the return rate should be from 53 to 55 °C;
  • At -40 °C outside the window, all heating devices are set to the maximum permissible values. On the supply side it is from 95 to 105 °C, and on the return side it is 70 °C.

  Optimal values ​​in an individual heating system

  

  Autonomous heating helps to avoid many problems that arise with a centralized network, and the optimal temperature of the coolant can be adjusted according to the season. In the case of individual heating, the concept of standards includes the heat transfer of a heating device per unit area of ​​​​the room where this device is located. The thermal regime in this situation is ensured design features heating devices.

  It is important to ensure that the coolant in the network does not cool below 70 °C. The optimal temperature is considered to be 80 °C. With a gas boiler, it is easier to control heating, because manufacturers limit the ability to heat the coolant to 90 °C. Using sensors to regulate the gas supply, the heating of the coolant can be adjusted.

  It is a little more difficult with solid fuel devices; they do not regulate the heating of the liquid, and can easily turn it into steam. And it is impossible to reduce the heat from coal or wood by turning the knob in such a situation. Control of heating of the coolant is quite conditional with high errors and is carried out by rotary thermostats and mechanical dampers.

  Electric boilers allow you to smoothly regulate the heating of the coolant from 30 to 90 °C. They are equipped with an excellent overheat protection system.

  Single-pipe and double-pipe lines

  The design features of a one-pipe and two-pipe heating network determine different standards for heating the coolant.

  For example, for a single-pipe main the maximum norm is 105 °C, and for a two-pipe main it is 95 °C, while the difference between the return and supply should be respectively: 105 - 70 °C and 95 - 70 °C.

  Coordination of coolant and boiler temperatures

  

  Regulators help coordinate the temperature of the coolant and the boiler. These are devices that create automatic control and adjustment of return and supply temperatures.

  The return temperature depends on the amount of liquid passing through it. Regulators cover the liquid supply and increase the difference between the return and supply to the level required, and the necessary indicators are installed on the sensor.

  If the flow needs to be increased, a boost pump can be added to the network, which is controlled by a regulator. To reduce the heating of the supply, a “cold start” is used: that part of the liquid that has passed through the network is again transported from the return to the inlet.

  The regulator redistributes the supply and return flows according to the data collected by the sensor, and ensures strict temperature standards for the heating network.

  Ways to reduce heat loss

  

  The above information will help to be used for correct calculation coolant temperature standards and will tell you how to determine situations when you need to use a regulator.

  But it is important to remember that the temperature in the room is affected not only by the temperature of the coolant, street air and wind strength. The degree of insulation of the facade, doors and windows in the house should also be taken into account.

  To reduce heat loss from your home, you need to worry about its maximum thermal insulation. Insulated walls, sealed doors, and metal-plastic windows will help reduce heat loss. This will also reduce heating costs.

  Norms and optimal values ​​of coolant temperature, House repair and construction

  
  After installing the heating system, it is necessary to adjust the temperature regime. This procedure must be carried out in accordance with existing standards. Norms

Coolant for heating systems, coolant temperature, standards and parameters

In Russia, heating systems that operate using liquid coolants are more popular. This is most likely due to the fact that in many regions of the country the climate is quite harsh. Liquid heating systems are a set of equipment that includes components such as: pumping stations, boiler rooms, pipelines, heat exchangers. How efficiently and properly the entire system will work depends largely on the characteristics of the coolant. Now the question arises, which coolant for heating systems to use for operation.

Coolant for heating systems

Coolant requirements

You need to immediately understand that there is no ideal coolant. Those types of coolants that exist today can perform their functions only in a certain temperature range. If you go beyond this range, the quality characteristics of the coolant can change dramatically.

The heating fluid must have properties that will allow it to transfer as much heat as possible in a certain unit of time. The viscosity of the coolant largely determines what effect it will have on pumping the coolant throughout the heating system over a specific time interval. The higher the viscosity of the coolant, the more good characteristics he has.

Physical properties of coolants

The coolant should not have a corrosive effect on the material from which pipes or heating devices are made.

If this condition is not met, the choice of materials will become more limited. In addition to the above properties, the coolant must also have lubricating abilities. The choice of materials used for the construction of various mechanisms and circulation pumps depends on these characteristics.

In addition, the coolant must be safe based on such characteristics as: ignition temperature, release of toxic substances, flash of vapors. Also, the coolant should not be too expensive; by studying the reviews, you can understand that even if the system works efficiently, it will not justify itself from a financial point of view.

Water as a coolant

Water can serve as a coolant liquid necessary for the operation of a heating system. Of those liquids that exist on our planet in their natural state, water has the highest heat capacity - about 1 kcal. In simpler terms, if 1 liter of water is heated to a heating system coolant temperature of +90 degrees, and the water is cooled to 70 degrees using a heating radiator, then the room heated by this radiator will receive about 20 kcal of heat.

Water also has a fairly high density - 917 kg/1 sq. meter. The density of water can change when it is heated or cooled. Only water has properties such as expansion when heated or cooled.

Water is the most popular and accessible coolant

Water is also superior to many synthetic coolant fluids in terms of toxicity and environmental friendliness. If suddenly such a coolant leaks from the heating system somehow, this will not create any situations that will cause health problems for the residents of the house. You only need to be wary of hot water getting directly onto the human body. Even if a coolant leak occurs, the volume of coolant in the heating system can very easily be restored. All you need to do is add the required amount of water through expansion tank heating systems with natural circulation. If we judge the price category, then it is simply impossible to find a coolant that will cost less than water.

Despite the fact that a coolant such as water has many advantages, it also has some disadvantages.

In its natural state, water contains various salts and oxygen, which can adversely affect the internal condition of the components and parts of the heating system. Salt can have a corrosive effect on materials, and will also cause scale to build up on the internal walls of pipes and elements of the heating system.

Chemical composition of water in different regions Russia

This shortcoming can be eliminated. The simplest method that can be used to soften water is boiling. When boiling water, care must be taken to ensure that this thermal process occurs in a metal container, and that the container is not covered with a lid. After such heat treatment, a significant part of the salts will settle to the bottom of the container, and carbon dioxide will be completely removed from the water.

A larger amount of salts can be removed if you use a container with a large bottom for boiling. Salt deposits will be easily visible at the bottom of the vessel and will look like scale. This method of eliminating salts is not 100% effective, since only less stable calcium and magnesium bicarbonates are removed from the water, but more stable compounds of such elements remain in the water.

There is another way to remove salts from water - this is a reagent or chemical method. Using this method, it is possible to convert salts that are contained in water even in an insoluble state.

To carry out such water treatment, the following components will be required: slaked lime, soda ash or sodium orthophosphate. If you fill the heating system with coolant and add the first two of the listed reagents to the water, this will cause the formation of a precipitate of calcium and magnesium orthophosphates. And if you add the third of the listed reagents to water, a carbonate precipitate forms. After chemical reaction is completely completed, the sediment can be removed through a method such as water filtration. Sodium orthophosphate is a reagent that will help soften water. Important point, which must be taken into account when choosing this reagent, is the correct flow of coolant in the heating system for a certain volume of water.

Installation for chemical water softening

It is best to use distilled water for heating systems, as it does not contain harmful impurities. True, distilled water is more expensive than regular water. One liter of distilled water will cost approximately 14 Russian rubles. Before filling the heating system with distilled coolant, it is necessary to thoroughly rinse all heating devices, boiler and pipes with plain water. Even if the heating system was installed not long ago and has not been used before, its components still need to be washed, since contamination will occur in any case.

In order to flush the system, you can also use melt water, since such water contains almost no salts. Even artesian or well water contains more salts than melt or rain water.

The water in the heating system is frozen

Studying the parameters of the heating system coolant, it can be noted that another big disadvantage of water as a heating system coolant is that it will freeze if the water temperature drops below 0 degrees. When water freezes, it expands, and this will lead to breakdown of heating devices or damage to pipes. Such a threat can only arise if there are interruptions in the heating system and the water stops heating. This type of coolant is also not recommended for use in those houses where the residence is not permanent, but periodic.

Antifreeze as a coolant

Antifreeze for heating systems

Higher performance for efficient work The heating system has a type of coolant such as antifreeze. By pouring antifreeze into the heating system circuit, you can reduce the risk of the heating system freezing during the cold season to a minimum. Antifreeze is designed for lower temperatures than water, and they are not able to change its physical state. Antifreeze has many advantages, since it does not cause scale deposits and does not contribute to corrosive wear of the internal area of ​​the heating system elements.

Even if antifreeze hardens at very low temperatures, it will not expand like water, and this will not cause any damage to heating system components. If it freezes, the antifreeze will turn into a gel-like composition, and the volume will remain the same. If, after freezing, the temperature of the coolant in the heating system increases, it will go from a gel-like state to a liquid state, and this will not cause any negative consequences for the heating circuit.

Many manufacturers add various additives to antifreeze that can increase the service life of the heating system.

Such additives help remove various deposits and scale from heating system elements, and also eliminate pockets of corrosion. When choosing antifreeze, you need to remember that such a coolant is not universal. The additives it contains are only suitable for certain materials.

Existing coolants for heating systems-antifreeze can be divided into two categories based on their freezing point. Some are designed for temperatures down to -6 degrees, and others up to -35 degrees.

Properties various types antifreeze

The composition of a coolant such as antifreeze is designed for a full five years of operation, or 10 heating seasons. The calculation of the coolant in the heating system must be accurate.

Antifreeze also has its disadvantages:

• The heat capacity of antifreeze is 15% lower than that of water, which means they will release heat more slowly;
• They have a fairly high viscosity, which means that a fairly powerful one will need to be installed in the system. circulation pump.
• When heated, antifreeze increases in volume more than water, which means that the heating system must include a closed expansion tank, and radiators must have a larger capacity than those used to organize a heating system in which water is the coolant.
• The speed of the coolant in the heating system - that is, the fluidity of antifreeze is 50% greater than that of water, which means that all connecting connectors of the heating system must be very carefully sealed.
• Antifreeze, which includes ethylene glycol, is toxic to humans, so it can only be used for single-circuit boilers.

When using a type of coolant such as antifreeze in a heating system, certain conditions must be taken into account:

• The system must be supplemented with a circulation pump with powerful parameters. If the circulation of coolant in the heating system and the heating circuit is long, then the circulation pump must be installed externally.
• Volume expansion tank should be no less than twice that of a tank used for a coolant such as water.
• It is necessary to install volumetric radiators and pipes with a large diameter in the heating system.
• It is prohibited to use automatic type air vents. For a heating system in which antifreeze is the coolant, only taps can be used manual type. A more popular manual type crane is the Mayevsky crane.
• If antifreeze is diluted, then only with distilled water. Melt, rain or well water will not work.
• Before filling the heating system with coolant - antifreeze, it must be thoroughly rinsed with water, not forgetting about the boiler. Manufacturers of antifreeze recommend changing them in the heating system at least once every three years.
• If the boiler is cold, it is not recommended to immediately set high coolant temperature standards for the heating system. It should rise gradually, the coolant needs some time to heat up.

If in winter a double-circuit boiler running on antifreeze is turned off for a long period, then it is necessary to drain the water from the hot water supply circuit. If water freezes, it can expand and cause damage to pipes or other heating system components.

Coolant for heating systems, coolant temperature, standards and parameters

In Russia, heating systems that operate using liquid coolants are more popular. This is most likely due to the fact that in many regions of the country the climate is quite harsh. Liquid heating systems are a set of equipment that includes such

Standard coolant temperature in the heating system

Providing comfortable living conditions during the cold season is the task of heat supply. It is interesting to see how a person tried to warm his home. Initially, the huts were heated in a black way, the smoke escaping into a hole in the roof.

Later we moved on to stove heating, then, with the advent of boilers, to water. Boiler plants increased their capacity: from a boiler room in one house to a district boiler room. And finally, with the increase in the number of consumers with the growth of cities, people came to centralized heating from thermal power plants.

Depending on the source of heat energy, there are centralized And decentralized heat supply systems. The first type includes heat production based on the combined production of electricity and heat at thermal power plants and heat supply from district heating boiler houses.

Decentralized heat supply systems include small-capacity boiler plants and individual boilers.

Based on the type of coolant, heating systems are divided into steam And water.

Advantages of water heating systems:

• the ability to transport coolant over long distances;
• the possibility of centralized regulation of heat supply in the heating network by changing the hydraulic or temperature regime;
• no loss of steam and condensate, which always occurs in steam systems.

Formula for calculating heat supply

The coolant temperature, depending on the outside temperature, is maintained by the heat supply organization based on the temperature schedule.

The temperature schedule of heat supply to the heating system is based on monitoring air temperatures during the heating period. In this case, the eight coldest winters in fifty years are selected. The strength and speed of wind in different geographical areas is taken into account. The necessary heat loads to heat the room to 20-22 degrees are calculated. Industrial premises have their own coolant parameters to support technological processes.

The heat balance equation is compiled. Thermal loads of consumers are calculated taking into account heat losses in environment, the corresponding heat supply is calculated to cover the total thermal loads. The colder it is outside, the higher the losses to the environment, the more heat is released from the boiler room.

Heat release is calculated using the formula:

Q= Gsv * C * (tpr-tb), where

• Q - heat load in kW, the amount of heat supplied per unit of time;
• Gsv - coolant flow rate in kg/sec;
• tpr and tb - temperatures in the forward and return pipelines depending on the outside air temperature;
• C is the heat capacity of water in kJ/ (kg*deg).

Parameter control methods

Three methods are used to regulate the heat load:

With the quantitative method, the heat load is regulated by changing the amount of coolant supplied. With the help of heating network pumps, the pressure in the pipelines increases, and heat output increases with increasing coolant flow rate.

The qualitative method consists of increasing the parameters of the coolant at the outlet of the boilers while maintaining the flow rate. This method is most often used in practice.

With the quantitative-qualitative method, the parameters and flow rate of the coolant are changed.

Factors affecting room heating during the heating season:

Heat supply systems are divided depending on the design into single-pipe and two-pipe. For each design, its own thermal schedule in the supply pipeline is approved. For single pipe heating system Maximum temperature in the supply line 105 degrees, in the two-pipe - 95 degrees. The difference in supply and return temperatures in the first case is regulated in the range of 105−70, for a two-pipe system - in the range of 95−70 degrees.

Choosing a heating system for a private home

The operating principle of a single-pipe heating system is to supply coolant to the upper floors; all radiators are connected to the downward pipeline. It is clear that it will be warmer on the upper floors than on the lower ones. Because a private house at best, it has two or three floors, the contrast in heating the premises does not threaten. And in a one-story building there will generally be uniform heating.

What are the advantages of such a heat supply system:

The disadvantages of the design are high hydraulic resistance, the need to turn off the heating of the entire house during repairs, restrictions on connecting heating devices, the impossibility of regulating the temperature in a single room, and high heat losses.

For improvement, it was proposed to use a bypass system.

Bypass- a section of pipe between the supply and return pipelines, a workaround in addition to the radiator. They are equipped with valves or taps and allow you to regulate the temperature in the room or completely turn off a separate battery.

A single-pipe heating system can be vertical or horizontal. In both cases, air pockets appear in the system. The system inlet temperature is maintained at a high temperature to warm all rooms, so the piping system must withstand high pressure water.

Two-pipe heating system

The principle of operation is to connect each heating device to the supply and return pipelines. The cooled coolant is sent through the return pipeline to the boiler.

Additional investments will be required during installation, but there will be no air pockets in the system.

Temperature standards for premises

In a residential building, the temperature in the corner rooms should not be lower than 20 degrees, for interior spaces The standard is 18 degrees, for showers - 25 degrees. When the outside air temperature drops to -30 degrees, the standard rises to 20−22 degrees, respectively.

Specific standards have been established for premises where children are located. The main range is from 18 to 23 degrees. Moreover, for premises for different purposes the indicator varies.

At school, the temperature should not fall below 21 degrees, for bedrooms in boarding schools it is allowed not lower than 16 degrees, in the swimming pool - 30 degrees, on the verandas of kindergartens intended for walking - not lower than 12 degrees, for libraries - 18 degrees, in cultural in public institutions the temperature is 16−21 degrees.

When developing standards for different rooms, it is taken into account how much time a person spends in movement, so for gyms the temperature will be lower than in classrooms.

The building codes and regulations of the Russian Federation SNiP 41−01−2003 “Heating, ventilation and air conditioning” have been approved, regulating the air temperature depending on the purpose, number of floors, and height of the premises. For an apartment building, the maximum temperature of the coolant in the battery for a one-pipe system is 105 degrees, for a two-pipe system 95 degrees.

In the heating system of a private house

The optimal temperature in an individual heating system is 80 degrees. It is necessary to ensure that the coolant level does not drop below 70 degrees. WITH gas boilers It is easier to regulate the thermal regime. Boilers work completely differently solid fuel. In this case, water can very easily turn into steam.

Electric boilers allow you to easily regulate the temperature in the range from 30−90 degrees.

Possible interruptions in heat supply

1. If the room temperature is 12 degrees, it is allowed to turn off the heat for 24 hours.
2. In the temperature range from 10 to 12 degrees, the heat is turned off for a maximum of 8 hours.
3. When the room temperature is below 8 degrees, it is not allowed to turn off the heating for more than 4 hours.

Regulating the temperature of the coolant in the heating system: methods, dependence factors, norms of indicators

Classification and advantages of coolants. What does the temperature in the heating network depend on? Which heating system to choose for an individual building. Standards for water temperature in the heating network.

The supply of heat to a room is associated with a simple temperature schedule. The temperature values ​​of the water supplied from the boiler room do not change in the room. They have standard values ​​and range from +70ºС to +95ºС. This temperature schedule for the heating system is the most popular.

Adjusting the air temperature in the house

Not everywhere in the country there is centralized heating, so many residents install independent systems. Their temperature graph differs from the first option. In this case, temperature indicators are significantly reduced. They depend on the efficiency of modern heating boilers.

If the temperature reaches +35ºС, the boiler will operate at maximum power. It depends on the heating element, where thermal energy can be picked up by exhaust gases. If the temperature values ​​are greater than + 70 ºС, then the boiler performance drops. In that case, in his technical specifications efficiency is indicated at 100%.

Temperature schedule and its calculation

What the graph will look like depends on the outside temperature. The more negative meaning outside temperature, the greater the heat loss. Many people do not know where to get this indicator. This temperature is prescribed in regulatory documents. The temperature of the coldest five-day period is taken as the calculated value, and the lowest value over the last 50 years is taken.

Graph of the dependence of external and internal temperatures

The graph shows the relationship between external and internal temperatures. Let's say the outside temperature is -17ºС. Drawing a line upward until it intersects with t2, we obtain a point characterizing the temperature of the water in the heating system.

Thanks to the temperature schedule, you can prepare the heating system even for the most severe conditions. It also reduces material costs for installing a heating system. If we consider this factor from the point of view of mass construction, the savings are significant.

• Outside air temperature. The smaller it is, the more negatively it affects heating;
• Wind. When strong wind occurs, heat loss increases;
• The temperature inside the room depends on the thermal insulation of the structural elements of the building.

Over the past 5 years, construction principles have changed. Builders increase the value of a home by insulating elements. As a rule, this applies to basements, roofs, and foundations. These expensive measures subsequently allow residents to save on the heating system.

Heating temperature chart

The graph shows the dependence of the temperature of external and internal air. The lower the outside air temperature, the higher the coolant temperature in the system will be.

A temperature schedule is developed for each city during the heating season. In small settlements, a boiler room temperature schedule is drawn up, which ensures required amount coolant to the consumer.

• quantitative - characterized by a change in the flow rate of coolant supplied to the heating system;
• qualitative - consists of regulating the temperature of the coolant before supplying it to the premises;
• temporary - a discrete method of supplying water to the system.

The temperature schedule is a schedule of heating pipes that distributes the heating load and is regulated using centralized systems. There is also an elevated schedule, it is created for closed system heating, that is, to ensure the supply of hot coolant to connected objects. When using open system it is necessary to adjust the temperature schedule, since the coolant is consumed not only for heating, but also for domestic water consumption.

The temperature graph is calculated using simple method. Hto build it, necessary initial temperature air data:

• external;
• in room;
• in the supply and return pipelines;
• at the exit of the building.

In addition, you should know the nominal thermal load. All other coefficients are standardized by reference documentation. The system is calculated for any temperature schedule, depending on the purpose of the room. For example, for large industrial and civil facilities a schedule of 150/70, 130/70, 115/70 is drawn up. For residential buildings this figure is 105/70 and 95/70. The first indicator shows the supply temperature, and the second - the return temperature. The calculation results are entered into a special table, which shows the temperature at certain points of the heating system, depending on the outside air temperature.

The main factor in calculating the temperature schedule is the outside air temperature. The calculation table must be drawn up so that the maximum values ​​of the coolant temperature in the heating system (graph 95/70) ensure heating of the room. Room temperatures are prescribed by regulatory documents.

Temperature heating devices

The main indicator is the temperature of heating devices. The ideal temperature schedule for heating is 90/70ºС. It is impossible to achieve such an indicator, since the temperature inside the room should not be the same. It is determined depending on the purpose of the room.

In accordance with the standards, the temperature in the corner living room is +20ºС, in the rest – +18ºС; in the bathroom – +25ºС. If the outside air temperature is -30ºС, then the indicators increase by 2ºС.

• in rooms where children are located – +18ºС to +23ºС;
• children's educational institutions – +21ºС;
• in cultural institutions with mass attendance – +16ºС to +21ºС.

This range of temperature values ​​is compiled for all types of premises. It depends on the movements performed inside the room: the more there are, the lower the air temperature. For example, in sports facilities people move a lot, so the temperature is only +18ºС.

Room temperature

• Outside air temperature;
• Type of heating system and temperature difference: for a single-pipe system – +105ºС, and for a single-pipe system – +95ºС. Accordingly, the differences in for the first region are 105/70ºС, and for the second – 95/70ºС;
• Direction of coolant supply to heating devices. With the top feed, the difference should be 2 ºС, with the bottom – 3 ºС;
• Type of heating devices: heat transfer is different, so the temperature curve will be different.

First of all, the coolant temperature depends on the outside air. For example, the temperature outside is 0ºC. In this case, the temperature regime in the radiators should be 40-45ºC at the supply, and 38ºC at the return. When the air temperature is below zero, for example -20ºС, these indicators change. In this case, the supply temperature becomes 77/55ºС. If the temperature reaches -40ºС, then the indicators become standard, that is, +95/105ºС at the supply, and +70ºС at the return.

Additional options

In order for a certain temperature of the coolant to reach the consumer, it is necessary to monitor the condition of the outside air. For example, if it is -40ºС, the boiler room should supply hot water with an indicator of +130ºС. Along the way, the coolant loses heat, but the temperature still remains high when it enters the apartments. The optimal value is +95ºС. To do this, an elevator unit is installed in the basements, which serves to mix hot water from the boiler room and coolant from the return pipeline.

Several institutions are responsible for the heating main. The boiler room monitors the supply of hot coolant to the heating system, and the condition of the pipelines is monitored by city heating networks. The housing office is responsible for the elevator element. Therefore, in order to solve the problem of coolant supply to new house, you need to contact different offices.

Installation of heating devices is carried out in accordance with regulatory documents. If the owner himself replaces the battery, then he is responsible for the operation of the heating system and changes in temperature conditions.

Adjustment methods

If the boiler room is responsible for the parameters of the coolant leaving the warm point, then the housing office workers must be responsible for the temperature inside the room. Many residents complain about the cold in their apartments. This occurs due to a deviation in the temperature graph. In rare cases, it happens that the temperature rises by a certain value.

Heating parameters can be adjusted in three ways:

• Reaming the nozzle.

If the supply and return coolant temperatures are significantly underestimated, then it is necessary to increase the diameter of the elevator nozzle. This way, more liquid will pass through it.

How to do this? To begin with, shut-off valves are closed (house valves and taps at the elevator unit). Next, the elevator and nozzle are removed. Then it is drilled out by 0.5-2 mm, depending on how much it is necessary to increase the temperature of the coolant. After these procedures, the elevator is mounted in its original place and put into operation.

To ensure sufficient tightness of the flange connection, it is necessary to replace the paronite gaskets with rubber ones.

• Silence the suction.

In severe cold weather, when the problem of freezing of the heating system in the apartment arises, the nozzle can be completely removed. In this case, the suction may become a jumper. To do this, you need to plug it with a steel pancake 1 mm thick. This process is carried out only in critical situations, since the temperature in pipelines and heating devices will reach 130ºC.

In the middle of the heating season, a significant increase in temperature may occur. Therefore, it is necessary to regulate it using a special valve on the elevator. To do this, the supply of hot coolant is switched to the supply pipeline. A pressure gauge is mounted on the return line. Adjustment occurs by closing the valve on the supply pipeline. Next, the valve opens slightly, and the pressure should be monitored using a pressure gauge. If you simply open it, the cheeks will sag. That is, an increase in pressure drop occurs in the return pipeline. Every day the indicator increases by 0.2 atmospheres, and the temperature in the heating system must be constantly monitored.

When drawing up a heating temperature schedule, various factors must be taken into account. This list includes not only structural elements building, but the outside temperature, as well as the type of heating system.

Heating temperature chart

Heating temperature graph The supply of heat to a room is associated with a simple temperature graph. The temperature values ​​of the water supplied from the boiler room do not change in the room. They

The coolant temperature in the heating system is normal

Batteries in apartments: accepted temperature standards

Heating batteries today are the main existing elements of the heating system in city apartments. They are effective household devices responsible for heat transfer, since the comfort and coziness in living quarters for citizens directly depends on them and their temperature.

If you refer to the Government Decree Russian Federation No. 354 of May 6, 2011, heating supply to residential apartments begins when the average daily outside air temperature is less than eight degrees, if this mark remains constant for five days. In this case, the start of heat begins on the sixth day after a decrease in the air index was recorded. For all other cases, the law allows delaying the supply of heat resources. In general, in almost all regions of the country the actual heating season directly and officially begins in mid-October and ends in April.

In practice, it also happens that due to the negligence of heat supply companies, the measured temperature of the installed radiators in the apartment does not meet the regulated standards. However, in order to complain and demand correction of the situation, you need to know what standards are in force in Russia and how exactly to correctly measure the existing temperature of operating radiators.

Norms in Russia

Considering the main indicators, the official temperatures of the radiators in the apartment are shown below. They are applicable for absolutely all existing systems in which, in direct accordance with the Decree of the Federal Agency for Construction and Housing and Communal Services No. 170 of September 27, 2003, the coolant (water) is supplied from the bottom up.

In addition, it is necessary to take into account the fact that the temperature of the water that circulates in the radiator directly at the entrance to the functioning heating system must correspond to the current schedules regulated by the utility networks for a particular room. These schedules are regulated by Sanitary Standards and Rules in the sections of heating, air conditioning and ventilation (41-01-2003). Here, in particular, it is indicated that with a two-pipe heating system the maximum temperature indicators are equal to ninety-five degrees, and with a single-pipe heating system - one hundred and five degrees. These measurements must be carried out sequentially in accordance with established rules, otherwise, when contacting higher authorities, the testimony will not be taken into account.

Maintained temperature

The temperature of heating batteries in residential apartments in centralized heating is determined according to the relevant standards, which reflect a sufficient value for the premises, depending on their intended purpose. In this area, the standards are simpler than in the case of work premises, since the activity of residents is, in principle, not so high and more or less stable. Based on this, the following norms are regulated:

Of course, one should take into account individual characteristics each person, everyone has different activities and preferences, which is why there is a difference in the norms from and to, and not one single indicator is fixed.

Requirements for heating systems

Heating in apartment buildings based on the result of many engineering calculations, which are not always very successful. The process is complicated in that it does not involve delivering hot water to a specific property, but rather evenly distributing water throughout all available apartments, taking into account all standards and necessary indicators, including optimal humidity. The effectiveness of such a system depends on how coordinated the actions of its elements are, which also includes radiators and pipes in each room. Therefore, you cannot replace radiator batteries without taking into account the characteristics of heating systems - this leads to negative consequences with a shortage of heat or, conversely, an excess of it.

As for optimizing heating in apartments, the following provisions apply:

In any case, if something bothers the owner, it is worth filing an application with the management company, housing and communal services, or the organization responsible for the supply of heat - depending on what exactly differs from the accepted standards and does not satisfy the applicant.

What to do in case of discrepancies?

If the operating heating systems of an apartment building are functionally adjusted with deviations in the measured temperature only in your premises, you need to check the internal apartment heating systems. First of all, you should make sure that they are not airy. It is necessary to touch the individual batteries available in the living space in the premises from top to bottom and in reverse side– if the temperature is uneven, it means that the cause of the imbalance is airing and you need to bleed the air by turning a separate tap on the radiator batteries. It is important to remember that you cannot open the tap without first placing some container under it for the water to flow into. At first, the water will come out with a hiss, that is, with air; you need to close the tap when it flows without hissing and smoothly. Some time later You should check the places on the battery that were cold - they should now be warm.

If the reason is not in the air, you need to submit an application to the management company. In turn, she must send a responsible technician to the applicant within 24 hours, who must draw up a written conclusion about the inconsistency of the temperature regime and send a team to fix the existing problems.

If the management company has not responded to the complaint, you need to take measurements yourself in the presence of your neighbors.

How to measure temperature?

You should consider how to correctly measure the temperature of radiators. You need to prepare a special thermometer, open the tap and place some container with this thermometer under it. It’s worth noting right away that only an upward deviation of four degrees is permissible. If this is problematic, you need to contact the Housing Office, but if the batteries are airy, submit an application to the DEZ. Everything should be fixed within one week.

There are additional ways to measure the temperature of radiators, namely:

• Measure the temperature of the pipes or battery surfaces with a thermometer and add one or two degrees Celsius to the values ​​thus obtained;
• For accuracy, it is advisable to use infrared thermometers-pyrometers, their error is less than 0.5 degrees;
• Alcohol thermometers are also taken, which are applied to a selected place on the radiator, fixed on it with tape, wrapped with heat-insulating materials and used as permanent measuring instruments;
• If you have any special electrical measuring device, wires with a thermocouple are wound to the batteries.

If the temperature is unsatisfactory, you must file a corresponding complaint.

Minimum and maximum indicators

As well as other indicators that are important to ensure the required living conditions for people (humidity indicators in apartments, supply temperatures warm water, air, etc.), the temperature of the radiators in fact has certain permissible minimums depending on the time of year. However, neither the law nor the established standards prescribe any minimum standards for residential batteries. Based on this, it can be noted that the indicators must be maintained such that the above-mentioned permissible temperatures in the premises are normally maintained. Of course, if the temperature of the water in the radiators is not high enough, it will actually be impossible to ensure the optimal required temperature in the apartment.

If there is no minimum established, then the maximum indicator Sanitary standards and the rules, in particular 01/41/2003, are established. This document defines the standards that are required for an indoor heating system. As mentioned earlier, for two-pipe this is ninety-five degrees, and for single-pipe it is one hundred and fifteen degrees Celsius. However, the recommended temperatures are from eighty-five degrees to ninety, since water boils at one hundred degrees.

Our articles talk about standard methods solutions to legal issues, but each case is unique. If you want to find out how to solve your particular problem, please contact the online consultant form.

What should be the temperature of the coolant in the heating system?

The temperature of the coolant in the heating system is maintained in such a way that in apartments it remains within 20-22 degrees, as the most comfortable for humans. Since its fluctuations depend on the air temperature outside, experts develop schedules with which it is possible to maintain heat indoors in winter.

What determines the temperature in residential premises?

The lower the temperature, the more heat the coolant loses. The indicators of the 5 coldest days of the year are taken into account. The calculation takes into account the 8 coldest winters over the last 50 years. One of the reasons for using such a schedule for many years is the constant readiness of the heating system for extremely low temperatures.

Another reason lies in the field of finance; such a preliminary calculation allows you to save on installing heating systems. If we consider this aspect on a city or district scale, the savings will be impressive.

We list all the factors that affect the temperature inside the apartment:

1. The temperature outside is directly related.
2. Wind speed. Heat loss, for example, through front door, increase with increasing wind speed.
3. The condition of the house, its tightness. This factor is significantly influenced by the use of thermal insulation materials in construction, insulation of the roof, basements, and windows.
4. The number of people inside the room, the intensity of their movement.

All of these factors vary greatly depending on where you live. And the average temperature for last years winter and wind speed depend on where your home is located. For example, in middle lane Russia always has a consistently frosty winter. Therefore, people are often concerned not so much with the temperature of the coolant, but with the quality of construction.

Increasing the cost of building residential real estate, construction companies are taking measures to insulate houses. But still, the temperature of the radiators is no less important. It depends on the temperature of the coolant, which fluctuates in different time, in different climatic conditions.

All requirements for coolant temperature are set out in building codes and regulations. When designing and commissioning engineering systems, these standards must be observed. For calculations, the temperature of the coolant at the outlet of the boiler is taken as a basis.

Indoor temperature standards vary. Eg:

• in the apartment the average is 20-22 degrees;
• in the bathroom it should be 25o;
• in the living room - 18o

In public non-residential premises, temperature standards are also different: at school - 21o, in libraries and gyms - 18o, swimming pool 30o, in industrial premises the temperature is set at about 16oC.

The more people gather indoors, the lower the temperature is initially set. In individual residential buildings, the owners themselves decide what temperature to set.

In order to set the desired temperature, it is important to consider the following factors:

1. Availability of one-pipe or two-pipe system. For the first, the norm is 105°C, for 2 pipes - 95°C.
2. In supply and discharge systems it should not exceed: 70-105°C for a single-pipe system and 70-95°C.
3. Water flow in a certain direction: when distributing from above, the difference will be 20°C, from below - 30°C.
4. Types of heating equipment used. They are divided by the method of heat transfer (radiation devices, convective and convective-radiation devices), by the material used in their manufacture (metal, non-metallic devices, combined), as well as by the magnitude of thermal inertia (small and large).

When combined various properties system, type of heating device, direction of water supply and other things, you can achieve optimal results.

Heating regulators

The device with which the temperature schedule is monitored and the necessary parameters are adjusted is called a heating regulator. The regulator controls the coolant temperature automatically.

The advantages of using these devices:

• maintaining a given temperature schedule;
• by controlling water overheating, additional savings in heat consumption are created;
• setting the most effective parameters;
• all subscribers are provided with the same conditions.

Sometimes the heating regulator is mounted so that it is connected to the same computing node as the hot water regulator.

Such modern methods make the system work more efficiently. Even at the stage when a problem arises, adjustments should be made. Of course, it is cheaper and easier to monitor the heating of a private home, but the automation currently used can prevent many problems.

Coolant temperature in different heating systems

In order to comfortably survive the cold season, you need to worry about creating a high-quality heating system in advance. If you live in a private house, you have an autonomous network, and if you live in an apartment complex, you have a centralized one. Whatever it is, it is still necessary that the temperature of the batteries during the heating season is within the limits established by SNiP. In this article we will analyze the coolant temperature for different systems heating.

The heating season begins when the average outside temperature per day drops below +8°C and stops, respectively, when it rises above this mark, but it also lasts for up to 5 days.

Standards. What temperature should be in the rooms (minimum):

• In the living room +18°C;
• IN corner room+20°C;
• In the kitchen +18°C;
• In the bathroom +25°C;
• In corridors and stairwells +16°C;
• In the elevator +5°C;
• In the basement +4°C;
• In the attic +4°C.

It should be taken into account that the data temperature standards refer to the heating season and do not apply to the rest of the time. Also, it will be useful information that hot water should be from +50°C to +70°C, according to SNiP-u 2.08.01.89 “Residential buildings”.

There are several types of heating systems:

With natural circulation

The coolant circulates without interruption. This is due to the fact that the temperature and density of the coolant changes continuously. Because of this, heat is distributed evenly across all elements of the heating system with natural circulation.

The circular water pressure directly depends on the temperature difference between hot and cooled water. Typically, in the first heating system the coolant temperature is 95°C, and in the second 70°C.

With forced circulation

This system is divided into two types:

The difference between them is quite big. The layout of the pipes, their number, and the sets of shut-off, control and control valves differ.

According to SNiP 41-01-2003 (“Heating, ventilation and air conditioning”), the maximum coolant temperature in these heating systems is:

• two-pipe heating system - up to 95°C;
• single-pipe - up to 115°C;

The optimal temperature is from 85°C to 90°C (due to the fact that at 100°C, water already boils. When this value is reached, special measures must be used to stop boiling).

The amount of heat emitted by the radiator depends on the installation location and the method of connecting the pipes. Thermal output can be reduced by 32% due to poor pipe placement.

The best option is a diagonal connection when hot the water is flowing on top, and the return is on the bottom of the opposite side. This is how radiators are tested during testing.

The worst thing is when hot water comes from below, and cold water comes from above on the same side.

Calculation optimal temperature heating device

The most important thing is that the most comfortable temperature for human existence is +37°C.

• where S is the area of ​​the room;
• h – room height;
• 41 – minimum power per 1 cubic m S;
• 42 – nominal thermal conductivity of one section according to the passport.

Please note that a radiator placed under a window in a deep niche will produce almost 10% less heat. A decorative box will take 15-20%.

When you use a radiator to maintain the desired temperature in a room, you have two options: you can use small radiators and increase the water temperature in them (high temperature heating) or install a large radiator, but the surface temperature will not be as high (low temperature heating) .

With high temperature heating, radiators are very hot and can cause burns if you touch them. In addition, when high temperature radiator, the decomposition of dust settled on it may begin, which will then be inhaled by people.

When using low temperature heating, the appliances are slightly warm, but the room is still warm. In addition, this method is more economical and safe.

Cast iron radiators

The average heat output of a separate section of a radiator made of this material ranges from 130 to 170 W, due to the thick walls and large mass of the device. Therefore, it takes a lot of time to warm up the room. Although this also has the opposite advantage - high inertia ensures long-term retention of heat in the radiator after the boiler is turned off.

The coolant temperature in it is 85-90 °C

Aluminum radiators

This material is lightweight, easily heats up and has good heat dissipation from 170 to 210 watts/section. However, it is susceptible to the negative effects of other metals and may not be installed in every system.

The operating temperature of the coolant in the heating system with this radiator is 70°C

Steel radiators

The material has even lower thermal conductivity. But due to the increase in surface area with partitions and ribs, it still heats well. Heat output from 270 W - 6.7 kW. However, this is the power of the entire radiator, and not of its individual segment. The final temperature depends on the dimensions of the heater and the number of fins and plates in its design.

The operating temperature of the coolant in the heating system with this radiator is also 70°C

So which one is better?

It will probably be more profitable to install equipment with a combination of the properties of aluminum and steel battery - bimetallic radiator. It will cost you more, but it will also last longer.

The advantage of such devices is obvious: if aluminum can withstand the temperature of the coolant in the heating system only up to 110°C, then bimetal can withstand up to 130°C.

Heat transfer, on the contrary, is worse than that of aluminum, but better than that of other radiators: from 150 to 190 W.

Warm floor

Another way to create a comfortable temperature environment in the room. What are its advantages and disadvantages over conventional radiators?

From a school physics course we know about the phenomenon of convection. Cold air tends downward, and when it heats up, it rises up. That’s why, by the way, my feet get cold. A warm floor changes everything - the heated air below is forced to rise upward.

This coating has a high heat output (depending on the area of ​​the heating element).

The floor temperature is also specified in SNiP-e (“Building Norms and Rules”).

In the house for permanent residence it should not be more than +26°C.

In rooms for temporary stay of people up to +31°C.

In institutions where children are taught, the temperature should not exceed +24°C.

The operating temperature of the coolant in the underfloor heating system is 45-50 °C. Surface temperature averages 26-28°C

How to regulate heating radiators and what should be the temperature in the apartment according to SNiP and SanPiN

To feel comfortable in an apartment or in own home In winter, a reliable heating system that meets standards is required. In a multi-story building, this is usually centralized network, in private households - heating system. For the end consumer, the main element of any heating system is the battery. The coziness and comfort in the house depends on the heat coming from it. The temperature of the heating radiators in the apartment, its norm is regulated by legislative documents.

Radiator heating standards

If the house or apartment has independent heating, adjusting the temperature of the radiators and taking care of maintaining the thermal regime falls on the homeowner. In a multi-storey building with centralized heating, the authorized organization is responsible for compliance with the standards. Heating standards are developed on the basis of sanitary standards that apply to residential and non-residential premises. The calculations are based on the needs of an ordinary body. Optimal values ​​are established by law and reflected in SNiP.

The apartment will be warm and cozy only when the heat supply standards required by law are met.

When is heat connected and what standards apply?

The beginning of the heating season in Russia occurs at a time when the thermometer readings drop below +8°C. The heating is turned off when the mercury rises to +8°C and above, and remains at this level for 5 days.

To determine whether the battery temperature meets the standards, it is necessary to take measurements

Minimum temperature standards

In accordance with heat supply standards, minimum temperature should be like this:

• living rooms: +18°C;
• corner rooms: +20°C;
• bathrooms: +25°C;
• kitchens: +18°C;
• staircases and lobbies: +16°C;
• basements: +4°C;
• attics: +4°C;
• elevators: +5°C.

This value is measured indoors at a distance of one meter from external wall and 1.5 m from the floor. In case of hourly deviations from the established standards, the heating fee is reduced by 0.15%. The water must be heated to +50°C – +70°C. Its temperature is measured with a thermometer, lowering it to a special mark in a container with tap water.

Standards according to SanPiN 2.1.2.1002-00

Standards according to SNiP 2.08.01-89

It’s cold in the apartment: what to do and where to go

If the radiators do not heat well, the water temperature in the tap will be lower than normal. In this case, residents have the right to write a statement requesting an inspection. Representatives of the utility service inspect the water supply and heating systems and draw up a report. The second copy is given to residents.

If the radiators are not warm enough, you need to contact the organization responsible for heating the house

If the complaint is confirmed, the authorized organization is obliged to correct everything within a week. Rent is recalculated if the room temperature deviates from permissible norm, and also when the water in the radiators during the daytime is below the standard by 3°C, at night - by 5°C.

Quality requirements utilities, prescribed in Resolution No. 354 of May 6, 2011 on the rules for the provision of utility services to owners and users of premises in apartment buildings and residential buildings

Air ratio parameters

The air exchange rate is a parameter that must be observed in heated rooms. In a living room with an area of ​​18 m² or 20 m², the multiplicity should be 3 m³/h per square meter. m. The same parameters must be observed in regions with temperatures down to -31°C and below.

In apartments equipped with gas and electric stoves with two burners, and dormitory kitchens with an area of ​​up to 18 m², aeration is 60 m³/h. In rooms with a three-burner appliance, this value is 75 m³/h, s gas stove with four burners - 90 m³/h.

In a bathroom with an area of ​​25 m², this parameter is 25 m³/h, in a toilet with an area of ​​18 m² - 25 m³/h. If the bathroom is combined and its area is 25 m², the air exchange rate will be 50 m³/h.

Methods for measuring radiator heating

The taps are supplied with hot water all year round, heated to +50°С – +70°С. During the heating season, heating devices are filled with this water. To measure its temperature, open the tap and place a container under the stream of water, into which the thermometer is lowered. Deviations are allowed by four degrees upward. If a problem exists, file a complaint with the Housing Office. If the radiators are airy, the application must be written to the DEZ. A specialist should show up within a week and fix everything.

The presence of a measuring device will allow you to constantly monitor the temperature regime

Methods for measuring the heating of heating batteries:

1. The heating of the pipe and radiator surfaces is measured with a thermometer. 1-2°C is added to the result obtained.
2. For the most accurate measurements, an infrared thermometer-pyrometer is used, which determines readings with an accuracy of 0.5°C.
3. A permanent measuring device can be an alcohol thermometer, which is applied to the radiator, glued with tape, and wrapped with foam rubber or other heat-insulating material on top.
4. The heating of the coolant is also measured by electrical measuring instruments with the “measure temperature” function. To measure, a wire with a thermocouple is screwed to the radiator.

By regularly recording the device data and recording the readings in a photo, you will be able to file a claim against the heat supplier

Important! If the radiators do not heat up enough, after submitting an application to an authorized organization, a commission should come to you and measure the temperature of the liquid circulating in the heating system. The actions of the commission must comply with paragraph 4 of “Control Methods” in accordance with GOST 30494−96. The device used for measurements must be registered, certified and undergo state verification. Its temperature range should be from +5 to +40°С, the permissible error is 0.1°С.

Adjusting heating radiators

Adjusting the temperature of heating radiators is necessary in order to save on heating the room. In high-rise apartments, the heating bill will decrease only after installing a meter. If a private house has a boiler that automatically maintains a stable temperature, regulators may not be needed. If the equipment is not automated, the savings will be significant.

Why is adjustment needed?

Adjusting the batteries will help achieve not only maximum comfort, but also:

• Remove airing, ensure the movement of the coolant through the pipeline and transfer heat to the room.
• Reduce energy costs by 25%.
• Do not constantly open windows due to overheating of the room.

Heating adjustments must be made before the start of the heating season. Before this, you need to insulate all windows. In addition, the location of the apartment is taken into account:

• corner;
• in the middle part of the house;
• on the lower or upper floors.

• insulation of walls, corners, floors;
• hydro- and thermal insulation of joints between panels.

Without these measures, adjustment will not be beneficial, since more than half of the heat will warm the street.

Insulating a corner apartment will help reduce heat loss as much as possible

The principle of adjusting radiators

How to properly regulate heating batteries? To rationally use heat and ensure uniform heating, valves are installed on the batteries. With their help, you can reduce the water flow or disconnect the radiator from the system.

• In centralized heating systems of high-rise buildings with a pipeline through which coolant is supplied from top to bottom, it is impossible to regulate radiators. The upper floors of such houses are hot, the lower floors are cold.
• In a single-pipe network, coolant is supplied to each battery and returned to the central riser. The heat is distributed evenly here. Control valves are installed on the radiator supply pipes.
• IN two-pipe systems with two risers, the coolant is supplied to the battery and back. Each of them is equipped with a separate valve with a manual or automatic thermostat.

Types of control valves

Modern technologies allow the use of special control valves, which are heat exchangers shut-off valves, connected to the battery. There are several types of taps that allow you to regulate heat.

Operating principle of control valves

According to the principle of action they are:

• Ball, providing 100% protection against accidents. They can rotate 90 degrees, allow water to pass through or shut off the coolant.
• Standard budget valves without temperature scale. They partially change the temperature, blocking the access of the coolant to the radiator.
• With a thermal head that regulates and controls system parameters. There are mechanical and automatic.

Operating a ball valve involves turning the regulator to one side.

Note! The ball valve should not be left half-open, as this may damage the O-ring, resulting in a leak.

Conventional direct-acting thermostat

A direct-acting thermostat is a simple device installed near a radiator that allows you to control the temperature in it. Structurally, it is a sealed cylinder with a bellows inserted into it, filled with a special liquid or gas that can respond to temperature changes. Its increase causes expansion of the filler, resulting in increased pressure on the rod in the regulator valve. It moves and blocks the coolant flow. Cooling the radiator causes the opposite process.

A direct-acting thermostat is installed in the heating system pipeline

Thermostat with electronic sensor

The principle of operation of the device is similar to the previous version, the only difference is in the settings. In a conventional thermostat, they are performed manually; in an electronic sensor, the temperature is set in advance and maintained within specified limits (from 6 to 26 degrees) automatically.

A programmable thermostat for heating radiators with an internal sensor is installed when it is possible to place its axis horizontally

Instructions for adjusting heat

How to regulate batteries, what actions need to be taken to ensure comfortable conditions in the house:

1. Air is released from each battery until water flows from the tap.
2. Pressure is regulated. To do this, the valve in the first battery from the boiler opens two turns, in the second - three turns, etc., adding one turn for each subsequent radiator. This scheme ensures optimal coolant flow and heating.
3. IN coercive systems pumping of coolant and control of heat consumption are carried out using control valves.
4. Built-in thermostats are used to regulate heat in a flow-through system.
5. In two-pipe systems, in addition to the main parameter, the amount of coolant is controlled in manual and automatic mode.

What is a thermal head for radiators needed for and how does it work:

Comparison of temperature control methods:

Comfortable accommodation in high-rise apartments, in country houses and cottages is ensured by maintaining a certain thermal regime in the premises. Modern systems heating systems allow you to install regulators that maintain the required temperature. If installing regulators is not possible, responsibility for the heat in your apartment rests with the heat supply organization, which you can contact if the air in the room does not warm up to the values ​​required by the standards.

The coolant temperature in the heating system is normal

Batteries in apartments: accepted temperature standards Heating batteries today are the main existing elements of the heating system in city apartments. They represent...

The supply of heat to a room is associated with a simple temperature schedule. The temperature values ​​of the water supplied from the boiler room do not change in the room. They have standard values ​​and range from +70ºС to +95ºС. This temperature schedule for the heating system is the most popular.

Adjusting the air temperature in the house

Not everywhere in the country there is centralized heating, so many residents install independent systems. Their temperature graph differs from the first option. In this case, temperature indicators are significantly reduced. They depend on the efficiency of modern heating boilers.

If the temperature reaches +35ºС, the boiler will operate at maximum power. This depends on the heating element, where thermal energy can be captured by the exhaust gases. If the temperature values ​​are greater than + 70 ºС, then the boiler performance drops. In this case, its technical characteristics indicate an efficiency of 100%.

Temperature schedule and its calculation

What the graph will look like depends on the outside temperature. The more negative the outside temperature, the greater the heat loss. Many people do not know where to get this indicator. This temperature is prescribed in regulatory documents. The temperature of the coldest five-day period is taken as the calculated value, and the lowest value over the last 50 years is taken.

Graph of the dependence of external and internal temperatures

The graph shows the relationship between external and internal temperatures. Let's say the outside temperature is -17ºС. Drawing a line upward until it intersects with t2, we obtain a point characterizing the temperature of the water in the heating system.

Thanks to the temperature schedule, you can prepare the heating system even for the most severe conditions. It also reduces material costs for installing a heating system. If we consider this factor from the point of view of mass construction, the savings are significant.

inside premises depends from temperature coolant, A Also others factors:

• Outside air temperature. The smaller it is, the more negatively it affects heating;
• Wind. When strong wind occurs, heat loss increases;
• The temperature inside the room depends on the thermal insulation of the structural elements of the building.

Over the past 5 years, construction principles have changed. Builders increase the value of a home by insulating elements. As a rule, this applies to basements, roofs, and foundations. These expensive measures subsequently allow residents to save on the heating system.

Heating temperature chart

The graph shows the dependence of the temperature of external and internal air. The lower the outside air temperature, the higher the coolant temperature in the system will be.

A temperature schedule is developed for each city during the heating season. In small settlements, a boiler room temperature schedule is drawn up, which provides the required amount of coolant to the consumer.

Change temperature schedule Can several ways:

• quantitative - characterized by a change in the flow rate of coolant supplied to the heating system;
• qualitative - consists of regulating the temperature of the coolant before supplying it to the premises;
• temporary - a discrete method of supplying water to the system.

The temperature schedule is a schedule of heating pipes that distributes the heating load and is regulated using centralized systems. There is also an increased schedule; it is created for a closed heating system, that is, to ensure the supply of hot coolant to connected objects. When using an open system, it is necessary to adjust the temperature schedule, since the coolant is consumed not only for heating, but also for domestic water consumption.

The temperature graph is calculated using a simple method. Hto build it, necessary initial temperature air data:

• external;
• in room;
• in the supply and return pipelines;
• at the exit of the building.

In addition, you should know the rated thermal load. All other coefficients are standardized by reference documentation. The system is calculated for any temperature schedule, depending on the purpose of the room. For example, for large industrial and civil facilities a schedule of 150/70, 130/70, 115/70 is drawn up. For residential buildings this figure is 105/70 and 95/70. The first indicator shows the supply temperature, and the second - the return temperature. The calculation results are entered into a special table, which shows the temperature at certain points of the heating system, depending on the outside air temperature.

The main factor in calculating the temperature schedule is the outside air temperature. The calculation table must be drawn up so that the maximum values ​​of the coolant temperature in the heating system (graph 95/70) ensure heating of the room. Room temperatures are prescribed by regulatory documents.

heating devices

Heating device temperature

The main indicator is the temperature of heating devices. The ideal temperature schedule for heating is 90/70ºС. It is impossible to achieve such an indicator, since the temperature inside the room should not be the same. It is determined depending on the purpose of the room.

In accordance with the standards, the temperature in the corner living room is +20ºС, in the rest – +18ºС; in the bathroom – +25ºС. If the outside air temperature is -30ºС, then the indicators increase by 2ºС.

Except Togo, exists norms For others types premises:

• in rooms where children are located – +18ºС to +23ºС;
• children's educational institutions – +21ºС;
• in cultural institutions with mass attendance – +16ºС to +21ºС.

This range of temperature values ​​is compiled for all types of premises. It depends on the movements performed inside the room: the more there are, the lower the air temperature. For example, in sports facilities people move a lot, so the temperature is only +18ºС.

Room temperature

Exist certain factors, from which depends temperature heating devices:

• Outside air temperature;
• Type of heating system and temperature difference: for a single-pipe system – +105ºС, and for a single-pipe system – +95ºС. Accordingly, the differences in for the first region are 105/70ºС, and for the second – 95/70ºС;
• Direction of coolant supply to heating devices. With the top feed, the difference should be 2 ºС, with the bottom – 3 ºС;
• Type of heating devices: heat transfer is different, so the temperature curve will be different.

First of all, the coolant temperature depends on the outside air. For example, the temperature outside is 0ºC. In this case, the temperature regime in the radiators should be 40-45ºC at the supply, and 38ºC at the return. When the air temperature is below zero, for example -20ºС, these indicators change. In this case, the supply temperature becomes 77/55ºС. If the temperature reaches -40ºС, then the indicators become standard, that is, +95/105ºС at the supply, and +70ºС at the return.

Additional options

In order for a certain temperature of the coolant to reach the consumer, it is necessary to monitor the condition of the outside air. For example, if it is -40ºС, the boiler room should supply hot water with an indicator of +130ºС. Along the way, the coolant loses heat, but the temperature still remains high when it enters the apartments. The optimal value is +95ºС. To do this, an elevator unit is installed in the basements, which serves to mix hot water from the boiler room and coolant from the return pipeline.

Several institutions are responsible for the heating main. The boiler room monitors the supply of hot coolant to the heating system, and the condition of the pipelines is monitored by city heating networks. The housing office is responsible for the elevator element. Therefore, to solve the problem of supplying coolant to a new house, you need to contact different offices.

Installation of heating devices is carried out in accordance with regulatory documents. If the owner himself replaces the battery, then he is responsible for the operation of the heating system and changes in temperature conditions.

Adjustment methods

Dismantling the elevator unit

If the boiler room is responsible for the parameters of the coolant leaving the warm point, then the housing office workers must be responsible for the temperature inside the room. Many residents complain about the cold in their apartments. This occurs due to a deviation in the temperature graph. In rare cases, it happens that the temperature rises by a certain value.

Heating parameters can be adjusted in three ways:

• Reaming the nozzle.

If the supply and return coolant temperatures are significantly underestimated, then it is necessary to increase the diameter of the elevator nozzle. This way, more liquid will pass through it.

How to do this? To begin with, shut-off valves are closed (house valves and taps at the elevator unit). Next, the elevator and nozzle are removed. Then it is drilled out by 0.5-2 mm, depending on how much it is necessary to increase the temperature of the coolant. After these procedures, the elevator is mounted in its original place and put into operation.

To ensure sufficient tightness of the flange connection, it is necessary to replace the paronite gaskets with rubber ones.

• Silence the suction.

In severe cold weather, when the problem of freezing of the heating system in the apartment arises, the nozzle can be completely removed. In this case, the suction may become a jumper. To do this, you need to plug it with a steel pancake 1 mm thick. This process is carried out only in critical situations, since the temperature in pipelines and heating devices will reach 130ºC.

• Adjustment of difference.

In the middle of the heating season, a significant increase in temperature may occur. Therefore, it is necessary to regulate it using a special valve on the elevator. To do this, the supply of hot coolant is switched to the supply pipeline. A pressure gauge is mounted on the return line. Adjustment occurs by closing the valve on the supply pipeline. Next, the valve opens slightly, and the pressure should be monitored using a pressure gauge. If you simply open it, the cheeks will sag. That is, an increase in pressure drop occurs in the return pipeline. Every day the indicator increases by 0.2 atmospheres, and the temperature in the heating system must be constantly monitored.

Heat supply. Video

How is the heat supply of private and apartment buildings, you can find out from the video below.

When drawing up a heating temperature schedule, various factors must be taken into account. This list includes not only the structural elements of the building, but the outside temperature, as well as the type of heating system.

In contact with

Each heating system has certain characteristics. These include power, heat transfer and operating temperature. They determine the efficiency of work, directly affecting the comfort of living in the house. How to choose the right temperature schedule and heating mode, and its calculation?

Drawing up a temperature chart

The temperature schedule of the heating system is calculated using several parameters. Not only the degree of heating of the premises, but also the coolant consumption depends on the selected mode. This also affects the current costs of heating maintenance.

The compiled heating temperature schedule depends on several parameters. The main one is the level of water heating in the mains. It, in turn, consists of the following characteristics:

• Temperature in the supply and return pipes. Measurements are taken in the corresponding boiler nozzles;
• Characteristics of the degree of air heating indoors and outdoors.

Correct calculation of the heating temperature schedule begins with calculating the difference between the temperature of hot water in the direct and supply pipes. This value has the following designation:

∆T=Tin-Tob

Where Tin– water temperature in the supply line, Tob– degree of water heating in the return pipe.

To increase the heat transfer of the heating system, it is necessary to increase the first value. To reduce coolant flow, ∆t should be minimal. This is precisely the main difficulty, since the temperature schedule of the heating boiler directly depends on external factors - heat losses in the building, air outside.

To optimize heating power, it is necessary to insulate the external walls of the house. This will reduce heat losses and energy consumption.

Temperature calculation

To determine the optimal temperature regime, it is necessary to take into account the characteristics of heating components - radiators and batteries. In particular, specific power (W/cm²). This will directly affect the thermal transfer of heated water to the air in the room.

It is also necessary to make a number of preliminary calculations. This takes into account the characteristics of the house and heating devices:

• Heat transfer resistance coefficient of external walls and window structures. It must be at least 3.35 m²*C/W. Depends on the climatic characteristics of the region;
• Surface power of radiators.

The temperature graph of the heating system is directly dependent on these parameters. To calculate the heat loss of a house, you need to know the thickness of the external walls and the material of the building. The surface power of batteries is calculated using the following formula:

Ore=P/Fact

Where R– maximum power, W, fact– radiator area, cm².

According to the data obtained, a temperature regime for heating and a heat transfer graph are drawn up depending on the outside temperature.

To change heating parameters in a timely manner, install a heating temperature regulator. This device connects to outdoor and indoor thermometers. Depending on the current indicators, the operation of the boiler or the volume of coolant flow into the radiators is adjusted.

The weekly programmer is the optimal heating temperature regulator. With its help, you can automate the operation of the entire system as much as possible.

Central heating

For district heating, the temperature regime of the heating system depends on the characteristics of the system. Currently, there are several types of coolant parameters supplied to consumers:

• 150°C/70°C. To normalize the water temperature, the elevator unit mixes it with the cooled stream. In this case, you can create an individual temperature schedule for the heating boiler room for a specific house;
• 90°С/70°С. Typical for small private heating systems designed to supply heat to several apartment buildings. In this case, you do not need to install the mixing unit.

The responsibility of utility services is to calculate the temperature heating schedule and control its parameters. In this case, the degree of air heating in residential premises should be at +22°C. For non-residential residents this figure is slightly lower – +16°C.

For centralized system drawing up the correct temperature schedule for the heating boiler room is required to ensure optimal comfortable temperature in apartments. The main problem is the lack feedback– it is impossible to regulate the coolant parameters depending on the degree of air heating in each apartment. That is why a temperature graph of the heating system is drawn up.

A copy of the heating schedule can be requested from the Management Company. With its help you can control the quality of the services provided.

Heating system

Do similar calculations for autonomous systems Heating a private home is often not necessary. If the circuit includes indoor and outdoor temperature sensors, information about them will be sent to the boiler control unit.

Therefore, to reduce energy consumption, low-temperature heating modes are most often chosen. It is characterized by relatively low heating of water (up to +70°C) and a high degree of circulation. This is necessary for uniform heat distribution across all heating devices.

To implement such a temperature regime for the heating system, the following conditions will need to be met:

• Minimum heat losses in the house. However, one should not forget about normal air exchange - ventilation is mandatory;
• High thermal output of radiators;
• Installation of automatic temperature controllers in heating.

If there is a need to perform a correct calculation of the system’s operation, it is recommended to use special software systems. There are too many factors to take into account to calculate on your own. But with their help you can create approximate temperature graphs of heating modes.

However, it should be borne in mind that an accurate calculation of the heat supply temperature schedule is done for each system individually. The tables show the recommended values ​​for the degree of heating of the coolant in the supply and return pipes depending on the outside temperature. When performing calculations, the characteristics of the building and the climatic features of the region were not taken into account. But even despite this, they can be used as a basis for creating a temperature chart for the heating system.

The maximum load of the system should not affect the quality of boiler operation. Therefore, it is recommended to purchase it with a power reserve of 15-20%.

Even the most accurate temperature schedule of a heating boiler room will exhibit deviations in calculated and actual data during operation. This is due to the operating features of the system. What factors can influence the current temperature regime of heat supply?

• Contamination of pipelines and radiators. To avoid this, the heating system should be cleaned periodically;
• Incorrect operation of control and shut-off valves. The functionality of all components must be checked;
• Violation of the boiler's operating mode - sudden changes in temperature and, as a consequence, pressure.

Maintaining the optimal temperature regime of the system is only possible with making the right choice its components. To do this, their operational and technical properties should be taken into account.

The battery heating can be adjusted using a thermostat, the operating principle of which can be found in the video: