The examples of calculations of the cost of hot water and thermal energy given by the employees of the REC, although they are largely conditional, nevertheless show that the presence of a metering device allows you to pay according to actual consumption. Calculation according to the standards is almost always an overpayment.
It should be noted that hot water supply can be centralized and non-centralized.
Non-centralized water supply is the preparation of hot water in intra-house autonomous systems engineering support. For example, when a boiler or instantaneous water heater is installed in a private house.
Only centralized hot water supply is subject to regulation (tariff setting). In this regard, a distinction is made between open and closed hot water supply schemes.
open circuit
With an open (centralized) heat supply scheme, the selection of hot water for the needs of hot water supply occurs directly from the heating network.
In accordance with the current legislation, a two-component tariff is set for hot water in an open system, which consists of a component for a heat carrier and a component for thermal energy.
The heat energy component is set by the regulator as a single-rate or two-rate component equal to the one- or two-rate heat tariff, respectively.
The component for the heat carrier (and for public utilities it is, as a rule, water that has undergone additional treatment at the boiler house) is set as a single-rate component and is taken equal to the tariff for the heat carrier.
An example of calculating the payment for hot water in the presence of an in-house meter
Data for calculation:
consumption volume 5 cubic meters.
The payment for hot water supply provided in the specified apartment will be: 5.0 * 89.38 = 446.90 rubles.
Calculation of the amount of payment for hot water supply in an open heat supply system provided in a residential building in the absence of an internal metering device(if it is technically possible to establish it) is determined based on the consumption standard, the number of people living in a residential building (registered) and the tariff for hot water.
An example of calculating the payment for hot water in the absence of an in-house meter
The apartment building is located in the city of Omsk, the supplier of thermal energy is JSC Omsk RTS through the networks of the MP of Omsk "Thermal Company".
Data for calculation:
consumption standard in the amount specified in Appendix No. 1 of the Order of the Regional Energy Commission of the Omsk Region dated September 11, 2014 No. 118/46 for 5-storey buildings, 3.4 cubic meters. m / sq. m (in the absence of technical feasibility of installing individual hot water metering).
two-component tariff for hot water, approved by order of the REC of the Omsk region dated December 19, 2016 No. 597/71, from January 1, 2017 in the following amount:
Convert to single component using the following formula:
17.82 + 1422.60 * 0.0503 \u003d 89.38 rubles / cubic meter m;
where 0.0503 Gcal / cu. m - the standard amount of thermal energy for the preparation of one cubic meter of hot water.
Number of residents - 3 people.
The payment for hot water supply provided in the apartment will be: 3.4 * 89.38 * 3 = 911.68 rubles.
Important ! If the apartment does not have a metering device, if there is a technical possibility for its installation, a multiplying factor is applied in the calculation, which from January 1, 2017 is 1.5.
The fee in the above apartment, taking into account the multiplying factor, will be 3.4 * 1.5 * 89.38 * 3 = 1367.51 rubles.
Currently, in accordance with federal legislation, there is a phased transition from an open hot water supply system to a closed one.
closed circuit
With a closed (centralized) hot water supply system, hot water from the heating network is used exclusively for heating, and hot water supply is provided through a separate circuit or is carried out by heating tap drinking water in central heating points (CHPs).
In accordance with the current legislation, tariffs for hot water in closed system hot water supply are set in the form of two-component tariffs, consisting of a component for cold water and a component for thermal energy.
The component for cold water is equal to the established tariff for cold water, the component for thermal energy is equal to the established tariff for thermal energy.
The amount of payment for the utility service for hot water supply is determined in accordance with the Rules for the provision of utility services to owners and users of premises in apartment buildings and residential buildings, approved by Decree of the Government of the Russian Federation dated May 6, 2011 No. 354, according to the formula No. 24.
An example of calculating the payment for hot water in a closed hot water supply system with an in-house meter
Data for calculation:
the volume of consumption in the apartment is 5 cubic meters.
The payment for the hot water service in the first half of 2017 in the specified apartment will be:
14.63 * 5+ (5 * 0.0503) * 1422.60 \u003d 430.93 rubles.
An example of calculating the payment for hot water in a closed hot water supply system in the absence of an in-house meter
The apartment building is located in the city of Omsk, the supplier of hot water is the MP of Omsk "Thermal Company" from the heat sources of JSC "Omsk RTS".
Data for calculation:
consumption standard according to Appendix No. 1 of the Order of the Regional Energy Commission of the Omsk Region dated September 11, 2014 No. 118/46 for 5-storey buildings - 3.4 cubic meters. m/person
two-component tariff for hot water, approved by order of the REC of the Omsk region dated December 20, 2016 No. 623/72, from January 1, 2017 in the following amount:
The payment for the hot water service from 1 person in the first half of 2017 in the specified apartment will be:
14.63 * 3.4 + (3.4 * 0.0503) * 1422.60 \u003d 293.03 rubles.
If the apartment does not have a metering device, if there is a technical possibility for its installation, a multiplying factor is applied in the calculation, which from January 1, 2017 is 1.5.
The payment for the hot water service from 1 person living in the above apartment, taking into account the increasing coefficient, will be 1.5 * 293.03 = 439.55 rubles.
Infographic provided by the REC of the Omsk region
It is impossible to live and work without water. There are many places on Earth where there is a shortage of this essential resource. Russia has many rivers and many natural reservoirs of fresh water. But at the same time, all the same, it is necessary to save this expensive moisture. To do this, our authorized bodies signed a law that requires all property owners to install cold and hot water meters in their homes. The presence of these devices makes it possible to use resources sparingly, which is facilitated by the established water tariffs. Consumption rates, according to which utility bills are calculated, are quite expensive. The standard for cold water supply is set at 6.96 cubic meters per person, and for hot water - 3.49 cubic meters.
Water consumption rates: the benefits of accounting
After the installation of metering devices, the real consumption, although it will remain the same, it is possible to reduce the cost of water by half. But there are categories of citizens who do not benefit from control over water supply. This applies to people who are not registered in the apartment, but live there and use all the utilities provided. When calculating payments, they are not taken into account, and the resources used are divided among all residents of an apartment building, which makes common house expenses much more expensive.
Also, negligent residents, using various devices, which is fraud, reduce payment for water. In this case, the burden of payments falls on other apartment owners who honestly pay. Therefore, it is necessary to deal with such citizens, bringing them to clean water and forcing them to pay for all the services used.
Effective from the beginning of summer 2016 Decree No. 603, which changed the conditions for the provision of housing and communal services. Citizens who did not install meters for water supply in their apartments or did not carry out verification within the recommended period, the calculation of cold and hot water will be made more by forty percent.
What is the price of a cubic meter
The cost of a cube of water differs in different areas of our country. It is regulated at the state and regional level by the relevant authorities. The price list is subject to the following conditions:
- water intake method;
- electricity costs for this;
- cleaning methods;
- maintenance and repair of pipelines;
- salary expenses;
- heating costs.
- payment standards are calculated in ruble terms and are based on the price per cubic meter;
- the tariff rate includes the nominal price of water.
The price of hot water consists of the following factors:
- energy supply, which was spent on heating water (when calculating, the amount of heat used per one cubic meter of cold water is taken into account;
- the cost of 1 cubic meter of cold water, which is heated to get hot.
Water tariffs
To the question of how much a cube of received water costs according to the meter and without it in the current year, the answer is simple - it is equivalent. The meter does not affect the price per cubic meter in any way.
Since July 2017, the tariff for supplied cold water has been set at 33 rubles 3 kopecks, and for 1 cubic meter of hot water the fee is 143 rubles 76 kopecks. A cheaper resource in Krasnoyarsk - m 3 of cold water costs 18 rubles 16 kopecks, hot is more expensive - 176 rubles 44 kopecks. In comparison with the beginning of the year, the cost of cold water according to the meter has risen in price by 7.2 percent, and hot water by 10.6 percent.
Calculation of the price per cubic meter
For buildings where metering devices are not installed, the amount of heat Q Gcal / m 3 for heating one cubic meter of cold water supply with a temperature of T2 - 8 degrees to a temperature of T1 - 59 degrees must be calculated using the following formula:
Q \u003d C x Px (T1-T2) x (1 + K)
where With is the specific heat capacity of the liquid, and R – volume weight liquids.
In a building with metering devices, at the end of the billing period, readings are taken from the input riser and the water consumption is determined based on the tariffs for hot water supply. For example, 90 Gcal of heat energy and 1000 cubic meters of hot water were spent in the building. Divide 90 by 1000. You get 0.09 Gcal / cubic meter.
The price for water in bills
In order to find out how much a cube of supplied cold water costs, you need to view. In the line of cold water, the volume of consumption for a month is indicated in cubic meters. Then see if this figure is similar to the meter readings provided to the settlement center. If the numbers match, then the second line will contain the price of cold water per cubic meter. If you multiply these readings, you get how many cubic meters of water have been consumed in accordance with metering devices. The cost per cubic meter of hot water is also calculated. If there are two flow meters in a residential area, then the indicators taken from them are added up.
In addition, it should be borne in mind that the question of how much a cube of hot and cold water costs is also influenced by which one provides services to the population. A water utility or other organization is indicated on the receipt for water consumption. The government allows raising the price of utility bills only as part of the inflationary situation in the country.
In 2017, lines for water expenses common to the whole house were removed from the payments that come to owners and tenants of housing. At the same time, general house expenses for hot water and cold water are included in the line for payment for residential premises. When you need to calculate the cost of water supply, then these expenses are also taken into account. The cost of supplying resources for common areas, which includes average water consumption, is divided by all dwellings in an apartment building, taking into account their footage. At the same time, the additional price grows quite strongly. To reduce payments on receipts, you need to find tenants who live in apartments without registration and force them to pay for water in accordance with current regulations. It is necessary for all tenants and property owners to be conscientious payers and provide indicators from metering devices regularly on the dates specified for this. You should also check the flow meters, for which you should contact the water utility or other similar structures.
How much to pay when there is no hot water in the building
It greatly affects how much a cubic meter costs, the lack of hot water in a residential building. In some buildings, there is no DHW circulation due to poor pressure or when there are no return networks. Due to these factors, the heating network is not able to provide the required temperature in the centralized system. In order for really heated water to flow from the tap, you have to wait a long time at the open mixer.
As a result, the cost of an actual cubic meter of hot water becomes more expensive due to the fact that its volume is growing. People pay at the same time on the counters much more. When the reverse network is restored or a circular pump equipment, water from the mixer begins to flow the desired heating - 60 degrees. It is diluted with cold water so as not to burn. At the same time, the calculation of the cost of the provided hot water is reduced to the minimum amounts, because cold water supply and sewerage cost much less than hot water.
Benefits for water services
When asked how much 1 cubic meter of water received by the meter costs, you need to take into account. They are provided to veterans of labor activity, people with disability established by the ITU and participants in the Second World War. They pay the cost of water per person less than fifty percent.
Low-income citizens, those who have a salary less than the cost of living, and people whose utility bill is more than the approved interest rate from the joint income of the family, receive subsidies for utilities. To apply for it, you need to contact the local social security authorities with registration documents, income statements and utility bills.
Flowmeter verification
All hot and cold water meters are sent for verification within the recommended time frame. For DHW devices, this is four years, and for cold water flow meters, six years. The terms are counted from the moment of production of the devices. Today, flowmeters are verified without dismantling from risers; for this, a specialist comes and performs verification on site.
Quality of water supply
Water supply is carried out according to certain parameters, which are established by special standards. For cold water it is 0.03-0.06 MPa, and for hot water it is 0.03-0.45 MPa. If the pressure does not correspond to these figures, then a booster pump is installed.
A high tariff for wastewater disposal and water supply should be directly dependent on the quality indicators of the supplied resources. Unfortunately, such parameters are low in our country, this is due to polluted natural water basins, a small number of treatment devices, old technologies and worn out pipes. centralized systems resource supply. Many regions cannot boast of compliance with the standards for the content of salts and heavy metals. There are also places where the water contains harmful microorganisms and poor organoleptic indications.
In our country, water purification with chlorine is still used today, which is harmful to public health - this has been proven by many human studies. leaves much to be desired, it has a bad color and smell. For control, it is necessary to create a program to improve water indicators in accordance with international standards. This will provide clean and harmless moisture to all apartments.
Differences in tariffs with and without a meter
Since 2014, two-component tariffs for hot water have been in effect. Now the cost is made up of the price per cubic meter plus the cost per Gcal of heat. At the same time, government authorities plan no differences in the calculation for 1 cubic meter of water with and without a flow meter. The cost of one m 3 is the same, but it is calculated differently. For water without a meter, you will have to pay for the standard per person. The new tariffs are multiplied with the number of people living in the apartment, after which the final payment for a cubic meter of water is calculated.
With metering devices, only the water spent by residents is counted, despite their quantity. However, in this situation, it is necessary to add on the overspending of the spent resources of the whole house, which is scattered on all the owners who installed the counters. In practice, payments for water resources are made in accordance with individual flow meters, and the excess consumption of cubic meters is checked once a year, after which corrective receipts are sent, which are calculated according to the following formula:
- The volume of the resource provided to the residential building is summed up in accordance with the readings of individual flow meters and the amount of water spent by residents without metering devices, which is calculated according to current standards.
- The volume of water, according to the indications of a common house meter, is divided by the result obtained.
- The result obtained is multiplied by the indicators of the individual flow meter of each dwelling.
- The amount received is multiplied by the approved tariffs for hot and cold water.
Resource overrun happens mainly due to the following reasons:
- exorbitant water consumption in apartments without installed meters;
- water leaks due to malfunctions and emergencies inside centralized water supply systems;
- unauthorized connection of illegal consumers to the network (for example, for watering adjacent territories);
- use of water supply by unregistered users.
In connection with all these features, the difference between the indicators of general house flow meters and individual meters is paid by the owners of the latter. In such a situation, the installation of a resource consumption device may be unprofitable, therefore, all citizens were obliged to install individual flow meters in apartments.
Tariff growth
Payment for cold water and others. The current situation in Russia is forcing companies that supply utilities to increase utility rates. However, it should be noted that these figures are growing much lower than planned by the country's government. And although the burden on all consumers is increasing, experts see no other way out of the current post-Soviet conditions.
A fifth of the population of Russia generally believes that the consumption rate is too high and it is not necessary to pay for water resources in such a rich country. But everything around is growing in price, so the increase in tariffs is inevitable and justified by the current economic situation. It should also be said that the increase in tariff rates will not cover the cost of restoration and replacement of pipelines.
Since the beginning of 2017, they have been used for the supply of basic resources (cold and hot water, electricity). But this only applies to citizens who have not installed metering devices in their apartments. For people who good reasons they cannot establish them (which is proved by the relevant act), the conditions do not change, they pay for the received cubic meters in accordance with the norms for spending on hot and cold water, without increasing coefficients.
The main problem of the population that receives hot and cold water supply is how to prevent the growth of payments? The solution is quite simple - you need to install individual meters in the housing, which take into account all the costs of housing and communal services. It is also necessary to install a flow meter common to the entire building. In such a situation, the multiplying factor is not applied, because the payment is calculated in accordance with the actual readings of the instruments.
findings
The price of a cubic meter of cold and hot water is made up of many conditions. To control the creation of prices for these resources, you need to fully decipher all the costs from which the price per cubic meter is determined. The flow meters installed in the apartments teach property owners to save and conserve natural resources. And when hot water circulates in accordance with the norms, this lowers its price. Installation of common house metering devices helps to reduce cash costs and with high precision find out the amount of energy for heating one cubic meter of water.
Of course, installing water meters helps save money. Most residents believe that the installation of such devices is economically feasible.
In contact with
How to correctly calculate the readings from the meters?
So, the meters in the apartment are installed. To calculate the volume of water consumed for a certain period (month), look at the receipt for paying for the apartment for the last month and write off the last readings from it.
Some management companies now enter this figure directly into the payment document. If this is your first payment after installing water meters, the previous figure is zeros.
Now we are learning to take accounting readings. The scale of modern counters gives us 8 digits. The first five of them are black, and the last 3 are red.
Since the corresponding columns of the payment document reflect the number of spent cubes of either cold or hot water, then pay attention to the black indicators. They need to be written on the receipt. Indicators of red numbers - liters of water spent by your family, are not indicated.
Accounting readings of the water meter are taken at the end of each billing period (month). The meter data can be transferred by phone or via the Internet (in an electronic document) to a specialized organization.
Note: when transmitting water readings on the meter, the numbers that your meter is currently showing, as well as the previous value, which is written on the receipt for the last month, are indicated.
Legal justification for charging for water supply
Management companies count water by meters, based on Decree of the Government of the Russian Federation No. 354, adopted on 05/06/2011 and in force since the fall of 2012 and still.
These legislative Rules, in comparison with the old ones, are fairer, but still far from perfect.
Payment for water by meters now consists of several terms, while taking into account:
- The reading of the scale of the meter located in a certain apartment, set to calculate the amount of cold resource consumed this month.
- The reading of the rock of the counter located in a certain apartment, set to calculate the amount of hot resource consumed this month.
- Readings of the device installed in your home (in basement) set to calculate the amount of spent cold resource by all tenants.
- Readings of the device installed in your house (in the basement), installed to calculate the amount of hot resource spent by all residents.
- Share consisting of your apartment in the house. It is taken into account when determining the amount spent on the needs of the whole house (the so-called "common house needs").
- The share that your apartment in the house corresponds to. It is also taken into account when determining the hot water spent on the needs of the whole house (the same so-called "common house needs").
The first two components of the list are the consumed water resource, the volume of which depends only on you and the size of your family's needs. The remaining items are made up of the actual needs of the whole house, for example, wet cleaning of stairs and apartment areas.
And the “lion’s” share of common house expenses is overspending, formed from riser leaks, unscrupulous tenants who incorrectly indicate the cubes they spent or live in the house, use communications, but are not registered at the place of residence.
How to calculate water charges
It is possible to calculate the costs associated with water consumption by multiplying its volume spent by the corresponding tariff indicators in a particular locality.
According to the volumes of water consumption indicated by you, according to the indications of apartment meters, the cost of payment for the water disposal service, which provides for the removal of wastewater, is also calculated.
Helpful information: you can find out the tariff rates established and relevant for today by calling your management company. The same information may be contained in payment document.
Calculation of common house costs for cold water
This value is calculated quite difficult, using formulas that do not make sense to indicate. We only note to calculate this size take into account:
- The amount in cubes of cold water that was spent by consumers over a certain period, if common house water meters are installed in the house, this takes into account the volume spent by both residents and those who own non-residential premises.
- Hot water, which for a certain period was spent by consumers, if the house has common house water meters, this takes into account the volume spent by both residents and owners of non-residential premises.
- The amount in cubic meters of cold water used for a type of utility such as heating.
- The area of all rooms in your house, meaning both residential apartments and non-residential ones.
- The area of the apartment that you use in this house.
So, given formula involves calculating the overspending of the resource used in comparison with the calculated norms for your home.
As mentioned above, overspending usually includes:
- Possible leak from riser pipes.
- Water use by non-registered residents.
- "Cunning" of neighbors indicating the wrong number of cubes in the payment.
In accordance with the Rules specified in the article, the owners of apartments and non-residential premises will pay for the overused water, in proportion to the occupied area.
Calculation of general house costs for hot water
There is a similar formula to help calculate the overused hot water. The same values are taken into account, only those relating to the supply of hot water.
However, our Government took care of citizens burdened with utility bills, and in 2013 established consumption rates for general household needs.
These norms curb the "appetite" of management companies and are developed independently at the local level. To find out their values, contact your management company in writing.
Limits for common house needs
According to paragraph 44 of the Decree of the Government of the Russian Federation of April 16, 2013, the volume of general house needs (ODN) should not exceed the standard consumption established by local authorities.
It does not have the ability to bill you for the amount of general house consumption that exceeds the established standard.
Again, if the contract for water supply is not concluded with a resource supply company, for example, with Vodokanal. If there is an agreement with the latter, ODN will be paid in full.
In conclusion, I would like to draw your attention to the fact that some settlements set a fixed minimum payment that must be paid, regardless of whether you actually spent it or not.
This takes into account that in the event of an overpayment in a certain month for actually not spent, in the next reporting period this overpayment will be offset. And this is fair.
If you are not a resident of a high-rise building, but own a house in the village, remember that payment is calculated in a similar way, according to the current water supply tariff.
See video lesson how to take readings of water meters correctly:
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The calculation of hot water supply systems consists in determining the diameters of the supply and circulation pipelines, selecting water heaters (heat exchangers), heat generators and heat accumulators (if necessary), determining the required pressure at the inlet, selecting booster and circulation pumps, if necessary.
The calculation of the hot water supply system consists of the following sections:
The estimated costs of water and heat are determined and, on the basis of this, the power and dimensions of the water heaters.
The supply (distribution) network is calculated in the drawdown mode.
The hot water supply network is calculated in circulation mode; the possibilities of using natural circulation are determined, and if necessary, parameters are determined and circulation pumps are selected.
In accordance with the individual task for the course and diploma design, the calculation of storage tanks, the coolant network can be made.
2.2.1. Determination of the estimated costs of hot water and heat. Selection of water heaters
To determine the heating surface and further selection of water heaters, hourly flow rates of hot water and heat are required, for calculating pipelines - second flow rates of hot water.
In accordance with clause 3 of SNiP 2.04.01-85, the second and hourly consumption of hot water is determined by the same formulas as for cold water supply.
The maximum second flow of hot water in any calculated section of the network is determined by the formula:
- second consumption of hot water by one device, which is determined by:
a separate device - according to mandatory Appendix 2;
various devices serving the same consumers - according to Appendix 3;
various devices serving various water consumers - according to the formula:
, (2.2)
- second consumption of hot water, l / s, by one water-folding device for each consumer group: taken according to Appendix 3;
N i is the number of water folding devices for each type of water consumer;
- the probability of operation of devices, determined for each group of water consumers;
a - coefficient determined according to Appendix 4, depending on total number devices N in the network section and the probability of their action P, which is determined by the formulas:
a) with the same water consumers in buildings or structures
,
(2.3)
where 
- the maximum hourly consumption of hot water in 1 liter by one water consumer, is taken according to Appendix 3;
U - the number of hot water consumers in a building or structure;
N is the number of devices served by the hot water supply system;
b) with different groups of water consumers in buildings for various purposes
, (2.4)
and N i - values related to each group of hot water consumers.
The maximum hourly consumption of hot water, m 3 / h, is determined by the formula:
,
(2.5)
- hourly consumption of hot water by one device, which is determined by:
a) with identical consumers - according to Appendix 3;
b) for different consumers - according to the formula
, l/s (2.6)
and 
- values related to each type of hot water consumer;
magnitude 
is determined by the formula:
, (2.7)
- coefficient determined according to Appendix 4, depending on the total number of devices N in the hot water supply system and the probability of their action P.
Average hourly hot water consumption 
, m 3 / h, for the period (day, shift) of maximum water consumption, including, is determined by the formula:
, (2.8)
- the maximum daily consumption of hot water in 1 liter by one water consumer, is taken according to Appendix 3;
U is the number of hot water consumers.
The amount of heat (heat flow) for the period (day, shift) of maximum water consumption for the needs of hot water supply, taking into account heat losses, is determined by the formulas:
a) within the maximum hour
b) during the average hour
and 
- maximum and average hourly consumption of hot water in m 3 / h, determined by formulas (2.5) and (2.8);
t s is the design temperature of cold water; in the absence of data in the building, t is assumed to be + 5ºС;
Q ht - heat loss by the supply and circulation pipelines, kW, which are determined by calculation depending on the lengths of the pipeline sections, the outer diameters of the pipes, the temperature difference between hot water and the environment surrounding the pipeline and the heat transfer coefficient through the pipe walls; while taking into account the efficiency of pipe insulation. Depending on these values, heat losses are given in various reference manuals.
When calculating in course projects, heat loss Q ht by supply and circulation pipes can be taken in the amount of 0.2-0.3 of the amount of heat required to prepare hot water.
In this case, formulas (2.9) and (2.10) will take the form:
a), kW (2.11)
b) , kW (2.12)
A smaller percentage of heat loss is accepted for systems without circulation. In most civil buildings, fast sectional water heaters with variable performance are used, i.e. with adjustable heat carrier consumer. Such water heaters do not require heat storage tanks and are calculated for the maximum hourly heat flow. 
.
The selection of water heaters consists in determining the heating surface of the coils according to the formula:
, m 3 (2.13)
K - heat transfer coefficient of the water heater, taken according to table 11.2; for high-speed water-to-water heaters with brass heating tubes, the value of k can be taken in the range of 1200-3000 W / m2, ºС, and the smaller one is accepted for devices with smaller section diameters;
µ - coefficient of reduction of heat transfer through the heat exchange surface due to deposits on the walls (µ=0.7);
- estimated temperature difference between the coolant and heated water; for counterflow instantaneous water heaters 
º is determined by the formula:
, ºС (2.14)
Δt b and Δt m - greater and lesser temperature difference between the coolant and the heated water at the ends of the water heater.
The parameters of the coolant in the winter settlement period, when the heating networks of buildings are operating, are taken in the supply pipeline 110-130 ºС and in the reverse -70, the parameters of the heated water during this period t c \u003d 5 º C and t c \u003d 60 ... 70 ºC. AT summer period the heating system works only for the preparation of hot water; the parameters of the heat carrier during this period in the supply pipeline are 70…80 ºC and in the return pipeline 30…40 ºC, the parameters of the heated water and t c = 10…20 ºC and and t c = 60…70 ºC.
When calculating the heating surface of a water heater, it may happen that the summer period will be decisive, when the temperature of the heat carrier is lower.
For storage water heaters, the calculation for the temperature difference is determined by the formula:
, ºC (2.15)
t n and t k - initial and final temperature of the coolant;
t h and t c - temperature of hot and cold water.
However, storage water heaters are used for industrial buildings. They take up a lot of space, in these cases they can be installed outdoors.
The heat transfer coefficient for such water heaters, according to table 11.2, is 348 W / m 2 ºC.
The required number of standard sections of water heaters is determined:
, pcs (2.16)
F is the calculated heating surface of the water heater, m 2;
f - heating surface of one section of the water heater, taken according to Appendix 8.
The pressure loss in an instantaneous water heater can be determined by the formula:
, m (2.17)
n - coefficient taking into account the overgrowth of tubes, is taken according to experimental data: in their absence during one cleaning of the water heater per year n=4;
m is the coefficient of hydraulic resistance of one section of the water heater: with a section length of 4 m m=0.75, with a section length of 2 m m=0.4;
n in - the number of sections of the water heater;
v - speed of movement of heated water in the tubes of the water heater without taking into account their overgrowth.
, m/s (2.18)
q h - maximum second water flow through the water heater, m/s;
Wtotal - the total area of the active section of the water heater tubes is determined by the number of tubes, taken according to Appendix 8 and the diameter of the tubes, taken 14 mm.