Hot water supply
5.1. Estimated costs in the hot water supply network. 5.1.1. The maximum second water flow and the probability of operation of sanitary appliances are determined similarly to cold water supply (clauses 3.1.1, 3.1.2): a) for residential buildings in the hot water supply network: for one house:
(From the total number of devices in the calculation of hot water supply, watering taps and flush tanks are subtracted.) b) for a public building in the hot water supply network:
c) on section 12-13, supplying hot water to two residential buildings and a public building:
d) on section 13-14, supplying hot water to four residential buildings and a public building:
5.1.2. Secondary consumption q0 by various devices serving different water consumers (see clause 3.1.3): a) in an area supplying hot water to two residential buildings and a public building:
b) on a site supplying hot water to four residential buildings and a public building:
5.1.3. The maximum hourly water consumption and hourly probability are determined similarly to cold water supply (see clauses 3.1.4, 3.1.5): a) for a residential building:
b) for a public building:
c) for a microdistrict:
5.1.4. Hourly water consumption by a sanitary fixture with different consumers in the microdistrict (see clause 3.1.6):
5.1.5. Maximum hourly water consumption:
a) for a public building:
b) for a microdistrict:
The water heater is calculated based on the maximum hourly flow rate. 5.1.6. Average hourly water consumption per day of maximum water consumption (see clause 3.1.8): a) for one house:
b) for a microdistrict:
c) for an apartment:
5.2. Hydraulic calculation of the hot water supply network in water intake mode. Hydraulic calculation of hot water supply systems is carried out for the calculated hot water flow rate, taking into account the circulation flow rate, determined by formula 14, [2]:
where: kcir is the coefficient accepted: for water heaters and the initial sections of systems up to the first water riser according to Appendix 5, [2]; for the remaining sections of the network - 0. (First, the hydraulic calculation is made for the design flow rate - qh , then after determining the circulation flow rate (clause 5.3.1), adjustments are made to the initial sections of the network.) Due to the fact that the design flow rate for water collection is - qh=6.13 l/s (Table 4, section 14-15), circulation flow - qcir=1.21 l/s (Table 5, section 14-B), ratio qh/qcir=6.13/1 ,21=5.07 > 2.1 , circulation is not taken into account when calculating the system in water withdrawal mode. Pressure losses in pipeline sections are determined taking into account the overgrowth of pipes according to formula 16, [2]:
where: i - specific pressure loss, accepted in accordance with Appendix 6, [2]; kl is a coefficient that takes into account pressure losses in local resistances, the values of which are taken in accordance with clause 8.3, [2]; The network calculation is carried out in the form of Table 4. (The length of the network sections on the water risers is increased by 3 m due to the connection of heated towel rails.) 5.3. Hydraulic calculation of supply and circulation networks of hot water supply in circulation mode. 5.3.1. Determination of heat loss in the hot water supply network and circulation flow rates. The amount of heat loss (kW) is determined by formula 13.5, [7]:
where: li is the estimated length of the section, m;
— specific heat loss at the site (W/m)
Table 4
Hydraulic calculation of hot water supply network
taken equal to k=11.63 W/(m².deg); dн is the outer diameter of the pipe in the design section, m, taken according to the data in Table 1, [4]; h - thermal insulation efficiency coefficient, h = 0.6 ; Dtm is the difference between the average temperature of hot water in the calculated area tg.v and the ambient air temperature tb :
The ambient air temperature tb is assumed to be: in living quarters and bathrooms – 20 Cº; in basements – 5 Cº; in the channel - 40 Cº; on design sections with different laying conditions (between buildings, when part of a section with a total length li is laid in a channel - lk, and part of a section with a length lп - in the basement):
Average hot water temperature in the calculated areas:
Where:
— hot water temperature at the beginning of the calculation section (for the first calculation point, 50 Cº is assumed (clause 2.2, [2]));
hot water temperature at the end of the calculated section:
where: δt is the temperature difference per linear meter:
where: ∆t is the temperature difference in the supply pipelines of the system from the water heater (60 Cº) to the most distant water point (50 Cº), assumed to be 10 Cº, clause 8.2, [2];
-total length of pipelines from the water heater to the dictating water point, m (Table 5).
The temperature of hot water at the beginning of the next section is assumed to be equal to the temperature of hot water at the end of the calculated section. The circulation flow of hot water is determined by formula 15, [2]:
where: β is the circulation misadjustment coefficient for systems that provide for water circulation through water risers with variable resistance of the circulation risers, β=1 . Heat loss in a public building (kW) is determined approximately by the formula:
where: K-coefficient, taking into account heat loss by pipelines, is taken K=0.05 ;
-cm. clause 5.1.5;
tc - cold water temperature, tc = +5 C º ; The calculation is performed in the form of table 5. 5.3.2. Hydraulic calculation of the hot water supply network in circulation mode. When hydraulically calculating the supply network in circulation mode, specific pressure losses are determined for circulation flow rates when they pass through the hot water supply network calculated in Table 4, taking into account the overgrowth of pipes, in accordance with recommended Appendix 6, [2]. The calculation is performed in the form of table 6. 5.3.3. Hydraulic calculation of the hot water supply circulation network. The selection of the diameters of the circulation network must be made taking into account the correlation of pressures and pressure losses in various branches of the hot water supply system (clauses 8.5-8.7, [2]). In this project, pressure and head loss in individual branches are not linked.
Table 5
Calculation of heat loss and circulation flow rates in the hot water supply network
Table 6
Hydraulic calculation of the hot water supply network in circulation mode
Table 7
Hydraulic calculation of the hot water supply circulation network
In hydraulic calculations, the diameters of the circulation network are taken to be 1-2 sizes smaller than the diameters of the corresponding sections of the supply network, the diameter of the ring jumper is not less than the diameter of the supply riser. The calculation is performed in the form of Table 7.
Calculation of the cost of heating and hot water services
2017
Calculation of the cost of thermal energy for heating 1 sq.
meters of total area in 2021: Heating consumption standard * Thermal energy tariff = cost of thermal energy for heating 1 sq. m:
January-April 0.0366 Gcal/sq. m * 1197.50 rub/Gcal = 43.8285 rub/sq.m.
May 0.0122 Gcal/sq. m * 1197.50 rub./Gcal = 14.6095 rub./sq.m
October 0.0322 * 1211.33 rubles/Gcal = 39.0048 rubles/sq.m.
November-December 0.0366 Gcal/sq. m * 1211.33 rub./Gcal = 44.3347 rub./sq.m
Calculation of the cost of service for hot water supply per person in 2021:
DHW consumption standard * Heat energy tariff = cost of DHW service per 1 person
An example of calculating the cost of a hot water supply service for 1 person with a fully equipped apartment (from 1 to 10 storeys, equipped with a sink, washbasin, bathtub 1500-1700 mm long with shower) in the absence of hot water meters:
January-June 0.2120 Gcal/per person. per month *1197.50 rub./Gcal = 253.87 rub./person.
July-December 0.2120 Gcal/per person. per month *1211.33 rub./Gcal = 256.80 rub./person.
Calculation of the cost of service for hot water supply using a domestic hot water meter in 2021:
The standard thermal energy consumption for heating is 1 cubic meter. m of water * Tariff for thermal energy = cost of service for heating 1 cubic meter. m
January – June 0.0467 Gcal/cub. m * 1197.50 rub./Gcal = 55.9233 rub./cubic. m.
July-December 0.0467 Gcal/cu.m. m * 1211.33 rub./Gcal = 56.5691 rub./cubic. m
2016
Calculation of the cost of thermal energy for heating 1 sq. meters of total area in 2021:
Heating consumption standard * Thermal energy tariff = cost of thermal energy for heating 1 sq. m:
January-April 0.0366 Gcal/sq. m * 1170.57 rub/Gcal = 42.8429 rub/sq.m.
May 0.0122 Gcal/sq. m * 1170.57 rub./Gcal = 14.2810 rub./sq.m
October 0.0322 * 1197.50 rubles/Gcal = 38.5595 rubles/sq.m.
November-December 0.0366 Gcal/sq. m * 1197.50 rub./Gcal = 43.8285 rub./sq.m
Calculation of the cost of service for hot water supply per person in 2021:
DHW consumption standard * Heat energy tariff = cost of DHW service per 1 person
An example of calculating the cost of a hot water supply service for 1 person with a fully equipped apartment (from 1 to 10 storeys, equipped with a sink, washbasin, bathtub 1500-1700 mm long with shower) in the absence of hot water meters:
January-June 0.2120 Gcal/per person. per month *1170.57 rub./Gcal = 248.16 rub./person.
July-December 0.2120 Gcal/per person. per month *1197.50 rub./Gcal = 253.87 rub./person.
Calculation of the cost of service for hot water supply using a domestic hot water meter in 2021:
The standard thermal energy consumption for heating is 1 cubic meter. m of water * Tariff for thermal energy = cost of service for heating 1 cubic meter. m
January – June 0.0467 Gcal/cub. m * 1170.57 rub./Gcal = 54.6656 rub./cubic. m
July-December 0.0467 Gcal/cu.m. m * 1197.50 rub./Gcal = 55.9233 rub./cubic. m
2015
Calculation of the cost of thermal energy for heating 1 sq. meters of total area in 2015:
Heating consumption standard * Thermal energy tariff = cost of thermal energy for heating 1 sq. m:
January-April 0.0366 Gcal/sq. m * 990.50 rub./Gcal = 36.2523 rub./sq.m
May 0.0122 Gcal/sq. m * 990.50 rub./Gcal = 12.0841 rub./sq.m
October 0.0322 * 1170.57 rubles/Gcal = 37.6924 rubles/sq.m.
November-December 0.0366 Gcal/sq. m * 1170.57 rub./Gcal = 42.8429 rub./sq.m
Calculation of the cost of hot water supply services per person in 2015:
DHW consumption standard * Heat energy tariff = cost of DHW service per 1 person
An example of calculating the cost of a hot water supply service for 1 person with a fully equipped apartment (from 1 to 10 storeys, equipped with a sink, washbasin, bathtub 1500-1700 mm long with shower) in the absence of hot water meters:
January-June 0.2120 Gcal/per person. per month *990.50 rub./Gcal = 209.986 rub./person.
July-December 0.2120 Gcal/per person. per month *1170.57 rub./Gcal = 248.1608 rub./person.
Calculation of the cost of service for hot water supply using a domestic hot water meter in 2015:
The standard thermal energy consumption for heating is 1 cubic meter.
m of water * Tariff for thermal energy = cost of service for heating 1 cubic meter. m
January – June 0.0467 Gcal/cub. m * 990.50 rub./Gcal = 46.2564 rub./cubic. m
July-December 0.0467 Gcal/cu.m. m * 1170.57 rub./Gcal = 54.6656 rub./cubic. m
year 2014
Calculation of the cost of thermal energy for heating 1 sq. meters of total area in 2014:
Heating consumption standard * Thermal energy tariff = cost of thermal energy for heating 1 sq. m:
January-April 0.0366 Gcal/sq. m * 934.43 rub./Gcal = 34.2001 rub./sq.m
May 0.0122 Gcal/sq. m * 934.43 rub./Gcal = 11.4000 rub./sq.m
October 0.0322 Gcal/sq. m * 990.50 rub./Gcal = 31.8941 rub./sq. m
November – December 0.0366 Gcal/sq. m * 990.50 rub./Gcal = 36.2523 rub./sq.m
Calculation of the cost of service for hot water supply per 1 person in 2014:
DHW consumption standard * Heat energy tariff = cost of DHW service per 1 person
An example of calculating the cost of a hot water supply service for 1 person with a fully equipped apartment (from 1 to 10 storeys, equipped with a sink, washbasin, bathtub 1500-1700 mm long with shower) in the absence of hot water meters:
January-June 0.2120 Gcal/per person. per month * 934.43 rub./Gcal = 198.0991 rub./person.
July – December 0.2120 Gcal/per person. per month * 990.50 rub./Gcal = 209.986 rub./person.
Calculation of the cost of service for hot water supply using a domestic hot water meter in 2014:
The standard thermal energy consumption for heating is 1 cubic meter. m of water * Tariff for thermal energy = cost of service for heating 1 cubic meter. m
January – June 0.0467 Gcal/cub. m * 934.43 rub./Gcal = 43.6378 rub./cubic. m
July – December 0.0467 Gcal/cubic. m * 990.50 rub./Gcal = 46.2564 rub./cubic. m
year 2013
Calculation of the cost of thermal energy for heating 1 sq. meters of total area in 2013:
Heating consumption standard * Thermal energy tariff (supplier MUP "ChKTS" or Mechel-Energo LLC) = The cost of thermal energy for heating 1 sq. m
- January-April 0.0366 Gcal/sq. m * 851.03 rub./Gcal = 31.1477 rub./sq.m
- May 0.0122 Gcal/sq. m *851.03 rub./Gcal =10.3826 rub./sq.m
- October 0.0322 Gcal/sq. m * 934.43 rub./Gcal = 30.0886 rub./sq. m
- November – December 0.0366 Gcal/sq. m * 934.43 rub./Gcal = 34.2001 rub./sq.m
Calculation of the cost of service for hot water supply per 1 person in 2013:
DHW consumption standard * Heat energy tariff (supplier MUP "ChKTS" or Mechel-Energo LLC) = cost of DHW service per 1 person
An example of calculating the cost of a hot water supply service for 1 person with a fully equipped apartment (from 1 to 10 storeys, equipped with a sink, washbasin, bathtub 1500-1700 mm long with shower) in the absence of hot water meters:
- January-June 0.2120 Gcal/per person. per month * 851.03 rub./Gcal = 180.4184 rub./person.
- July – December 0.2120 Gcal/per person. per month * 934.43 rub./Gcal = 198.0991 rub./person.
Calculation of the cost of service for hot water supply using a domestic hot water meter in 2013:
The standard thermal energy consumption for heating is 1 cubic meter. m of water * Tariff for thermal energy (supplier MUP "ChKTS" or LLC "Mechel-Energo") = cost of service for heating 1 cubic. m
- January – June 0.0467 Gcal/cub.
Consumption
It can be approximately estimated by consumption rates for individual plumbing fixtures. If desired, it is easy to find the data in one of the annexes to SNiP 2.04.01-85; For the convenience of the reader, we present an excerpt from it.
| Device type | Cold water consumption, l/s | Total consumption of hot and cold water, l/s |
| Irrigation tap | 0,3 | 0,3 |
| Toilet with tap | 1,4 | 1,4 |
| Toilet with cistern | 0,10 | 0,10 |
| Shower stall | 0,08 | 0,12 |
| Bath | 0,17 | 0,25 |
| Washing | 0,08 | 0,12 |
| Wash basin | 0,08 | 0,12 |
In apartment buildings, when calculating consumption, the probability coefficient of simultaneous use of devices is used. It is enough for us to simply sum up the water consumption through devices that can be used simultaneously. Let's say a sink, shower and toilet will give a total flow rate of 0.12 + 0.12 + 0.10 = 0.34 l/s.
Water consumption through devices that can operate simultaneously is summed up.
