How cold water is calculated by the meter. The cost of a gcal of heat and a cube of hot water according to the meter

In accordance with the new legislation, apartments in houses must be equipped with water meters. But even if you do not follow the instructions of the law, then the installation of water metering equipment - optimal solution. It will allow rational use of water and on this. The result will be noticeable on the payment document with next month. For those who have not encountered such metering devices, you should know how to take readings from a water meter, what numbers to write when filling out documents. This information will be relevant for residents who are not doing this for the first time. An error in taking readings can lead to problems.

How to take water meter readings

In the apartments, two water meters are installed: for cold and hot. In order to easily distinguish the counters, they are painted in blue and red colors. Accordingly, the blue counter is for cold water, it is installed on lower part pipes. Red - for hot, this counter is most often placed on top.

If you are not sure if the appliances were installed correctly, then there is an easy way to check. It is necessary to open the tap with cold or hot water and see which of the counters has started work. After making sure that their work is correct and having determined where which meter is, you can begin to solve the question “how to take readings from water meters”.

Taking water meter readings: how to distinguish meters

Water meters contain a counting device with eight digits. The three left digits turn red and indicate the number of liters of water used. The remaining five digits are colored black. They indicate the amount of water used in cubes. When taking readings, it is necessary to look at the black numbers - the water consumption in cubes. In this case, red numbers should also be taken into account. Their accounting is necessary for rounding the result up or down.

How to read water meter readings - example

Let us explain what numbers need to be written off from the water meter using an example. Only installed counters will show 8 zeros, after a month the readings will increase and, for example, become 00012876. First you need to look at the first five black digits, in our example it is 00012 and then at the last 3 red digits - 876. These numbers mean what the month was spent 12 cubic meters and 876 liters. Only cubes need to be delivered to the water utility, so our liters should be rounded up to cubes. In our case, rounding will occur in the big direction. That is, when transmitting testimony, the number 13 will be indicated.

After another month has elapsed, the water meter will already show 00026113. These figures indicate that 26 cubic meters and 113 liters were used, rounding down in this case. Therefore, the result will be 26 cubes. Next, you need to subtract from this figure the amount of water already paid for last month. That is, we subtract 13 from 26 and it turns out that 13 cubic meters of water were used this month. It is necessary to make such a calculation monthly. Having analyzed this example, you will be able to independently solve the question "how to correctly take the readings of the water meter in the apartment."

When to take water meter readings

How to write off the readings of water meters is understandable. Now you need to deal with the question - when to take readings of water meters. According to the rules, Vodokanal needs to transfer data from meters until the 27th of every month. If the readings were not presented, then the water bill as the average value of the water consumption for the previous months.

How to fill in water meter readings

It is important not only to take readings correctly, but also to fill them in correctly. Only current data should be entered. If data is supplied from communal apartment, then only one account is indicated in the form. It will subsequently be divided by the number of people registered in the apartment.

How to write water meter readings? The form should be filled out correctly, clearly spell out the numbers and letters. If the document is filled out illegibly, or the entries go beyond the boundaries, then the completed form will be considered invalid. In this case, you will have to pay according to the average standards.

How to transfer water meter readings correctly

There are several ways to transmit water meter readings:

• by phone,
• bring with evidence to the housing authority,
• through the Internet.

How to transmit water meter readings by phone? To do this, call your housing authority. The telephone number of the authority is indicated on the receipt. When transferring testimony in this way, you should provide not only the data taken, but also your address and the name of the owner.

For transmission taken readings the second way is to bring the completed form to the housing authority and put it in a specially designated box. It is very important that the form is filled out clearly and correctly.

What numbers to enter the readings of the water meter through? When transmitting readings in this way, it is necessary to indicate the current readings of the meters. The difference is usually calculated automatically. If the numbers are too large, then cancel the action, check the correctness of the input and try again.

Plumbing verification

Long before reading water meters in the new month, it is recommended that you carefully check your existing plumbing for water leaks. Timely detection of leaks will avoid unnecessary costs.

The easiest way is to watch the counter. If the water meter wheel is in place, then all equipment is working properly. If water is not used anywhere, and the water meter continues to work, then this may indicate a plumbing malfunction.

Have you checked all the equipment and found no faults, but the meter readings are still in doubt? In this case, there is an easy way to check the operation of the counter. For the experiment, you only need a 20-liter pan. Before starting the test, remember the meter reading, then fill the pan five times. So you spend exactly 100 liters of water. Now it remains only to take readings from the counter. If the difference is more or less than 100, then you should contact the appropriate authority for a malfunction of the device.

So that in the house there is always cold and hot water, and the bills do not shock you, you must remember to transfer the consumption readings to the appropriate authorities every month. You should also regularly check all plumbing and water meter for serviceability. As a reminder, it is recommended to have a calendar where you mark the day of the reading every month.

In accordance with Decree of the Government of the Russian Federation of May 13, 2013 No. 406 “On state regulation of tariffs in the field of water supply and sanitation”, with a centralized hot water supply system in a closed system, a two-component tariff for hot water is set, consisting of “ cold water component "(rub. / m 3) and" component for thermal energy » (rub/Gcal). The resource supplying organization supplying hot water makes settlements with the utility service provider (management company, HOA) for 2 resources: cold water– according to the tariff for the “cold water component”; thermal energy– according to the tariff for the “thermal energy component”. The value of the component for cold water is calculated by the tariff regulator based on the tariff for cold water. The value of the component for thermal energy is determined by the tariff regulator in accordance with guidelines based on the following components: heat tariff; maintenance costs centralized systems hot water supply in the area from central heating points (inclusive), where cooking is carried out hot water, up to the point on the boundary of the operational responsibility of the subscriber and the regulated organization, if such costs are not included in the heat tariff; the cost of heat energy losses in pipelines in the section from the facilities where hot water is prepared, including from central heating points, including the maintenance of central heating points, to a point on the border of the operational responsibility of the subscriber and the regulated organization, if such losses are not taken into account when setting tariffs for thermal energy; costs associated with the transportation of hot water. Utility service providers 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 the Decree of the Government of the Russian Federation of May 6, 2011 No. 354 (hereinafter referred to as the Rules), calculate the amount of payment for the utility service for hot water supply for the volume of hot water consumed in cubic meters. In accordance with the Rules, the amount of payment (P i) for the utility service for hot water supply, in a room equipped with an individual device study that hot water is determined by the formula: P i \u003d V i n * T to p (1), where: V i n is the volume (quantity) consumed for billing period in i-th residential or non-residential premises communal resource, determined by the readings of an individual meter; T to p - the tariff for the utility resource. Since the tariff for the utility resource "hot water" is set in the form of two components, the utility service provider with hot water consumers calculates for the components: cold water and thermal energy for the needs of hot water supply. The amount of thermal energy (Gcal / m 3) for the needs of hot water supply per 1 m 3, as a rule, the contractor of public services is determined on the basis of common house (collective) readings of hot water meters and thermal energy in hot water. It should be noted that the utility service provider makes settlements with the resource supplying organization based on the readings of the same house-wide (collective) meters for hot water and thermal energy in hot water. The amount of thermal energy consumed in hot water in the i-room (Gcal) is determined by multiplying the amount hot water by individual device metering (m 3) for the specific consumption of thermal energy in hot water (Gcal / m 3). The volume of hot water determined by an individual meter (m 3) is multiplied by the tariff "component for cold water" (ruble / m 3) — this is the payment for cold water as part of hot water. The amount of heat energy in the consumed hot water (Gcal) is multiplied by the “component for heat energy” tariff (RUB/Gcal) — this is the payment for heat energy as part of hot water. In accordance with information letter of the Federal Tariff Service of Russia dated November 18, 2014 No. SZ-12713 / 5 “On the regulation of tariffs for hot water in a closed hot water supply system for 2015”, it is said that the authorities executive power subjects of the Russian Federation in the field of state regulation of prices (tariffs) entitled to decide on the establishment of tariffs for hot water in a closed hot water supply system per 1 cu. m. At the same time, the calculation of the tariff for hot water (T hot water) per 1 m 3 is carried out according to the formula: T hot water \u003d T cold water * (1 + K pv) + US central heating + T t / e * Q t / e (2), where : T hvs - tariff for cold energy (rubles / cubic meters); T t / e - tariff for thermal energy (rubles / Gcal); K pv - coefficient taking into account water losses in closed systems heat supply from central heating points to the connection point; unit costs for the maintenance of hot water supply systems from central heating points to the boundaries of the balance sheet of consumers (excluding losses) if such costs are not included in the tariffs for thermal energy (capacity), per 1 cubic meter. m; Q t / e - the amount of heat required to cook one cubic meter hot water (Gcal / m3). At the same time, the amount of heat for the preparation of one cubic meter of hot water (Q t / e) is determined by calculation, taking into account the heat capacity, pressure, temperature, water density, heat loss in risers and heated towel rails .Thus, the accrual in the receipt for hot water depends on the form in which the regulatory body sets the tariff for hot water: for two components (cold water and thermal energy) or per cubic meter. In question charges for 2 components (cold water and heat energy) are given, but the municipality and tariffs for the components are not indicated. If we assume that the consumption of hot water was 10 m 3, then the tariff for the “cold water component” is 331 rubles. / 10 m 3 \u003d 33.10 rubles / m 3. If we assume that the tariff for the “thermal energy” component is 1800 rubles / Gcal, the amount of consumed thermal energy is: 1100 rubles. / 1800 rubles / Gcal \u003d 0.611 Gcal, respectively, for heating 1 m 3 of hot water, the consumption of thermal energy was 0.611 Gcal / 10 m 3 \u003d 0.0611 Gcal / m 3. Chief Economist of Yurenergo Group of Companies Isaeva T.V.

With the advent of cold weather, many Russians are worried about the question of how to pay public utilities. For example, to how to calculate hot water and how often you should pay for these services. To answer all these questions, you first need to clarify whether a water meter is installed in this dwelling. If the counter is installed, then the calculation is made according to a certain scheme.

The first thing to do is to look at the receipt for utility services, which came last month. In this document, you should find a column that indicates the amount of water consumed over the past month, we need figures with indicators at the end of the last reporting period.

The first thing to do is to look at the receipt for utility services, which came last month

After these statements are written out, they should be entered in new document. In this case, we are talking about a receipt for payment of utility bills for the next reporting period. As you can see, the answers to the questions, how to calculate the cost of hot water by the meter, how to determine its consumption, are quite simple. It is necessary to timely and correctly take all the readings of the water meter.

By the way, many management companies themselves enter the above information into payment document. In this case, you do not have to look for data in old receipts. You also need to remember that in situations where the water meter has just been installed and these are the first readings, the previous ones will be zero.

The initial readings of some modern counters may not contain zeros, but some other numbers.

I would also like to clarify that the initial readings of some modern meters may not contain zeros, but some other numbers. In this case, in the receipt in the column where you need to indicate the previous readings, you need to leave these numbers.

The process of searching for previous meter readings is very important if you need to figure out how to calculate hot water from a meter. Without these data, it will not be possible to correctly calculate how many cubic meters of water were used in this reporting period.

So, before you start studying the question of how to calculate the cost of hot water, you should learn how to take readings from a water meter.

Designations on the counter

Almost all modern counters have a scale with a minimum of 8 digits. The first 5 of which are black, but the second 3 are red.

Important

It is important to understand that only the first 3 digits are displayed in the receipt, which are black. Because this is the data of cubic meters, and it is on them that the cost of water is calculated. But the data that is colored in red is liters. They do not need to be listed on invoices. Although these data make it possible to estimate how many liters of water a particular family consumes for a certain reporting period. Thus, you can understand whether it is worth saving on this benefit or whether the expense is within the normal range. And of course, you can determine how much water is spent on taking bath procedures, and how much on washing dishes, and so on.

It is important to understand that only the first 3 digits are displayed in the receipt, which are black

In order to correctly understand how to calculate the tariff for hot water, you should know on which day of the month the readings of this device are taken. Here, it must be remembered that water meter data must be taken at the end of each reporting period, after which they must be transferred to the appropriate authority. This can be done through phone call or over the Internet.

On a note! It should be remembered that the figures are always indicated at the beginning of the reporting period (that is, those that were removed last month) and at the end (these are those that are removed now).

This regulation is spelled out in the Decree of the Government of the Russian Federation of 05/06/2011, its number 354.

How to correctly calculate the service?

It is no secret that the legislation of our country is constantly changing, in connection with which citizens begin to worry about the question of how to calculate hot water or any other utility costs.

If we talk specifically about water, then we should take into account the fact that the payment consists of certain components:

• indicators of the water meter, which is located in the room and controls the flow of cold water;
• indicators of the meter, which shows the consumption of hot water in this apartment;
• indicators of the device, which calculates the consumption of cold water for all tenants;
• data of the meter that controls the consumption by the residents of the house, it is installed in the basement of the house;
• the share of a particular apartment in the total expenditure;
• share, which corresponds to a particular apartment in this house.

The penultimate indicator is the most incomprehensible, although in fact everything is quite accessible. It is taken into account when determining the amount of the resource that was spent on everyone. It is also called "common house needs." This, by the way, also applies to the last indicator, it is calculated when general house needs are calculated.

Calculation of hot water consumption

As for the first two indicators, they are quite understandable. They depend on the residents themselves, because a person himself can choose for himself whether to save the consumption of a particular resource or not. But in other cases, it all depends on how often wet cleaning at the entrance of the house, from the number of riser leaks, and so on.

The worst thing about this settlement system is that almost all of the common house needs are fictitious. Indeed, in every house there are tenants who incorrectly indicate their individual indicators, or, for example, one person is registered in their apartment, but five live. Then the general house needs should have been calculated based on the fact that 3 people live in apartment No. 5, and not 1. In this case, everyone else would have to pay a little less. As you can see, the question of how to calculate hot water still needs careful study.

That is why our officials are still trying to figure out how to calculate the payment for hot water and what mechanism would be the most successful.

Does everyone have the same rates?

To save money, you should always screw on the tap, if in this moment no need to use water

To do this, just go to the site of the management company or just call there. Also, such information is contained on the receipt, which comes to each tenant.

After these data are found, the cost of spent cubic meters of the resource should be calculated. Further, it is quite simple to calculate the payment for hot water, this is done in the same way as in the case of all other resources. You should take the number of cubic meters spent and multiply by a specific tariff.

It should be noted that today there are many ways to save hot water consumption, thereby reducing your costs of paying for it. To do this, you can use special nozzles on the faucet, they will help not to spray water so much and control the power of pressure. You should also open the faucet valve not at full strength, so the jet will go under less pressure, but the water will not scatter in all directions. And of course, you should always screw on the tap, if at the moment it is not necessary to use water. For example, when a person brushes his teeth or washes his hair (while the head is being soaped or the toothbrush is being smeared, the water tap can be closed).

All these tips will help reduce the cost of paying for hot or cold water, thereby helping to correctly calculate the consumption of hot water.

The difference between hot and cold water calculations

Of course, in this formula, as in the one that takes into account the consumption of hot water, there are many flaws. Due to the fact that general house indicators are taken into account, it is difficult to control where the difference between the individual indicators of all residents and the data that was taken from the water meter installed on the house went. Perhaps everything really is, and all this water went to clean the entrance. But this is hardly believable. Of course, there are residents who deceive the state and give incorrect data, but there are also errors in the operation of the pipeline system itself (sewer pipes in most houses are old and can leak, so the water goes nowhere).

Hot water invoice

For a long time our government has been thinking about how to correctly calculate hot and cold water and how to improve the existing mechanism.

For example, in 2013, our authorities came to the conclusion that it is necessary to establish standard norms for general house needs and take these data into account when calculating the cost of one cubic meter of water. This helped to somewhat restrain the zeal of our management companies and help the citizens of the country. You can find out these figures from the management company. But this applies only to those cases where the tenants have entered into an agreement with the management company. If we are talking about Vodokanal, then each settlement will have its own separate fixed minimum payment. And, let's say, an overpayment in this reporting period can cover expenses in the next one.

As you can see, there is a whole scheme that makes it clear how to calculate hot water heating or how to calculate how much to pay for cold water consumption.

Of course, installing meters on cold, and even more so, hot water, helps to save family budget. Therefore, the use of water meters is considered appropriate, especially since from 2016 tariffs for hot and cold water will be significantly increased. Now we ask ourselves the question: “How to count water according to the meters installed in your apartment?”

We purchased meters and installed them on pipes.

IMPORTANT! Be sure to inform the billing company, most likely your home owner, that you have the appliances, and also tell the operator the original readings contained on them.

To calculate the volume of water spent per month, indicate the initial figures that you reported on the receipt, and now we are going to take readings from the meters.

Water meters of the new generation have a scale of 8 digits, black numbers come first, and the last ones are red. The receipt indicates only the first 5 black numbers, which show the amount of resources spent.

It is best to take readings every month in the same period so that the amount of utility bills is approximately predictable. This can be immediately after receipt of the receipt or before payment of the receipt.

If you pay utility bills at the checkout, then write down on the receipt the numbers currently displayed on the devices and the numbers that were reported to the public utilities after the water meters were installed.

If you pay utility bills via the Internet, then these readings are driven into an electronic document.

If you pay utility bills after installing the meter for more than a month, at least the second, then in the column “previous readings” you write the numbers from the last receipt, which were displayed in the column “testimonies on the day of discharge”.

What regulatory documents determine the amount of payment for water?

Currently, when calculating water fees, utilities rely on Decree of the Government of the Russian Federation No. 354, which entered into force in the fall of 2012, and was adopted on May 06, 2011.

The new accounting standards and rules are more fair, but still need to be improved.

So, when calculating the payment for water by meters, take into account:
1. the amount of resource spent in a particular apartment, according to metering devices (we are talking about the volume of hot and cold water),
2. the amount of resource spent in the house as a whole, according to the metering device located in the basement of the house,
3. the size of the share of your apartment in the common property,

The value of the first component will depend only on how much water your family consumes per month.

The third component is a constant value that you cannot influence in any way.

But the size of the second component depends on the decency of your neighbors, who may not correctly indicate the readings on their counters. This also includes water overruns resulting from pipe leaks.

How to calculate the payment for water?

The figure that will be indicated on the receipt as payment for the spent water is determined by multiplying the volume of the resource spent by the tariff set in your city, town, village, and so on.

IMPORTANT! In order to find out the amount of the tariff, you can either call the company that manages your house, or independently find a legal document on the Internet or in the legal database (Garant, Consultant Plus). Take a closer look at the receipts, perhaps they also have the necessary information.

How to calculate wastewater costs?

For withdrawal waste water a fee is also provided, which is calculated according to the figure you specify, deducted from the counters. The cost of wastewater is calculated by multiplying the total volume of the resource spent by the tariff, the value of which you can also find out from the utilities.

IMPORTANT! Tariffs are updated annually in accordance with the legislative normative act of the authority local government. It is important to keep track of these changes.

How do you calculate the total consumption of cold water?

There is no point in specifying large and complex formulas. I just want to describe the quantities that are taken into account when calculating the general house consumption of the resource:
1. the total amount of cold water used by any owners of the premises of the house, according to common house water meters,
2. the total volume of hot water consumed by any owners of the premises of the house, according to common house water meters,
3. the total volume of water that is used to provide heating at home,
4. the area of ​​​​the premises of the whole house as a whole,
5. the area of ​​your apartment.

CONCLUSION! Thus, the overused water is determined in relation to the calculated norm for your apartment building.

The amount of overused resource, as already noted, is affected by:
1. water leakage through riser pipes,
2. the number of people who live in your home and use the resource, but are not registered at this address and therefore do not pay utility bills,
3. "insidious neighbors" who do not indicate the true amount of water spent.

The latest Rules, which are already referred to in the article, legislate that all overused water must be paid by the owners of any premises of the house, in proportion to the area they own. Like this!

How do you calculate the total consumption of hot water?

Similar to the previous situation, there is a long and incomprehensible formula that includes the same quantities that already affect hot water supply. All the same, we will not repeat ourselves.

Limits on collection of common house needs

Since 2013, a limit has been imposed on the amount of payment for general house expenses. The legislator, one might say, took pity on the citizens, who are already burdened enough with the costs associated with utility bills.

These limits are intended to curb the appetite of our home-running organizations. If you would like information on this matter, please write to your management company. You should definitely get an answer.

The Decree of the Government of the Russian Federation of April 16, 2013 established that the limits should not be exceeded when calculating a payment for general house consumption.

IMPORTANT! The limits set by the legislature can be changed by the decision of the owners of housing in your home. So watch out!
I ask you to say that your utilities cannot independently provide you with a resource amount exceeding fixed limits for payment.

But if there is a protocol of the meeting, where the tenants and other owners of the premises agree with other values, this rule is no longer valid.

If you are not a homeowner in apartment building, and you pay utility bills using a private house, payment for water is calculated in the same way, only taking into account other tariffs, which can be found out by correspondence with your public utilities.

The calculation of hot water supply systems consists in determining the diameters of the supply and circulation pipelines, selecting water heaters (heat exchangers), generators and heat accumulators (if necessary), determining the required pressure at the inlet, selecting booster and circulation pumps if they are needed.

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, 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 group of consumers: 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 the total number of 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.

Coolant parameters in the winter settlement period, when they work heating networks buildings, 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 = 5 ºC and t c = 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;

W total - total area the living 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.