Coolant supply temperature graph. Temperature diagram of the heating network - tips for drawing up. Temperature chart and its calculation
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To maintain a comfortable temperature in the house during the heating season, it is necessary to control the temperature of the coolant in the pipes of the heating networks. Workers of the residential central heating system are developing special temperature chart, which depends on weather indicators and climatic characteristics of the region. The temperature schedule may differ in different localities, and it may also change when heating networks are modernized.
A schedule is drawn up in the heating network according to a simple principle - the lower the temperature outside, the higher it should be for the coolant.
This ratio is important basis for work enterprises that provide the city with heat.
For the calculation, an indicator was used, which is based on average daily temperature five coldest days of the year.
ATTENTION! Maintaining the temperature regime is important not only for maintaining heat in an apartment building. It also allows you to make energy consumption in the heating system economical and rational.
A schedule that indicates the temperature of the coolant depending on the outside temperature allows you to distribute not only heat, but also hot water among the consumers of an apartment building in the most optimal way.
How is heat regulated in a heating system?
Heat regulation in an apartment building during the heating season can be carried out using two methods:
- By changing the flow of water at a certain constant temperature. This is a quantitative method.
- Changing the coolant temperature at a constant flow volume. This is a qualitative method.
Economical and practical second option, in which the temperature in the room is maintained regardless of the weather. The supply of sufficient heat to an apartment building will be stable, even if there is a sharp change in temperature outside.
ATTENTION!. The norm is considered to be a temperature of 20-22 degrees in the apartment. If temperature schedules are observed, this norm is maintained throughout the heating period, regardless of weather conditions and wind direction.
When the temperature outside decreases, data is transmitted to the boiler room and the coolant temperature automatically increases.
The specific table of the relationship between outdoor temperature and coolant depends on factors such as climate, boiler room equipment, technical and economic indicators.
Reasons to use a temperature graph
The basis for the operation of each boiler house serving residential, administrative and other buildings during the heating season is the temperature schedule, which indicates the standards for coolant indicators depending on what the actual outside temperature is.
- Drawing up a schedule makes it possible to prepare the heating for a drop in outside temperature.
- It also saves energy resources.
ATTENTION! In order to control the temperature of the coolant and have the right to recalculate due to non-compliance with the thermal regime, a heat sensor must be installed in the centralized heating system. Metering devices must undergo annual inspection.
Modern construction companies can increase the cost of housing through the use of expensive energy-saving technologies in the construction of multi-apartment buildings.
Despite changes in construction technologies, the use of new materials for insulating walls and other surfaces of a building, compliance with the normal coolant temperature in the heating system is the best way to maintain comfortable living conditions.
Features of calculating internal temperature in different rooms
The rules provide for maintaining the temperature for living quarters at 18˚С, but there are some nuances in this matter.
- For angular rooms of a residential building coolant should provide a temperature of 20˚C.
- Optimal temperature indicator for the bathroom - 25˚С.
- It is important to know how many degrees there should be according to standards in rooms intended for children. Indicator set from 18˚С to 23˚С. If this is a children's pool, you need to maintain the temperature at 30˚C.
- Minimum temperature allowed in schools - 21˚С.
- In establishments where cultural events take place, the standards support maximum temperature 21˚С, but the indicator should not fall below 16˚С.
To increase the temperature in the premises during sudden cold snaps or strong north winds, boiler room workers increase the degree of energy supply for heating networks.
The heat transfer of batteries is affected by the outside temperature, the type of heating system, the direction of coolant flow, the state of utility networks, and the type of heating device, the role of which can be played by either a radiator or a convector.
ATTENTION! The temperature delta between the radiator supply and return should not be significant. Otherwise, there will be a large difference in the coolant in different rooms and even apartments of a multi-story building.
The main factor, however, is the weather., which is why measuring the outside air to maintain a temperature schedule is a top priority.
If the temperature outside is down to 20˚C, the coolant in the radiator should be 67-77˚C, while the return rate is 70˚C.
If the street temperature is zero, the norm for the coolant is 40-45˚С, and for the return – 35-38˚С. It is worth noting that the temperature difference between supply and return is not large.
Why does the consumer need to know the coolant supply standards?
Payment for utilities in the heating column should depend on the temperature in the apartment provided by the supplier.
The temperature chart table, according to which the boiler should operate optimally, shows at what ambient temperature and by how much the boiler room should increase the energy level for heat sources in the house.
IMPORTANT! If the parameters of the temperature schedule are not met, the consumer may request a recalculation for utilities.
To measure the coolant value, you need to drain some water from the radiator and check its heat level. Also successfully used thermal sensors, heat meters that can be installed at home.
The sensor is mandatory equipment for both city boiler houses and ITPs (individual heating points).
Without such devices it is impossible to make the heating system work economically and productively. The coolant is also measured in DHW systems.
Useful video
The basis for an economical approach to energy consumption in a heating system of any type is the temperature schedule. Its parameters indicate the optimal value for heating water, thereby optimizing costs. In order to apply this data in practice, it is necessary to learn in more detail the principles of its construction.
Terminology
Temperature graph – the optimal value of heating the coolant to create a comfortable temperature in the room. It consists of several parameters, each of which directly affects the quality of operation of the entire heating system.
- Temperature in the inlet and outlet pipes of the heating boiler.
- The difference between these coolant heating indicators.
- Temperature indoors and outdoors.
The latter characteristics are decisive for the regulation of the first two. Theoretically, the need to increase the heating of water in the pipes occurs when the temperature outside decreases. But how much do you need to increase so that the heating of the air in the room is optimal? To do this, draw up a graph of the dependence of the parameters of the heating system.
When calculating it, the parameters of the heating system and the residential building are taken into account. For centralized heating, the following system temperature parameters are accepted:
- 150°C/70°C. Before reaching the users, the coolant is diluted with water from the return pipe to normalize the incoming temperature.
- 90°C/70°C. In this case, there is no need to install equipment for mixing the flows.
According to the current system parameters, utilities must monitor compliance with the heating value of the coolant in the return pipe. If this parameter is less than normal, it means that the room is not heated properly. Exceeding indicates the opposite - the temperature in the apartments is too high.
Temperature chart for a private house
The practice of drawing up such a schedule for autonomous heating is not very developed. This is explained by its fundamental difference from the centralized one. The water temperature in the pipes can be controlled manually or automatically. If the design and practical implementation took into account the installation of sensors for automatically regulating the operation of the boiler and thermostats in each room, then there will be no urgent need to calculate the temperature schedule.
But it will be indispensable for calculating future expenses depending on weather conditions. In order to draw it up in accordance with the current rules, the following conditions must be taken into account:
Only after these conditions have been met can we proceed to the calculation part. Difficulties may arise at this stage. Correct calculation of an individual temperature schedule is a complex mathematical scheme that takes into account all possible indicators.
However, to make the task easier, there are ready-made tables with indicators. Below are examples of the most common operating modes of heating equipment. The following input data were taken as initial conditions:
- Minimum air temperature outside – 30°C
- The optimal room temperature is +22°C.
Based on these data, schedules were drawn up for the following types of operation of heating systems.
Temperature graph of coolant supply to the heating system
Each management company strives to achieve economical costs for heating an 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.
Correct use of this data allows optimal distribution of 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 a 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.
note
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.
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.
The heat supply temperature schedule refers to the schedules of heating-carrying pipelines, which are regulated by a centralized system and share the heating load. The system can be either closed or open.
In the case when the system is closed, it goes only to heating objects connected to the heating network. When the system is open, it is also used to supply hot water to consumers.
If an open system is used, adjustments must be made due to constant heat consumption.
How to make a temperature chart
In accordance with SNIP, indoor heating should be maintained at a level of 18 to 25 °C.
SNIP for preschool and school educational institutions is usually stricter, since the temperature must be constant and not fall below 22°C.
In educational institutions, they strictly monitor compliance with sanitary standards - pipes cannot be covered with mold. To calculate a temperature graph, you need to know the values of several indicators:
- Outside air temperature;
- In living rooms;
- In the supply part of the pipeline;
- In the back part of the pipeline;
- In the pipeline at the exit from the building.
In addition to this data, you need to know what the nominal heat load is. For residential buildings, a similar heating schedule is 105/70 and 95/70. The first indicator reflects the temperature that should be at the water supply to the heating system, the second - at the outlet or return pipe.
The results obtained from the measurements must be entered into the table. The main indicator for compiling the table is the outside temperature. It must be compiled in such a way that the maximum data of heating devices - 95/70 - ensures heating of the premises.
The temperature regime that must be maintained in apartments is enshrined in the article of the Housing Code of the Russian Federation and the Resolution of the State Standard.
A similar calculation of temperatures maintained in a residential area is made by the management company for each high-rise or two-story building separately. All indicators, thermal insulation of external heating parts and other significant points are taken into account.
A heating schedule built according to all the rules will help not only determine the operating parameters of the system at each moment in time, but also evaluate the efficiency of the coolant.
The construction of such a graph also allows you to determine the amount of load on the heating system.
Table of coolant temperature versus outside air temperature
It is important to take into account their surface thickness and the coefficient of resistance available at window openings and external walls.
After all the values are 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
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. The temperature in the remaining rooms should also increase, provided that it may be different in rooms for different purposes. If there is a child in the room, then it can fluctuate from 18 C to 23 C.
In storerooms and corridors, heating can vary from 12 C to 18 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 looks like this:
Boiling temperature
Pressure
The supply of hot water in the winter season 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 closed-type and open-type heat supply systems.
Heating schedule for qualitative regulation of heat supply based on average daily outside air temperature
Looking through the statistics of visits to our blog, I noticed that search phrases such as, for example, “what should be the coolant temperature at minus 5 outside?” appear very often.
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 regulating the temperature of the coolant). Heating networks in Ufa (Bashkiria) operate according to this schedule.
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 оС.
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 °C 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 oC with a 105/70 schedule or 65.3 oC with a 95/70 schedule. The water temperature after the heating system should be 51,7 oS.
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 °C, but at a thermal power plant or boiler house it is set to 87 degrees.
Outdoor air temperature Тнв, оС Temperature of network water in the supply pipeline Т1, оС Temperature of water in the supply pipeline of the heating system Т3, оС Temperature of water after the heating system Т2, оС
15013011510595
8
53,2
50,2
46,4
43,4
41,2
35,8
55,7
52,3
48,2
45,0
42,7
36,8
58,1
54,4
50,0
46,6
44,1
37,7
60,5
56,5
51,8
48,2
45,5
38,7
62,9
58,5
53,5
49,8
46,9
39,6
65,3
60,5
55,3
51,4
48,3
40,6
67,7
62,6
57,0
52,9
49,7
41,5
70,0
64,5
58,8
54,5
51,0
42,4
72,4
66,5
60,5
56,0
52,4
43,3
74,7
68,5
62,2
57,5
53,7
44,2
77,0
70,4
63,8
59,0
55,0
45,0
79,3
72,4
65,5
60,5
56,3
45,9
81,6
74,3
67,2
62,0
57,6
46,7
83,9
76,2
68,8
63,5
58,9
47,6
86,2
78,1
70,4
65,0
60,2
48,4
88,5
80,0
72,1
66,4
61,5
49,2
90,8
81,9
73,7
67,9
62,8
50,1
93,0
83,8
75,3
69,3
64,0
50,9
95,3
85,6
76,9
70,8
65,3
51,7
97,6
87,5
78,5
72,2
66,6
52,5
99,8
89,3
80,1
73,6
67,8
53,3
102,0
91,2
81,7
75,0
69,0
54,0
104,3
93,0
83,3
76,4
70,3
54,8
106,5
94,8
84,8
77,9
71,5
55,6
108,7
96,6
86,4
79,3
72,7
56,3
110,9
98,4
87,9
80,7
73,9
57,1
113,1
100,2
89,5
82,0
75,1
57,9
115,3
102,0
91,0
83,4
76,3
58,6
117,5
103,8
92,6
84,8
77,5
59,4
119,7
105,6
94,1
86,2
78,7
60,1
121,9
107,4
95,6
87,6
79,9
60,8
124,1
109,2
97,1
88,9
81,1
61,6
126,3
110,9
98,6
90,3
82,3
62,3
128,5
112,7
100,2
91,6
83,5
63,0
130,6
114,4
101,7
93,0
84,6
63,7
132,8
116,2
103,2
94,3
85,8
64,4
135,0
117,9
104,7
95,7
87,0
65,1
137,1
119,7
106,1
97,0
88,1
65,8
139,3
121,4
107,6
98,4
89,3
66,5
141,4
123,1
109,1
99,7
90,4
67,2
143,6
124,9
110,6
101,0
94,6
67,9
145,7
126,6
112,1
102,4
92,7
68,6
147,9
128,3
113,5
103,7
93,9
69,3
150,0
130,0
115,0
105,0
95,0
70,0
Temperature graph calculation
The method for calculating the temperature graph is described in the reference book “Adjustment and operation of water heating networks” (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: T1, T3, T2, 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.
Temperature chart calculation table in MS Excel
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 T1
- design temperature in the return pipeline of the heating network T2
- design temperature in the heating system supply pipe T3
- Outdoor temperature Tn.v.
- Indoor temperature Tv.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.
Entering initial data into the temperature chart calculation table
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.
Graphic representation of the temperature graph
The table also calculates the temperature of direct network water taking into account wind speed.
Download temperature chart calculation
Coolant temperature depending on outside temperature
5/5 (3)
The coolant temperature directly depends on the outside temperature. You should pay attention to this fact. Weather conditions are directly taken into account when determining the required heating parameters.
In Russia, heating systems that operate on a water basis are most often used. However, the temperature of the water that flows through the batteries directly depends on weather conditions. Therefore, when it is cold outside, heat supply companies are obliged to increase the temperature regime, and when it is warm, on the contrary, to reduce it.
The schedule according to which the temperature of water supplied to the house is calculated is approved at the legislative level. It directly reflects the indicators at which the resource should be heated more intensely or weakly.
The schedule was developed based on approved standards for normal room temperature. Therefore, if it’s cold at home and the radiators don’t heat up, it’s the service provider’s fault. You can safely measure heat and draw up a report.
Thermal power plants do not calculate anything on their own. They do not have the right to assert their own norms. All indicators were approved by the Government of the Russian Federation in agreement with SanPiN. The basis is statistical data for the past ten years. When drawing up the graph, the highest and lowest thermometer marks for this period were taken into account.
However, such rules allow heat supply companies to save money on heating, since the highest temperature readings do not occur so often.
ATTENTION! Look at the completed sample application to the Criminal Code for measuring the temperature in the apartment:
The thermal level of water supplied for space heating must be at the level approved by the government. To calculate indicators, you do not need to resort to technical services. At the legislative level, everything has been calculated for a long time.
All that remains is to maintain the required temperature conditions at the inlet, outlet and in the heating system itself. However, to maintain balance, you need to have special knowledge that will help determine the intensity of water heating to increase or decrease its temperature.
Please note! In each region, heat supply companies are required to independently configure the equipment so that it produces water at the required temperature. This is due to the unique climatic conditions in different settlements.
For example, in the south of the country, external indicators never exceed -30 C, so they do not need to introduce increased operation of equipment.
In accordance with the approved rules, the temperature in the room should not be lower than +20C ... +22C. Such standards are considered optimal for living and spending time in an apartment.
The approved schedule contains information about the permitted water temperature:
- when leaving the heat supply station (boiler room);
- when in the heating system;
- when leaving the heating system, for example, when drawing from a tap directly into a heated apartment.
Each heat supply station must be equipped with special means that help maintain maximum and minimum values.
However, depending on the installation volume:
- large thermal power plants are required to equip the station with devices that produce water with a maximum temperature of 105°C to 130°C. The minimum indicator is 70°C;
- small stations and boiler houses are equipped with devices that produce water with a maximum temperature of 95°C to 105°C. The minimum indicator remains unchanged.
However, in some regions, maximum values are increasing due to a decrease in the average daily air temperature outside.
Previously, until 1991, the responsibility for drawing up the schedule rested with the local administration. Every year in the autumn-winter period they were engaged in calculations. Based on them, heating companies supplied heat to the house.
It cannot be said that such a method helped to find the optimal result. Some houses were cold in winter. However, this made it possible to optimize the temperature regime in many rooms. The majority of the population received the most comfortable living conditions.
note
Unfortunately, such calculation methods have been abolished. The rules have been introduced to simplify the payment system. However, this has resulted in poor service delivery. It seems that the heating company is not violating the law, but the house is still cold all winter.
The introduction of new rules led to a reduction in the costs of thermal power plants, rather than providing the population with sufficient heat.
Numerous complaints about public utilities from ordinary people did not go unnoticed. In 2010, the schedule of thermal indicators was again introduced. It is regulated by Federal Law No. 190 of July 27, 2010 “On Heat Supply”. Now the heat in the house has been restored again.
The new graph is based on average temperatures over the past ten years. The following are taken into account: the highest and lowest temperature of the thermometer in winter.
Attention!Our qualified lawyers will assist you free of charge and around the clock on any issues.Find out more here.
Outdoor temperature, °C
Water temperature at the heating system inlet, °C
Water temperature in the heating system, °C
Water temperature at the outlet of the heating system, in °C
8
+51…+52
+42…+45
+34…+40
7
+51…+55
+44…+47
+35…+41
6
+53…+57
+45…+49
+36…+46
5
+55…+59
+47…+50
+37…+44
4
+57…+61
+48…+52
+38…+45
3
+59…+64
+50…+54
+39…+47
2
+61…+66
+51…+56
+40…+48
1
+63…+69
+53…+57
+41…+50
65…+71
+55…+59
+42…+51
1
+67…+73
+56…+61
+43…+52
2
+69…+76
+58…+62
+44…+54
3
+71…+78
+59-…+64
+45…+55
4
+73…+80
+61…+66
+46…+57
5
+75…+82
+62…+67
+47…+59
6
+77-…+85
+64…+-69
+48…+62
7
+79…+87
+65…+71
+49…+61
8
+80…+89
+66…+72
+49…+63
9
+82…+92
+69…+-75
+50…+64
10
+86…+94
+71…+77
+51…+65
11
+86…+96
+72…+79
+52…+66
12
+88…+98
+74…+-80
+53…+68
13
+90…+101
+75…+82
+54…+69
14
+92…+103
+76…+83
+54…+70
15
+93…+105
+79…+86
+56…+72
16
+95…+107
+79…+86
+56…+72
17
+97…+109
+81…+88
+56…+74
18
+99…+112
+82…+90
+57…+75
19
+101…+114
+83…+91
+58…+76
20
+102-…+116
+85…+-93
+59…+77
21
+104…+118
+88…+94
+59…+78
22
+106…+120
+87…+96
+60…+80
23
+108…+123
+89…+97
+61…+81
24
+109…+125
+90…+98
+62…+82
25
+112…+128
+91…+99
+62…+83
26
+114…+130
+92…+101
+63…+84
27
+116…+134
+94…+103
+64…+86
28
+118…+136
+96…+105
+64…+87
29
+120…+138
+97…+106
+67…+88
30
+122…+140
+98…+108
+66…+89
31
+123…+142
+100…+109
+66…+90
32
+125…+144
+101…+111
+67…+91
33
+127…+146
+102…+112
+68…+92
34
+129…+149
+104…+114
+69…+94
A special schedule is developed for the boiler room of a thermal power plant, on the basis of which it operates. They serve residential apartment buildings, cottages, apartments, administrative buildings, municipalities and other premises.
The schedule makes it possible for thermal stations to prepare for the heating season. With it, the decrease in temperature is not dangerous for the population. In addition, it allows you to save thermal energy when you can heat the room in a reduced mode.
Heating temperature chart
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 has 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.
Temperature 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.
Temperature 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:
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 location and put into operation.
To ensure sufficient tightness of the flange connection, it is necessary to replace the paronite gaskets with rubber ones.
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.
Heat supply. Video
You can learn how the heat supply of private and apartment buildings works in 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.
Calculation of the temperature schedule for the supply of coolant to the heating system of residential buildings
A coolant is a special type of liquid or gaseous substance and is used to transfer thermal energy.
As a rule, water is used as a coolant.
The dependence of the temperature of the coolant in the heating system on the temperature indicators of the outside air is called a temperature graph.
The temperature of the coolant at the entrance to the heating system, under conditions of high-quality regulation of heat supply, is directly dependent on the atmospheric conditions outside the house.
The lower the values, the greater the temperature output must have a heating system coolant.
Temperature graph parameters are selected during the heating system design process and influence the choice of:
- heating appliance sizes;
- total coolant flow in the heating system;
- distribution pipeline sections(about compensators for polypropylene heating pipes is written here).
The temperature graph is indicated by two numbers that show the degree of heating of the coolant at the inlet and outlet.
Provided that this is enough to create an optimal, comfortable indoor microclimate.
The use of a graph is necessary in the process of setting up and analyzing the operating mode of heating systems.
Carrying out research allows us to determine the degree of heat consumption or, conversely, heat deficiency.
Main settings
The most significant parameter is the coolant temperature in the heating system, which determines the efficiency of heating the room.
It is also necessary to take into account the level of viscosity, the volume of thermal expansion and the optimal speed of the coolant, the minimum values of which are 0.2 m/s.
When choosing a coolant, you need to pay attention for the following characteristics:
- the speed of the coolant in the heating system (indicated here) and the transfer of the maximum volume of heat during the minimum time period and with low losses along the entire perimeter of the heating system;
- the liquid must not cause corrosive changes in the pipeline;
- viscosity indicators that affect the coolant speed and efficiency should be insignificant;
- the composition must not contain toxic or harmful substances;
- lack of flammability at too high temperatures.
The coolant should be affordable, and purchasing it for refills should not be difficult.
Expensive coolants, as a rule, are used for a longer time, and without replacement.
It should be noted that the temperature inside the room largely depends on the outside temperature and wind loads, as well as the degree of insulation and the sealing performance of the joints of the room.
Technical characteristics of radiators
In different rooms according to their purpose, the air temperature should be different.
Therefore, when determining the temperature schedule, it is necessary to focus on the following indicators:
- corner living space– 20оС;
- not a corner living space– 18oC;
- shower or bathroom– 25оС.
When the street temperature is minus 30°C and below, the indicators in the residential premises listed above should, accordingly, be increased to 22°C and 20°C.
In the following premises with large numbers of people, it is necessary to ensure:
- children's rooms– 18-23оС;
- children's pools– 30oC;
- walking verandas– 12оС;
- school premises– 21оС;
- bedrooms in a children's boarding school– 16oC;
- cultural institutions– 16-21оС;
- libraries– 18oC.
Temperature standards directly depend on the intensity of human movement indoors.
Therefore, in sports complexes the indicator should not exceed 18°C.
Outdoor temperature readings
The lower the street temperature, the greater the load the heating system in the room experiences. At zero street temperature, it is necessary to adhere to 40-45 ° C for supply and 35-40 ° C for outlet on radiator equipment. When using convectors, 41-49 ° C is supplied and 36-40 ° C is discharged
Timing of heating system
In single-pipe systems, the norm of temperature indicators is 105 ° C, and in the presence of a two-pipe system, the indicators are reduced to a level of 95 ° C. The difference in temperature indicators at the supply and outlet should be 105-70 ° C / 95-70 ° C
Supply of coolant to heating equipment
When using upper wiring for heating radiators, the difference should not exceed 2°C, and the presence of lower wiring requires a difference of 3°C
Type of heating device
Radiator equipment, compared to convectors, has an increased level of heat transfer
It is necessary to regulate the supply and removal of coolant in the heating system of residential, utility and other types of premises, depending on the street temperature.
Outdoor temperature indicators
Supply coolant temperature
Return coolant temperature
Zero temperature
40–45оС radiator41–49оС convector
35–38°C radiator 36–40°C convector
Minus 20oC
67–77оС radiator68–79оС convector
53–55оС radiator 55–57оС convector
Minus 40oC
95–105оС radiator and convector
79°C radiator and convector
Dependence on the type of operating fluids
Most often, water is used as a coolant (how a solenoid valve works is written here) or antifreeze for heating.
Running water contains a significant amount of foreign impurities that negatively affect the performance and service life of the heating system.
Therefore, it is advisable to use completely purified water or distillate:
- mass density indicators 1000 kg per cubic meter at a temperature of 4°C, with a decrease in specific density during heating;
- heat capacity level is 4.2 kJ/kg*C;
- boiling point 100oC with an increase under the influence of increased pressure.
Water is non-toxic and harmless, does not change properties when overheated, is affordable, is not limited by service life and can be combined with a pipeline made of any material.
Antifreeze is characterized by low temperatures freezing and contains ethylene glycol or propylene glycol.
Main advantage, compared to water, is represented by frost resistance:
- most species are characterized by toxicity;
- when overheated, foaming and the release of sediment are observed, settling on the walls of the heating equipment;
- high price, compared to water, and the impossibility of use in some types of pipelines;
- limited service life not exceeding five years under standard conditions of use.
To achieve maximum efficient heating of the room and obtain a long-lasting heating system, it is necessary to correctly calculate the coolant (a table of the volume of water in a steel pipe is published here).
Heating pipe section
Coolant volume in ml.
40 mm
1257
50 mm
2467
65 mm
3318
80 mm
5026
100 mm
7854
Standards for individual heating
In apartments equipped with autonomous heat supply, heating standards are represented by the heat transfer of heating devices to the area of the room where this device is installed, and are determined by the formula:
- P = S x H x 41,
- S– area of the room in square meters;
- N– height of the room in meters;
- 41 – coefficient of minimum thermal power.
The obtained value must be correlated with the indicators of the actual heat transfer of heating devices:
- cast iron radiator– 90-160 W;
- steel radiator– 60-170 W;
- aluminum and bimetallic radiator– 160-200 W.
Under conditions of lower connection, the standard thermal power of the radiator is reduced by 10%.
To connect a one-pipe system, Typically, such indicators decrease by 25-30%.
Heated floor system does not require heating the coolant to too high temperatures.
Therefore, return coolant can be used (approximate price for a check valve for water).
Under standard conditions, the heating standards of an autonomous system are calculated taking into account the type of heating devices and the actual level of coolant pressure inside the system.
We invite you to watch a video dedicated to creating the simplest automation for adjusting the degree of heating of the coolant in the “Warm Floor” system.
Temperature graph of heating networks for heating houses
In cities, almost all residential buildings are connected to a central heating system. To ensure comfortable living conditions in winter, it is necessary to control the temperature of the coolant supplied by thermal power plants and boiler houses. To do this, heating network employees develop a temperature schedule, depending on the climatic conditions of the region and the outside air temperature.
To make the premises comfortable, you need to develop a temperature schedule
Purpose and scope
The temperature graph of the heating network displays the required temperature of the coolant in accordance with the same indicator of the outside air. He used in central heating systems, allowing you to maintain the required temperature in the premises and save energy resources.
The graph can also be used in autonomous heating systems.
With its help, it not only creates the desired temperature in the room, but also ensures the safe operation of the heating system.
It should be noted that the choice of all parameters of the equipment used to heat the apartment depends not only on the climatic characteristics of the region, but also on the temperature schedule.
Thus, it shows what the coolant temperature should be depending on the outside temperature.
Main types
There are several types of temperature graphs, each of which affects the standard temperature of heating radiators. The choice of a specific type depends on several factors. The most important among them are:
It is customary to distinguish graphs for two- and one-pipe heating systems, consisting of two numbers. For example, a temperature graph of 150-70 means that in order to maintain comfortable conditions in the apartment, the temperature of the coolant entering the system should be 150 degrees, and the return temperature should be 70 degrees.
Features of compilation
When developing schedule indicators, it is necessary to focus on the capabilities of the heating system, the characteristics of the heat generator, as well as temperature fluctuations outside. If there are sharp changes in temperature in the region, then it is necessary to select the correct pipe material and fuel.
When choosing the optimal temperature, several factors are most often taken into account:
Each room has its own level of comfortable temperature
Depending on the type of heated room, the standards provide for different temperature parameters. If for the housing stock this figure is 18 degrees, then for hospitals and children's institutions it is 3 degrees higher.
For rational use of fuel, this difference should be minimal. To solve the problem, it is necessary to carry out additional work to insulate not only the heating main, but also the building. Any building radiates heat into the environment. This factor must be taken into account when designing heating systems.
Temperature regulation
Employees of heating networks and thermal power plants are responsible for the parameters of the heating main, and the temperature indicators inside the buildings are in the department of the housing office. To regulate the room temperature during the heating season, two methods can be used.
The first is called quantitative and involves a change in water flow at constant temperatures. If a qualitative method is used, then the volume of coolant consumed remains constant, but its thermal parameter changes.
It is the second option that is used most often, as it is the most economical. A high-quality method of heat regulation allows you to provide comfortable living conditions even with sudden changes in temperature outside.
For a heat energy consumer, knowledge of coolant supply standards can be useful.
note
This is due to the fact that if the schedule parameters are not observed, a recalculation for utilities may be required. To measure the thermal index of the coolant, it is not necessary to install complex heat metering devices in the apartment.
It is enough to drain a small amount of water from the radiator into a container and then take a measurement.
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 a centralized system, drawing up a correct temperature schedule for the heating boiler room is required to ensure optimal comfortable temperature in apartments. The main problem is the lack of feedback - it is impossible to adjust the parameters of the coolant depending on the degree of heating of the air 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
It is often not necessary to make similar calculations for autonomous heating systems in a private home. 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 packages. 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 the correct selection of 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:
The temperature graph represents the dependence of the degree of heating of water in the system on the temperature of the cold outside air. After the necessary calculations, the result is presented in the form of two numbers. The first means the water temperature at the entrance to the heating system, and the second at the exit.
For example, the entry 90-70ᵒС means that under given climatic conditions, to heat a certain building, the coolant at the entrance to the pipes will need to have a temperature of 90ᵒС, and at the outlet 70ᵒС.
All values are presented for outside air temperature for the coldest five-day period. This design temperature is accepted according to the joint venture “Thermal protection of buildings”. According to the standards, the internal temperature for residential premises is 20ᵒС. The schedule will ensure the correct supply of coolant to the heating pipes. This will avoid overcooling of the premises and waste of resources.
The need to perform constructions and calculations
A temperature schedule must be developed for each locality. It allows you to ensure the most competent operation of the heating system, namely:
- Bring heat losses during the supply of hot water to houses into line with the average daily outside air temperature.
- Prevent insufficient heating of rooms.
- Oblige thermal stations to supply consumers with services that meet technological conditions.
Such calculations are necessary both for large heating stations and for boiler houses in small towns. In this case, the result of calculations and constructions will be called a boiler room schedule.
Methods for regulating temperature in a heating system
Upon completion of the calculations, it is necessary to achieve the calculated degree of heating of the coolant. This can be achieved in several ways:
- quantitative;
- quality;
- temporary.
In the first case, the flow of water entering the heating network is changed; in the second, the degree of heating of the coolant is adjusted. The temporary option involves a discrete supply of hot liquid to the heating network.
For a central heating system, the most characteristic is a high-quality method, in which the volume of water entering the heating circuit remains unchanged.
Types of charts
Depending on the purpose of the heating network, the implementation methods differ. The first option is a normal heating schedule. It represents constructions for networks that operate only for space heating and are centrally regulated.
The increased schedule is calculated for heating networks that provide heating and hot water supply. It is built for closed systems and shows the total load on the hot water supply system.
The adjusted schedule is also intended for networks operating for both heating and heating. This takes into account heat losses as the coolant passes through the pipes to the consumer.
Drawing up a temperature chart
The drawn straight line depends on the following values:
- normalized indoor air temperature;
- outside air temperature;
- degree of heating of the coolant when entering the heating system;
- degree of heating of the coolant at the exit from the building networks;
- degree of heat transfer from heating devices;
- thermal conductivity of external walls and total heat losses of the building.
To perform a competent calculation, it is necessary to calculate the difference between the water temperatures in the forward and return pipes Δt. The higher the value in a straight pipe, the better the heat transfer of the heating system and the higher the indoor temperature.
In order to rationally and economically use the coolant, it is necessary to achieve the minimum possible value of Δt. This can be achieved, for example, by carrying out work on additional insulation of the external structures of the house (walls, coverings, ceilings above a cold basement or technical underground).
Heating mode calculation
First of all, it is necessary to obtain all the initial data. Standard values of external and internal air temperatures are adopted according to the joint venture “Thermal protection of buildings”. To find the power of heating devices and heat losses, you will need to use the following formulas.
Heat losses of the building
The initial data in this case will be:
- thickness of external walls;
- thermal conductivity of the material from which the enclosing structures are made (in most cases indicated by the manufacturer, denoted by the letter λ);
- surface area of the outer wall;
- climatic region of construction.
First of all, find the actual resistance of the wall to heat transfer. In a simplified version, it can be found as the quotient of the wall thickness and its thermal conductivity. If the outer structure consists of several layers, find the resistance of each of them separately and add the resulting values.
Thermal losses of walls are calculated using the formula:
Q = F*(1/R 0)*(t indoor air -t outdoor air)
Here Q is the heat loss in kilocalories, and F is the surface area of the external walls. For a more accurate value, it is necessary to take into account the glazing area and its heat transfer coefficient.
Battery Surface Power Calculation
Specific (surface) power is calculated as the quotient of the maximum power of the device in W and the heat transfer surface area. The formula looks like this:
P ud = P max /F act
Coolant temperature calculation
Based on the obtained values, the heating temperature regime is selected and a direct heat transfer line is constructed. The values of the degree of heating of the water supplied to the heating system are plotted on one axis, and the outside air temperature on the other. All values are taken in degrees Celsius. The calculation results are summarized in a table in which the nodal points of the pipeline are indicated.
Carrying out calculations using this method is quite difficult. To perform competent calculations, it is best to use special programs.
For each building, this calculation is performed individually by the management company. To approximately determine the water entering the system, you can use existing tables.
- For large heat energy suppliers, coolant parameters are used 150-70ᵒС, 130-70ᵒС, 115-70ᵒС.
- For small systems for several apartment buildings, the following parameters are used: 90-70ᵒС (up to 10 floors), 105-70ᵒС (over 10 floors). A schedule of 80-60ᵒC can also be adopted.
- When installing an autonomous heating system for an individual home, it is enough to control the degree of heating using sensors; you don’t need to create a schedule.
The measures taken make it possible to determine the parameters of the coolant in the system at a certain point in time. By analyzing the coincidence of the parameters with the graph, you can check the efficiency of the heating system. The temperature chart table also indicates the degree of load on the heating system.