Apartment heating instructions for use. Apartment heating system - characteristic. Direct space heating with electrical appliances
Heating of an autonomous type is a heating system that is able to heat each room or the entire house. The most popular apartment heating in is individual.
The reason for this is the relatively low price and the presence of environmental safety. Although there is a place in the apartment.
Apartment heating system
- apartment heating apartment building allows residents to reduce the cost of tariffs for the types of services that are provided. In addition to the fact that there is an opportunity to save their finances, each of the tenants can, at any time, reach the one he needs when heating his apartment. by the most the best option installations required level temperature is just adjustment apartment buildings.
- Individual heating in residential premises from developers during the commissioning of the object makes it possible to slightly reduce the cost of one square meter. This is a result of the fact that builders have much more costs for laying communication systems. Besides, heating system in apartments of apartment buildings helps developers to develop many new territories that are far from settlements.
- Gas heating of apartment buildings significantly saves the natural gas with which it works. Compared to apartments gas heating using natural gas is more economical.
- Thanks to the autonomous heating system of apartments, the heat costs that are needed on the road from the source to the consumer are significantly reduced. becomes unnecessary additional insulation heating mains when supplying hot water in apartments to consumers, while the balancing process is quite quick and simple.
Comparative table of economic indicators
Additional insulation
Residents who rarely appear in their apartment, the best option will insulate the external walls, this will make it possible to retain heat for a longer period of time and minimize damage to structures due to moisture.
Particular attention should be paid to the ventilation system. During the adjustment of heating and, in particular, equipment operating with the help of gas, it must be understood that the result of decomposition must be output qualitatively. New buildings are thought out in such a way that they have everything you need. They are equipped with modern ventilation and cleaning systems. For example, washing heating system will happen quite easily, because its design is thought out precisely with such a bias.
Ventilation device
To install apartment heating in an apartment building, everything must be coordinated with certain authorities, while at the same time providing a project for the placement of equipment.
Boiler selection
When the choice comes to a boiler that needs to be installed in an autonomous heating system, then, depending on the type of wiring, it is worth giving preference to boilers with an isolated combustion chamber. This one consists of ventilation system, with which you can adjust the air supply levels yourself.
Very practical when characterized by cyclic work rhythms, which can provide a gentle method of getting rid of the combustion products that enter the air. The level of carbohydrate oxide that is excreted must be within the acceptable range.
That is, the positives apartment building quite pronounced. Installation various devices will make it possible to be independent of the work and speed of reaction of the housing and communal services company.
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Apartment heating or individual heating of apartments in multi-storey buildings last years is gaining great popularity. Developers and residents are attracted by the opportunity to create an individual and independent microclimate in their apartment.
Specially for individual heating apartments, German engineers from Vaillant developed a boiler. This is a quiet, reliable and, importantly, inexpensive and economical boiler.
Consider the option of creating heating on an example real home in Kostroma (Russia) with gas boilers installed in it
ADVANTAGES OF APARTMENT HEATING
Apartment heating gives residents freedom and independence in creating the microclimate of their own home. The situation known to all residents of multi-storey buildings, autumn, it is already cold outside, and heating will be turned on only after a week. In apartments with individual heating systems, this simply cannot be. In an apartment with a separate gas boiler heating season starts when the owners themselves simply press the button to turn on the boiler. Temperature control in each room is also in the hands of residents. You can raise the heating temperature when it gets colder and lower it when it's warm outside.
Another important advantage of apartment heating is the possibility of saving money when paying for heating and hot water supply. If the apartment is connected to the central heating system, the tenants are forced to pay not only for the heat they consume, but also for its losses through the main pipes, for the maintenance and repair of the common boiler house and heating mains, the work of the boiler house employees, the gas surcharge for boiler houses.
Apartment heating also simplifies the calculation of heat consumption. When using such a scheme, it is not necessary to install an individual heat and hot water meter for each apartment. In fact, only accounting for the consumption of gas, cold water and electricity is required. As a result, residents are confident that they pay only for those resources that are spent on their personal needs, and it is convenient for them to make calculations.
It is also beneficial for developers to support the development of apartment heating. Firstly, in such houses there is no need to lay heating mains and hot water systems. Secondly, installation engineering systems with this type of heating takes less time, which reduces construction costs.
INITIAL DATA
The object under consideration is a three-story apartment building from silicate brick located at st. Tereshkova, 48a in Kostroma. The house has 12 apartments - one-, two- and three-room apartments ranging from 43 to 86 m2 and with a ceiling height of 2.8 m. The building is connected to the power supply line, gas line, cold water supply line, and sewerage. The house is a new building, from the very beginning it was planned to use apartment heating in it, which was implemented. The installation of individual boilers made it possible to do without connecting the building to the DHW main and the heating main, since the heat carrier and water for DHW are heated directly in the apartments themselves. 
To provide apartment building systems with heat, compact wall-mounted gas boilers, including all the components necessary for the functioning of the heating and water supply system. Unlike large private houses, the apartment does not require the generation of large thermal power, therefore, in the building under consideration, medium-power boilers from the model range - 24 kW are installed per apartment. Such performance is more than enough to cover all the needs for heating and hot water supply of the apartment. In total, 12 boilers were installed in the building - one in each apartment.
Separately, it is worth talking about the Lynx models. In the market of boiler equipment, they have been known for a long time. First, the Lynx with a bithermic heat exchanger was introduced in the Protherm line. Then, in 2010, it was replaced by a new "Lynx" - a modern double-circuit gas wall-mounted boiler with separate heat exchangers. The model is unpretentious in operation and easy to maintain. The Protherm brand belongs to the large German concern Vaillant Group. The equipment of trademarks belonging to the Vaillant group has been widely used in Russia for a long time. A developed network has been created to support it. service centers, so components for boilers "Lynx" are easy to find in the regions of the Russian Federation.
A gas wall mounted boiler is installed in the kitchen. From above, pipes of an air duct equipped with thermal insulation and a chimney are connected to the boiler. The chimney is led into a separate channel leading to the roof. From below, a gas pipe is connected to the boiler (in the center), pipes of the water supply circuit (to the right and left of the gas supply) and a heating system (extreme pipes to the right and left)
The boiler is controlled from a small panel with two handles, which is located at the bottom of the body. The panel is equipped with an LCD display, which simplifies the process of setting the parameters of the boiler. Aluminum radiators are installed in the heated rooms. They are connected in a bottom-down pattern, chosen for this project for aesthetic reasons. On the roof of the house there is a brick channel 1.8 m high. Chimneys of boilers installed in the apartments are laid in it.
Heating system with boiler Protherm Lynx.
The apartments have a simple scheme for organizing heating and water supply, time-tested since the era of distribution geysers in domestic residential buildings. According to this diagram, the boiler is installed in the kitchen. A gas pipeline passes here, from which gas comes to power the stove and boiler. The boiler is connected to three different networks - a cold water supply system, a gas pipeline and an electrical network.
"Lynx" NK 24 is a model with low power consumption, it consumes 98 watts. To protect the device from power surges, it is powered through a voltage stabilizer. Water entering the boiler does not undergo any special treatment or purification, with the exception of primary mechanical cleaning mesh filter.
In the primary circuit of the boiler, water is heated for the heating system. The system is closed, two-pipe, that is, the coolant is supplied to the heating devices from one distributing pipe, and the cooled coolant enters the collecting pipe. The system is assembled from reinforced polypropylene pipes PN 25, resistant to high temperatures. Sectional aluminum radiators were chosen as heating devices. Since apartment heating allows you to set the desired coolant temperature for a given apartment, the radiators are connected without thermostatic fittings. Since the operating rules aluminum radiators they are prescribed to bleed the gases accumulating in them for at least the first year after installation, each appliance is provided with a manual air vent. The devices are connected according to the "bottom-down" scheme.
In its current version, the heating system regulates the power depending on the temperature of the coolant. Nevertheless, the Rys NK 24 heat generators provide for the possibility of installing optional room thermostats with air temperature sensors. In this case, the boiler will be able to maintain a comfortable climate, based on the data on the temperature in the room itself. This will allow it to work even more efficiently and reduce fuel costs. The manufacturer estimates that using room thermostats can save 15-25% energy compared to systems without thermostats. And if we take into account that the energy efficiency of apartment heating is already high, in total, when using an individual boiler with a thermostat, savings in comparison with energy costs for residents of houses with central heating can reach 70%. Therefore, the owners of apartments in this building will have the opportunity not only to use the already installed good equipment, but also to improve its functions, making it even more economical.
Each apartment has two tapping points: one in the kitchen to provide hot and cold water mixer at the sink, the second - in the bathroom, for shower and mixing equipment. The cold water supply pipeline is made of PN 20 polypropylene pipes, the DHW pipeline is made of PN 25 polypropylene pipes. Water for the DHW system is prepared in the secondary circuit of the boiler. Here, cold water entering the apartment from the main water supply enters the stainless steel plate heat exchanger. This is the so-called fast heat exchanger, which allows you to heat the water flowing through it in real time and not use storage tanks. Boiler performance (about 10.7 l/min) is sufficient to ensure hot water both kitchen and bathroom. The DHW support function is a priority for the boiler. This means that when the water in the mixers is turned on, the boiler directs all the power to the preparation of hot water for domestic needs, but when the mixers are closed, it operates in the mode of heating the heat carrier of the heating system.
According to building codes The house has a ventilation system. It solves the problem of supplying fresh air and removing exhaust air from the premises, but its work is not related to the operation of boilers. Each boiler in the house has its own autonomous air intake system from the street - through an air duct leading through the wall in the kitchen. It is made of stainless steel round tube with a diameter of 80 mm. From the outside, the air intake is closed with a protective grill that protects the channel from accidental entry of birds, animals, large objects, etc. A stainless steel pipe is also used to remove combustion products. From each heat generator, a separate chimney is laid on the roof, not connected to other chimneys. Therefore, the efficiency of gas removal from the boiler is not affected by the simultaneous operation of other boilers in the building. Chimneys are laid inside a brick channel that rises 1.8 m above the house.
Boilers in apartments will require periodic Maintenance. It is recommended once a year, before the start of the heating season, to inspect, clean the boilers, check the gas pressure on the burners, etc. After installation, the boiler will be assigned to the installation company for two years. After this period, the residents of the apartments have the right to either extend the contract with this organization, or transfer the care of the boiler to another company.
Today for consumers utilities due to the increase in their cost, apartment heating in an apartment building is becoming more and more relevant. Such heat supply differs from centralized and saves money. In the field of providing heat to residents of multi-storey buildings, certain standards and regulations apply. At the same time, experts note that centralized and apartment heating methods have their own nuances, advantages and disadvantages. The centralized system for supplying coolant and hot water is considered to be predominant, but it has serious disadvantages:
- a specific consumer of a thermal resource (an apartment owner) is not interested in its economical use and does not have the technical capabilities for this;
- transportation of the coolant from the heat source to the final consumer is carried out over long distances and at this stage large heat losses occur.
- there is no need to build expensive heating mains;
- the coolant from the place of production to the consumer is delivered without energy loss;
- each apartment owner has the opportunity to use the amount of heat he needs.
Arrangement of apartment heating system
The apartment heating system consists of:- heat generator, it is also a source of heat supply;
- hot water supply pipelines with water fittings;
- heating pipelines together with heating appliances.
A heat generator room is a public space or a separate room in an apartment for placing a heat generator and other equipment.
The system of apartment heating allows at the national level to save money that needs to be raised for the construction and repair of heating mains. At the same time, each owner of the heating boiler has the opportunity to personally regulate the heat in his apartment without paying fixed prices charged monthly at centralized system. It is clear that the owner of the living space in warm weather will not turn on the heating.
Besides central heating, which is becoming more expensive from year to year, does not always provide a comfortable temperature in the apartment in cold weather. There may be several reasons for this: an accident on an old worn-out heating main or the heating season, the regional administration decided to start later.
When there is an apartment heating system, in order to set the required temperature for different times of the day, a programmer is used that is connected to modern heating boilers. For example, if the owner
from morning to evening is at work, and there will be no other family members at home, then there is no need to maintain a high temperature in the apartment. The boiler will automatically provide the temperature set at, for example, 18 degrees.
Combined heating system, detailed video:
If we consider existing species heating in an apartment, it should be noted that individual apartment heating is a material incentive aimed at saving heat. For many years, consumers have been told that it is necessary to insulate apartments and windows, and not heat the street. But the exhortations of public utilities remain ineffectual. Now, if available, the amount of payments for gas depends on the degree of insulation of the apartment. Thus, for the owner of living space, a reduction in utility bills becomes a material incentive.
If you have your own double-circuit boiler, usually used when apartment-by-apartment horizontal heating is created in an apartment, residents are provided with both heating and hot water (read also: ""). As a result, when switching to an individual heat supply system, consumers are not threatened with hot water shutdown in the summer, which is so familiar to many residents of large cities.
Description:
In buildings with increased thermal protection of enclosing structures, apartment heating systems (with automatic thermostats for heating appliances and heat consumption meters both at the entrance to the building and for each apartment) create additional features and incentives for more efficient use of thermal energy.
Apartment heating system
Two-pipe horizontal heating system
Heating systems
In buildings with a height of two or more floors, for supplying coolant to apartments, two-pipe systems should be designed with lower or upper wiring of main pipelines, main vertical risers serving part of the building or one section.
The supply and return main vertical risers for each part of the section building are laid in special shafts of common corridors, stair halls.
In the shafts on each floor, built-in installation cabinets should be provided, in which floor-by-floor distribution manifolds with outlet pipelines for each apartment, shut-off valves, filters, balancing valves, and heat meters should be placed.
Apartment heating systems can be performed according to the following schemes:
Two-pipe horizontal (dead-end or associated) with parallel connection of heating devices (Fig. 1). Pipes are laid near the outer walls, in the floor structure or in special skirting boxes;
Two-pipe beam with individual connection by pipelines (loops) of each heater to the distribution manifold of the apartment (Fig. 2). It is allowed to connect "on the hitch" of two heaters within the same room. Pipelines are laid in the form of loops in the floor structure or along the walls under skirting boards. The system is convenient for installation, since pipelines of the same diameter are used, there are no pipe connections in the floor;
Single-pipe horizontal with closing sections and serial connection of heating devices (Fig. 3). The consumption of pipes is significantly reduced, but the heating surface of heating devices is increased by approximately 20% or more. The circuit is recommended for use with higher coolant parameters and a smaller temperature difference (for example, 90–70°C). By increasing the amount of water flowing into the device, the heating surface of the device decreases. The calculated temperature of the water leaving the last appliance must not be lower than 40°C;
Floor-standing with laying heating coils from pipes in the floor structure. Floor systems have a greater inertia than systems with heating devices, are less accessible for repair and dismantling. Possible options pipe laying schemes in systems floor heating shown in fig. 4, 5. Scheme according to fig. 4 ensures easy installation of pipes and uniform temperature distribution over the floor surface. The scheme according to fig. 5 provides approximately equal average temperature on the floor surface.
Bathroom heated towel rails are connected to the hot water supply system - when the building is supplied from heating networks or from an autonomous source, or to the heating system - with an individual heat source.
Should buildings with apartment heating be provided with heating of staircases, elevator lobbies?
In residential buildings with more than three floors, with a central or general autonomous source of heat supply, it is necessary to design the heating of stairwells, stairwells and elevator lobbies. In buildings with more than three floors, but not more than 10, as well as in buildings of any number of floors with individual heat sources, it is allowed not to design the heating of smoke-free staircases of the first type. At the same time, the resistance to heat transfer internal walls, enclosing an unheated staircase from residential premises, is taken equal to the heat transfer resistance of the outer walls.
Hydraulic calculations of apartment heating systems are carried out according to existing methods, taking into account recommendations for the use and selection of heating devices, developed on the basis of the results of the Research Institute of Sanitary Engineering when testing and certifying heating devices from various manufacturers.
The connection of the heater to pipelines can be carried out according to the following schemes:
Lateral one-way connection;
Radiator connection from below;
Lateral double-sided (versatile) connection to the lower radiator plugs. Versatile connection of pipelines should be provided for radiators with a length of not more than 2,000 mm, as well as for radiators connected “on a hitch”. In a two-pipe heating system, it is allowed to connect two heaters “on a hitch” within the same room.
Heating appliances, fittings, pipelines
In apartment heating systems, as in traditional heating systems, heaters, valves, fittings, pipes and other materials approved for use in construction and having certificates of conformity of the Russian Federation should be used.
In multi-apartment residential buildings, the service life of heating devices and pipelines of heating systems must be at least 25 years; in single-family houses, the service life is taken at the request of the customer.
As heating devices, it is advisable to use steel radiators or other devices with a smooth surface that cleans the surface from dust. It is allowed to use convectors with air control valves.
To regulate the heat flow in the premises, control valves should be installed near the heating devices. As a rule, automatic temperature controllers (with built-in or remote thermostatic elements) are installed in rooms with permanent residence of people, which ensure the maintenance of the set temperature in each room and save heat supply through the use of internal heat surpluses (domestic heat emissions, solar radiation).
For hydraulic balancing of individual branches of the apartment two-pipe heating system, valves with pre-setting are installed for all heating devices in the apartment.
For the hydraulic stability of the heating system of the building, it is planned to install balancing valves on the main vertical risers for each part of the building, section, and also at each floor distribution manifold.
In buildings with apartment heating systems, the following should be provided:
Installation in the ITP of a closed expansion tank and a filter for the building system with heat supply from heat networks and an autonomous heat source;
Installation of a closed expansion tank and a filter for each apartment with heat supply from an individual heat source.
When open expansion tanks the water in the system is saturated with air, which significantly activates the process of corrosion of the metal elements of the system, air locks are formed in the system.
The pipelines of the apartment heating system can be made of steel, copper, heat-resistant polymer or metal polymer pipes. In heating systems with pipelines made of polymer or metal-polymer pipes, the parameters of the coolant (temperature and pressure) should not exceed the maximum allowable values specified in the technical documentation for their manufacture. When choosing the parameters of the coolant, it should be taken into account that the strength of polymer and metal-polymer pipes depends on the operating temperature and pressure of the coolant. With a decrease in the temperature and pressure of the coolant below the maximum allowable values, the safety factor and, accordingly, the service life of the pipes increase. Pipelines of apartment heating systems, as a rule, are laid hidden: in strobes, in the floor structure. Open laying of metal pipelines is allowed. In the case of hidden laying of pipelines at the locations of collapsible connections and fittings, hatches or removable shields should be provided for inspection and repair.
When calculating heating devices in each room, at least 90% of the incoming heat from pipelines passing through the room should be taken into account. Heat losses due to cooling of the coolant in uninsulated openly laid horizontal pipelines are taken according to reference data. The heat flow of openly laid pipes is taken into account within:
90% with horizontal pipe laying near the floor;
70–80% when laying horizontal pipes under the ceiling;
85–90% for vertical pipe laying.
Thermal insulation is provided for pipelines laid in the grooves of external walls, in mines and in unheated premises, in floor areas with close placement of four or more pipes in the floor, ensuring an acceptable temperature on the surface.
Accounting for heat energy consumption
Apartment heating systems, on the one hand, provide the most comfortable living conditions that satisfy the consumer, and on the other hand, they allow you to regulate the heat output of heating devices in the apartment, taking into account the mode of residence of the family in the apartment, the need to reduce the cost of paying for heating, etc.
In a building with apartment heating systems, it is planned to account for the heat consumption of the building as a whole, as well as separately for each apartment and public and technical premises located in this building.
To account for the heat consumption of each apartment, the following can be provided: heat consumption meters for each apartment system; heat distributors of evaporative or electronic type on each heater; heat consumption meter at the entrance to the building. With any type of heat metering devices, the tenant's payment should include the total heat costs for the building (heating of staircases, elevator lobbies, service and technical premises).
conclusions
In buildings with increased thermal protection of building envelopes, apartment heating systems (with automatic thermostats for heating appliances and heat consumption meters both at the entrance to the building and for each apartment) create additional opportunities and incentives for more efficient use of thermal energy. Due to the automatic control of the heat output of heating devices when the heat load in the premises changes and the ability of residents to regulate the heat output of heating devices, taking into account the mode of residence of the family (reducing the air temperature in the premises during the absence of residents, reducing heat losses), savings in thermal energy from 20 to 30% can be achieved. At the same time, consumers' payment for heat will decrease, since the established norms for the consumption of heat energy significantly exceed the actual consumption.
Description:
Systems used in high-rise buildings can be divided into vertical (riser) and horizontal (apartment, floor wiring). Both of them have both a number of advantages and disadvantages. Vertical (riser) wiring, as a rule, is used in buildings with a single heat consumption accounting (only house accounting).
Experience in the design and operation of apartment heating systems for high-rise residential buildings
Scheme storey node connection of apartment heating and water supply systems to vertical risers
Advantages of apartment heating systems
Compared to vertical riser heating systems, horizontal two-pipe floor-wired apartment heating systems have a number of advantages, mainly from the point of view of the operator and apartment owners.
The apartment system allows the maintenance service to turn off only one apartment, for example, in the event of an accident or if it is necessary to repair or replace heating devices. The heating system of a single apartment can be easily adjusted independently of other apartments. In addition, as noted above, this scheme is not critical to the problem of unauthorized reconstruction of heating systems inside apartments (replacement of appliances and thermostats). The independence of the wiring from other apartments implies the possibility of individual design of heating for each apartment, depending on the wishes of the owner of this apartment. The apartment heating system, if necessary, can be easily equipped with apartment heat meters, which makes it possible to switch to payment for the actually consumed heat energy according to the readings of these heat meters. The installation of heat meters in itself is not an energy-saving measure, however, payment for the actually consumed heat energy is a powerful incentive that forces residents to carry out such measures in the apartment and set the most economic parameters microclimate. For example, during a long absence, it is possible to lower the air temperature in the premises to a certain minimum value by means of thermostats on heating devices. In the current situation, when the cost of heat energy is included in the rent, the owner of the apartment is not interested in saving energy; if the apartment is very hot, the window will be open, but the thermostat will never be closed. The use of apartment heating systems, in comparison with vertical ones, leads to a reduction in the length of main pipes, which always have the largest diameter (the most expensive), a decrease in heat loss in unheated premises where pipelines are laid, and simplification of the floor-by-floor and section-by-section commissioning of the building. The cost of installing an apartment heating system, based on the experience of designing a number of objects, is not much higher than the cost of standard schemes with vertical risers, however, the service life of an apartment heating system is approximately twice as high due to the use of pipes made of heat-resistant polymer materials, thus, the use of this scheme is economically more expedient.
Features of the use of pipes made of heat-resistant polymer materials
Regulatory documents declare the use of apartment heating systems in residential buildings. At the same time, it is allowed to use pipes made of heat-resistant polymeric materials. These can be pipes made of cross-linked polyethylene, polypropylene, fiberglass, metal-polymer, copper, etc. The following requirements are imposed on heating systems with pipes made of such materials:
Apartment heating systems in buildings should be designed as two-pipe systems, while providing for the installation of devices for regulating, monitoring and recording heat consumption for each apartment.
Pipelines of heating systems should be designed from steel, copper, brass pipes, heat-resistant pipes from polymeric materials (including metal-polymer and fiberglass), permitted for use in construction. Complete with plastic pipes, fittings and products corresponding to the type of pipes used should be used.
The parameters of the coolant (temperature, pressure) in heating systems with pipes made of heat-resistant polymeric materials should not exceed the maximum allowable values specified in the regulatory documentation for their manufacture, but not more than 90 ° C and 1.0 MPa.
Pipes made of polymeric materials used in heating systems in conjunction with metal pipes or with instruments and equipment, including in external heat supply systems that have restrictions on the content of dissolved oxygen in the coolant, must have an anti-diffusion layer.
The last statement, in our opinion, is rather controversial, since it is difficult to imagine the diffusion of oxygen inside a pipe in which the medium is under pressure much greater than atmospheric pressure (6–8 atmospheres).
In the apartment heating systems of the objects under consideration (with the exception of the building at 32 Marshala Biryuzova Street, in which polypropylene pipes are used), pipes made of cross-linked polyethylene (PEX) were used. Based on design experience, we can recommend the widespread use of such pipes in mass high-rise construction.
The technology for the production of pipes from cross-linked polyethylene began to spread about thirty years ago. To date, more than 5 billion m of PEX pipes (all types of crosslinking) have already been installed in Europe alone, they account for over 50% of the total market for polymer pipes for plumbing and hot water supply (DHW). The main advantages of using pipes made of cross-linked polyethylene are as follows:
The homogeneity of the wall and the strength characteristics of the material, allowing the installation of water supply and heating systems, including central heating, in high-rise buildings with an estimated service life of at least 50 years, which allows the use of hidden wiring and, in turn, meets modern aesthetic requirements.
The ability to recreate the shape, "molecular memory", allowing to restore the pipeline after a "break" (excessive bending), as well as to operate the system after defrosting.
Reliability of connection of a pipe and a fitting.
A variety of types and a large range of fittings, combined with flexibility and long winding lengths of coils, to minimize the number of connections and pipe waste.
Maintainability of the system: hidden laying of the pipeline in the corrugation (channel), in accordance with the requirements of SNiP, will allow, if necessary, to replace the damaged section of the pipe without opening the wall or floor structure.
Smooth inner surface, which does not allow solid particles to "stick" to the walls - the pipes do not "overgrow", maintaining the internal section; the coefficient of hydraulic resistance decreases in comparison with steel pipes by 25–30%.
It can also be noted that the time and complexity of installation and the number of people employed are much lower than when using steel pipes, the systems are very easy to operate, and their installation does not require specialists of such high qualification as welders.
There are three most common methods for manufacturing modified polyethylene: peroxide (PEX-a), silane (PEX-b), radiation (PEX-c).
The first manufacturer of such pipes, the Swedish company Wirsbo (since 1988 - part of the Uponor concern), entered the market with peroxide technology in 1972, and to date, this company alone has produced 1.2 billion m of PEX-a pipes.
Types of pipes made of cross-linked polyethylene, presented on the domestic market, some manufacturers and a short list of objects in Moscow, in the heating system of which these pipes are used, are presented in Table. one.
| Table 1 Types of XLPE pipes, some manufacturers and examples of objects |
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It should be noted that a major role in promoting the use of XLPE pipes in our country was played by the creation of training centers where special seminars were held for designers. Such centers have been organized by all the leading manufacturers of PEX pipes. In addition, manufacturers offer special software, as a rule, free of charge, allowing you to calculate heat losses and quickly select necessary equipment and design the system.
The difference in crosslinking methods leads to differences in thermomechanical properties. In general, a higher density of the mesh structure, while increasing strength, simultaneously increases the rigidity of the material, making pipes less elastic. The most durable construction is provided by the silane manufacturing method, and at the present time one can note a trend of a steady increase in the market share of pipes manufactured using PEX-b technology. In addition, these pipes are distinguished by a lower price, since they are produced in our country by domestic manufacturers.
The velocity of the heat carrier in the pipes of apartment heating systems made of cross-linked polyethylene is usually taken at the level of values corresponding to economical hydraulic resistances (R = 150–250 Pa/m). At the same time, approximately for the selection of pipe diameters in an apartment heating system with horizontal wiring, it is possible to take the values \u200b\u200bof the speed of the coolant and, accordingly, the heat load at a temperature difference in the supply and return pipelines of 20 ° C, indicated in Table. 2.
It was mentioned above that, according to the requirements of SNiP, the coolant pressure in heating systems with pipes made of heat-resistant polymeric materials should not exceed 1.0 MPa. Theoretically, such a limiting pressure makes it possible to increase the height of the zone. However, XLPE pipes are not designed for such pressure (for example, PEX-a pipes at 90 °C are designed for a maximum pressure of 8.6 atmospheres). For these reasons, apartment heating systems are also zoned vertically, while the height of the zone, as a rule, is limited to 50–60 meters. Most of the facilities described in this article used pipes made of PEX-a manufactured by Rehau, however, the possibilities of using pipes made of cross-linked polyethylene made using other technologies are now being considered, in particular, facilities have already been built where pipes from PEX-b are used, manufactured by Birpex Corporation. The reason for choosing PEX-a for the first objects was their guaranteed reliability and durability: the first buildings with such pipes were built in 1972, and thus we can say that at least thirty years of service life is confirmed by real operation experience. The limitation of the use of PEX pipes lies in the limited combinations of working pressure and temperature.
I would like to draw the attention of designers to the correct selection of pipes in terms of permissible operating pressures and temperatures. As noted above, according to the requirements of SNiP, the pressure and temperature of the coolant in heating systems with pipes made of heat-resistant polymer materials should not exceed 1.0 MPa and 90 °C, respectively. The allowable pressure in the pipe depends, among other things, on the operating temperature and on the diameter of the pipe: for example, pipes 18 x 2 and 18 x 2.5 mm can be offered by the manufacturer, and at the same temperature the first pipe is designed for a pressure of 6 atmospheres , and the second - by 10 atmospheres.
It often happens that after the development of the heating system project, the investor decides to increase the height of the building by several floors, as a result of which the maximum hydrostatic pressure may exceed the allowable one. For example, PEX-a pipes at 90 °C are designed for 8.4 atm, which means a maximum system height of 80 m (theoretically, the height of the system could be made higher, since fittings are designed for 10 atm, and heaters for 16–25 atm ). Therefore, for reliability, in order to avoid exceeding the limiting hydrostatic pressure, it is better to provide an “extra” zone in the building.
Do not overestimate the operating temperature. If the building is designed for 95 ° C, PEX pipes cannot be used in the heating system, since they are designed for a maximum of 90 ° C (the same temperature is indicated in SNiP). Some designers, however, motivate the possibility of using a PEX pipe in this case by the fact that the heat supply schedule is almost never maintained, and this temperature (95 ° C) will never be reached. In our opinion, this opinion is erroneous, and overestimation of the operating temperature should in no case be allowed. When using systems with pipes made of cross-linked polyethylene, it can be recommended to adhere to the temperature schedule of 90-70 ° C, 90-65 ° C, since a further decrease in temperature will lead to a significant increase in the surface of heating devices, which is not welcomed by investors due to the increase in the cost of systems.
Due to differences in the temperature of the heat carrier supplied to the building from urban heating networks, significant foreign experience in operating systems with XLPE pipes can be used in our country to a very limited extent. In countries such as Holland, Denmark, Germany, the coolant is supplied to buildings with a temperature of 70–75 °C. At the facilities under consideration, the condition of XLPE pipes is closely monitored, however, the experience already gained suggests that both during installation and operation of PEX-pipe systems in buildings connected to networks through central heating, there are much fewer problems than for systems with pipes made of other materials.
Another advantage of PEX pipes is the possibility of embedding them in concrete. SNiP allows inextricable connections to be monolithic in concrete. The PEX pipe tension fitting system refers specifically to inextricable connections, unlike other systems: for example, metal-plastic pipes are connected by means of union nuts, so the monolithic installation of such pipes is a violation of SNiP.
The experience of using metal-plastic pipes in heating systems was recognized as unsuccessful, and at present, the use of these pipes in these systems is prohibited by the operation service. During operation, it was found that as a result of aging, the adhesive layer is destroyed and the inner layer of such a pipe “collapses”, as a result of which the flow area changes, and the heating system stops working normally. Such a place is very difficult to detect, usually in this case, the fault is looked for in thermostats, pumps, etc. To detect a fault, a special way, in which a water meter was placed in the line, according to the readings of which it was possible to localize the place of "collapse". In addition to "collapse", in heating systems made of metal-plastic pipes, there have been cases of loss of tightness of union threaded connections due to aging of rubber seals.
One of the significant advantages of XLPE pipes compared to steel pipes is the absence of threaded connections, which significantly increases the reliability of the system. Due to the absence of threaded connections, the number of centers of mechanical stress that appear in threaded connections during heating and cooling of the system. There are cases when, when the hot water supply was stopped for the summer, the pipes began to break along the threaded connections. In systems with pipes made of cross-linked polyethylene, the centers of mechanical stress are evenly distributed along the entire length of the pipes. The factor that plays a role here is that these pipes are supplied in the form of bays, and thus the length of the pipeline without any connections can reach a significant value (for example, 200 m).
It should be noted that the pipes themselves are completely insufficient for installing a heating or water supply system. The system can only be built if the pipe is provided with the necessary assortment of fittings. Not all manufacturers offer a full range of fittings, which forces them to be purchased on the side. This is quite expensive, and, in addition, the fittings of one manufacturer may not match the pipes of another manufacturer, despite the fact that pipe sizes are standardized for all manufacturers. The use of fittings and pipes that do not match each other leads to leaks in the connections, as a result of which leaks may appear in the heating system during operation.
The service life of PEX pipes depends on the temperature of the coolant - the lower this temperature, the longer the service life of the pipe. As noted above, the first such pipes began to be used more than 30 years ago and are currently being successfully operated. Manufacturers indicate the service life of pipes depending on temperature - from 25 to 50 years. These are the minimum figures, in our opinion, the actual service life can be much higher. The inner surface of pipes made of cross-linked polyethylene is always clean, unlike steel pipes, rust, scale, etc. do not accumulate there. Aging of the material of such pipes occurs only as a result of exposure to ultraviolet radiation. Since at the objects under consideration all pipes are protected from sunlight - they are laid in the corrugation, in the floor screed, in the space of the hemmed ceiling, in the grooves - aging and destruction of these pipes does not occur. Heating appliances are connected either through a special socket installed in the wall, or through a standardized metal connection from below.
Types of apartment heating systems
Piping in the heating system of an apartment can be carried out either in the floor or in the space of a false ceiling. At the objects under consideration, as a rule, piping in the floor is used. Because the electrical wiring and various low-voltage lines may also be located in the floor structure, it is necessary to arrange the pipes in such a way that intersections are avoided as much as possible.
Horizontal apartment heating systems are radiant, perimeter and mixed. In municipal residential buildings, the area of one apartment is relatively small. On the other hand, the enclosing structures of modern buildings are distinguished by good thermal protection. Heat losses of apartments are small. In this regard, the heating system is designed for a small heat load, which allows the use of pipes of small diameters. For example, with a thermal load of up to 7 kW, it is sufficient to use a pipe with a diameter of 20 mm. In this case, the apartment wiring is connected directly to the vertical riser in the stair-elevator hall, without any intermediate cabinets, and inside the apartment, a perimeter or mixed wiring is used.
In residential buildings of the elite class, the apartments are usually very large. Stained-glass glazing is often used, arranged winter gardens. Despite good thermal protection, the heat loss of apartments is quite large. Due to the significant heat load in such apartments, it is not always possible to use even pipes with a diameter of 25 mm. In this regard, in residential buildings of an elite class, at the entrance to the apartment of pipes of the heating system, an intermediate distribution cabinet is installed, in which stop valves and air vents are located.
The supply of apartment lockers is provided from distribution manifolds installed in dedicated places of the stair-elevator unit, usually this place is equipped with doors, the key to which is only at the maintenance service. In the same place, as a rule, apartments are connected to water supply systems, and heat and water meters are also installed. Now models of heat meters are offered, the input of which can be given an impulse from water meters, thus reducing the cost of the dispatching system. Even if heat and water meters are not installed, a place is provided for their placement, as well as for laying an information bus.
Inside the apartment, the wiring of heating systems is carried out in the floor, as a rule, according to a beam pattern, although a perimeter one can also be used. These two schemes, radial and perimeter, are generally equivalent. Operating experience has shown that both of them work very well, but still the use of a beam scheme is preferable, especially for large apartments. One of the advantages of beam wiring is the use of smaller diameter pipes. For a large apartment with a perimeter heating system, a pipe with a diameter of 25 or 32 mm is required. In this case, firstly, the preparation of the floor is increased. Second, it increases the cost necessary materials(a large-diameter tee is commensurate in price with the pipe itself). It is much more profitable in such cases, using beam wiring, to increase the number of pipes while reducing their diameter. In this case, since modern sound-absorbing materials of small thickness are used instead of noise-absorbing expanded clay backfill, the floor screed is thinner, which allows you to win in ceiling height and apartment volume (in modern apartments"elite" class, this circumstance is quite significant, since it affects the commercial value of the apartment). The system with beam wiring is easier to install and very convenient to use.
You can easily change the heater of this beam without turning off the other devices. In case of any manipulations with the heating device, for example, during repairs or in the event of an accident, unlike the perimeter wiring, there is no need to stop heating the entire apartment, as a result of which the apartment cools down in winter. With beam wiring, there is no need to make holes in load-bearing walls. When redevelopment of an apartment, the walls can be moved to another place, and the heating lines as well.
If in the process of redevelopment or repair the floor material is fixed around the perimeter of the room, damage to the pipes of the perimeter wiring is possible (such cases were noted during the operation of the building at Marshal Biryuzova St., 32, in which an apartment heating system was used, made according to the perimeter scheme of polypropylene pipes) . On the other hand, if parquet is laid in the apartment, then plywood preparation is used, which is fastened a large number"nails" driven into the screed. In this case, the beam scheme is more vulnerable than the perimeter one. In addition, there were cases when, during the repair process, with the heaters removed, mortars fell into the pipes, which led to their clogging and turning off the heating of the entire apartment. In such cases, it is rather difficult to localize the places of blockages; for this purpose, the maintenance service purchased a set of heating systems. High-altitude zone equipment. To eliminate blockage during perimeter wiring, it is required to turn off the entire apartment. When using beam wiring in such cases, only the branch in which the blockage has occurred is turned off, while it is very easy to detect the blockage site. In the said building, the vertical risers of the heating system are located inside the apartments. These risers were equipped with balance pairs, the system was adjusted, however, the experience of operating the building showed that with such an arrangement of risers in the event of an accident, it is often difficult to get into the apartment to minimize damage. Based on this, at all new facilities, at present, vertical risers of heating and hot water supply systems with the necessary shutoff valves are located in the stair-elevator hall, where they can be accessed by employees of the maintenance service.
The heaters require individual manual or automatic air vent valves, which are also mounted on the distributor.
Hot water system with horizontal apartment wiring
In addition to the heating system, according to such a scheme (with horizontal apartment wiring), hot water supply of a separate apartment can also be organized. This scheme has been successfully implemented, for example, in the Vorobyovy Gory and Triumph Palace high-rise residential complexes.
In this case, the risers of the water supply system are laid in the stair-lift hall, from where hot and cold water pipelines are brought into the apartment. The system is equipped with hot and cold water meters, which, together with filters and pressure regulators, are installed in distribution cabinets in the stair-lift hall. Calculation for actually consumed resources is carried out according to meter readings. This solution allows, if necessary, to cut off one of the consumers, check the pressure, adjust the consumers. The localization of the damaged area allows minimizing the damage from the accident, while the water supply to neighboring apartments does not stop.
In order to avoid the overflow of water from a cold main to a hot one, resulting from improper operation of some types plumbing equipment, at the inputs to the apartments of hot and cold water supply systems are installed check valves. The installation of restrictive pressure regulators of 4 bar is envisaged (for more details, see the article “Experience in designing and operating engineering systems of new high-rise residential complexes in Moscow”, “AVOK”, 2005, No. 2, pp. 8–18).
Wiring to apartments and in the apartment is carried out, as for the heating system, from PEX pipes, usually placed behind false ceiling(maybe in the floor). Since the wiring from the shut-off to the water fittings is carried out without breaks, “with one pipe”, this scheme is characterized by very high reliability and resistance to leaks. In turn, the smooth inner surface of the cross-linked polyethylene pipe makes it possible to avoid “overgrowth” of the pipe even in the case of very hard water. The water supply system is also divided into zones by height, and in the systems described, the risers of the systems are laid in parallel in the above niches of the stair-lift assembly, they have convenient access for maintenance and repair. By analogy with heating systems, all DHW risers are equipped with compensators and fixed supports. The design circulation is set using control and balancing valves. The use of modern regulators makes it possible to use one group of DHW heat exchangers for 2-3 zones in ITP, which is successfully implemented at facilities built according to our projects.
Automatic balancing valves in heating systems
Modern building heating systems are systems that place high demands on reliability and controllability, especially in high-rise and extended buildings. Under such conditions, ensuring hydraulic stability is the main task of both the design and operation of the heating system. Systems must be manageable in all modes and not go beyond effective operation. Traditionally, such controllability is achieved by increasing the resistance of the units of heating devices (radiator and thermostat) and hydraulic balancing of the circulation rings. For this purpose, Danfoss RTD-N radiator thermostats with increased hydraulic resistance are used at the facilities on the piping of heating devices, and on risers or instrument branches of the system, automatic balancing valves of the ASV-P (PV and PV Plus) and ASV-M series ( I). The question arises - how justified is the use of automatic balancing valves in a two-pipe heating system, because manual balancing valves are cheaper. This is not entirely true. In fact, this approach does not take into account the costs that are necessary for setting up and launching a two-pipe heating system with manual balancing valves. Adjustment of systems with manual balancing valves, as a rule, is carried out according to one of the three most common methods: proportional, compensation or computer (using a specialized device PFM 3 000). The description of these techniques is a topic for a separate article, and in this case it is necessary to touch only preparatory phase, which is the same for all methods. Before setting up the system, it is necessary to carry out the following measures: test the system for tightness, rinse and clean the filters, remove air from the system, put the pump into operation (100% load). Set all thermostatic valves to the position corresponding to the design setting (this is the only way to determine overheating and underheating of the premises). To do this, the cap of the thermostatic valve must not rest against the stem. Caps protect the stem from dirt and breakage. Replacement of caps with thermostatic elements is carried out only after completion of adjustment. Carrying out all these activities is possible, in fact, only when adjusting the heating system of a new uninhabited house. After settling, when certain alterations significantly change the hydraulics of the system, even preparatory measures can be significantly hampered.
And one more fact - on average, it takes 20 minutes to adjust one balancing valve. Thus, in branched heating systems high-rise buildings it can take up to 12 hours to set up just one zone. At the same time, when using the first two methods (proportional and compensation), two PFM 3 000 devices are required. Heating systems with radiator thermostats are systems with variable hydraulic characteristics, the resistances of the circulation rings are constantly changing in them. Designed based on 100% system load, manual balancing valves are simply not capable of responding to changes in hydraulic parameters when flow rates decrease. This leads to noise on radiator thermostats, lack of thermal comfort in the premises, and an increase in heat consumption. The operation of thermostats can be transformed from smooth regulation into two-position. The cause of all these problems is the resulting excessive pressure drops in the individual rings and risers of the system, which can differ to a large extent from the calculated ones. Radiator thermostats are often simply not designed for such excessive pressure drops. In addition, a large number of linkage steps of the heating system significantly affects its controllability.
The ASV-P or ASV-PV valves installed on the return line are connected via an impulse tube to the ASV-M valves installed on the supply line and form a differential pressure regulator (direct acting), or together with the ASV-I valve, a differential pressure regulator with the ability to limit spending.
Automatic balancing valves divide the heating system into several independent subsystems. Subsystems can be floor, apartment branches or risers. In the subsystem, a hydraulic regime peculiar only to it is formed, within which hydraulic stability should be ensured. The number of steps for linking the circulation rings in this case depends on the installation location of the automatic differential pressure regulator and the branching of the section of the system regulated by it. The closer the automatic balancing valve is to the radiators, the easier the hydraulic balancing of the system. Absence a large number manual balancing valves reduces the hydraulic resistance of the system and saves the cost of energy for pumping the coolant and improves the thermal comfort in the room. In the presence of automatic differential pressure regulators on unbranched branches, linking circulation rings is reduced to a one-step procedure. The number of circulation rings in such a subsystem is equal to the number of heaters.
For apartment-by-apartment wiring, the best solution is to use automatic balancing valves ASV-P (PV) on the return pipeline and shut-off and measuring valves ASV-I on the supply pipeline. The use of this particular pair of valves makes it possible not only to compensate for the influence of the gravitational component, but also to limit the flow to each apartment in accordance with the design parameters.
Valves are usually selected according to the diameter of the pipelines and adjusted to maintain a pressure drop of 10 kPa. This valve setting value is selected based on the required pressure loss on the radiator thermostats to ensure their optimal operation.
The flow limit per apartment is set by the setting on the ASV-I valves. Moreover, it should be taken into account that in this case, the pressure losses on these valves must be included in the pressure drop maintained by the ASV-PV regulator.
Based on all of the above, the following conclusions can be drawn.
The horizontal apartment wiring of a two-pipe heating system is:
The most protected from unauthorized alterations;
Convenient in terms of operation;
Optimal for organizing commercial metering of heat energy consumption.
Automatic balancing valves:
Divide the heating system into independent subsystems with a stabilized pressure drop;
Eliminate the influence of natural pressure up to the regulated area;
Stabilize the system for a long time;
Provide optimal conditions operation of thermostats;
Simplify hydraulic calculations heating systems;
Do not require expensive system adjustment;
Prevent noise generation;
Allows you to gradually start the heating system.
I would like to hope that the materials of this article will contribute to the transition to apartment heating systems, new materials and equipment. Ready to answer any questions on this topic.
1 See the articles "Engineering solutions for a high-rise residential complex", "ABOK", 2004, No. 5, p. 12–18, and “Experience in the design and operation of engineering systems of new high-rise residential complexes in Moscow”, ABOK, 2005, No. 2, p. 8–18.