Description:
Systems used in high-rise buildings can be divided into vertical (riser) and horizontal (apartment, floor-to-floor distribution). Both have a number of advantages and disadvantages. Vertical (riser) wiring, as a rule, is used in buildings with a unified heat consumption metering (house metering only).
Experience in the design and operation of apartment heating systems in high-rise residential buildings
Diagram of a floor unit for connecting apartment heating and water supply systems to vertical risers
Advantages of apartment heating systems
Compared to heating systems with vertical risers, horizontal two-pipe apartment heating systems with floor wiring have a number of advantages, mainly from the point of view of the maintenance service and apartment owners.
The apartment-by-apartment system allows the maintenance service to turn off only one apartment, for example, in the event of an accident or when 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 suggests the possibility individual design heating of each apartment depending on the wishes of the owner of this apartment. If necessary, an apartment heating system can easily be equipped with apartment heat meters, which allows you to switch to paying for actually consumed heat energy according to the readings of these heat meters. The installation of heat meters in itself does not relate to energy-saving measures, however, payment for actually consumed thermal energy is a powerful incentive forcing residents to carry out such measures in the apartment and set the most economical microclimate parameters. For example, during a long absence, you can lower the air temperature in the rooms to a certain minimum value using thermostats on heating devices. In the current situation, when the cost of thermal energy is included in the rent, the apartment owner 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-by-apartment heating systems, compared to vertical ones, leads to a reduction in the length of main pipes, which always have the largest diameter (the most expensive), a reduction in heat losses in unheated rooms where pipelines are laid, and simplified 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 standard circuits with vertical risers, however, the service life of an apartment heating system is approximately twice as long due to the use of pipes made of heat-resistant polymer materials, thus, the use of this scheme is more economically feasible.
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, the use of pipes made of heat-resistant polymer materials is allowed. These can be pipes made of cross-linked polyethylene, polypropylene, fiberglass, metal-polymer, copper, etc. The current standards impose the following requirements on heating systems with pipes made from such materials:
Apartment heating systems in buildings should be designed as two-pipe systems, providing for the installation of regulation, monitoring and metering devices for heat consumption for each apartment.
Heating system pipelines should be designed from steel, copper, brass pipes, heat-resistant pipes made of polymer materials (including metal-polymer and fiberglass) approved for use in construction. Complete with plastic pipes, you should use connecting parts and products corresponding to the type of pipe used.
Coolant parameters (temperature, pressure) in heating systems with pipes made of heat-resistant polymer materials should not exceed the maximum permissible 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 quite controversial, since it is difficult to imagine the diffusion of oxygen inside a pipe in which the medium is under pressure significantly greater than atmospheric pressure (6–8 atmospheres).
In the apartment heating systems of the objects under consideration (with the exception of the building on Marshala Biryuzova St., 32, in which polypropylene pipes are used), pipes made of cross-linked polyethylene (PEX) are used. Based on design experience, we can recommend the widespread use of such pipes in mass high-rise construction.
The technology for producing cross-linked polyethylene pipes began to spread about thirty years ago. To date, over 5 billion m of PEX pipes (all cross-linking methods) have already been installed in Europe alone, accounting for over 50% of the total market volume polymer pipes for plumbing and hot water supply (DHW). The main advantages of using cross-linked polyethylene pipes are as follows:
The homogeneity of the wall and the strength characteristics of the material allow 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 you to restore the pipeline after a “break” (excessive bending), as well as operate the system after defrosting.
Reliable connection between pipe and fitting.
A variety of types and a large range of fittings combined with flexibility and a long winding length of coils, allowing to minimize the number of connections and pipe waste.
Maintainability of the system: hidden laying of the pipeline in a corrugated channel (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.
A smooth internal surface that does not allow solid particles to “stick” to the walls - the pipes do not “overgrow”, maintaining the internal cross-section; the hydraulic resistance coefficient is reduced by 25–30% compared to steel pipes.
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 simple to operate, and their installation does not require such highly qualified specialists as welders.
There are three most common methods for producing 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 cross-linked polyethylene pipes presented on the domestic market, some manufacturers and a short list of facilities in Moscow whose heating systems use these pipes are presented in Table. 1.
| Table 1 Types of cross-linked polyethylene pipes, some manufacturers and examples of objects |
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It should be noted that the creation of training centers, in which special seminars were held for designers, played a major role in promoting the use of cross-linked polyethylene pipes in our country. Such centers were organized by all leading PEX pipe manufacturers. In addition, manufacturers offer special software, as a rule, free, allowing you to calculate heat loss and quickly select necessary equipment and design the system.
Differences in crosslinking methods lead to differences in thermomechanical properties. IN general case a higher density of the mesh structure, increasing strength, simultaneously increases the rigidity of the material, making the pipes less elastic. The most durable design is ensured by the silane manufacturing method, and currently there is a trend of a confident increase in the market share of pipes made using PEX-b technology. In addition, these pipes have a lower price, since they are produced in our country by domestic manufacturers.
The coolant velocity in the pipes of apartment heating systems made of cross-linked polyethylene is taken, as a rule, at the level of values corresponding to economical hydraulic resistance (R = 150–250 Pa/m). In this case, approximately for selecting the diameters of pipes in an apartment heating system with horizontal wiring, you can take the values of the speed of movement of the coolant and, accordingly, the heat load with a temperature difference in the supply and return pipelines of 20 ° C, indicated in the table. 2.
It was stated above that according to the requirements of SNiP, the coolant pressure in heating systems with pipes made of heat-resistant polymer materials should not exceed 1.0 MPa. Theoretically, this maximum pressure makes it possible to increase the height of the zone. However, pipes made of cross-linked polyethylene are not designed for such pressure (for example, pipes made of PEX-a at a temperature of 90 ° C are designed for a maximum pressure of 8.6 atmospheres). For these reasons, apartment heating systems are zoned vertically, and the zone height is usually limited to 50–60 meters. Most of the facilities described in this article use pipes made of PEX-a manufactured by Rehau, however, the possibility of using cross-linked polyethylene pipes made using other technologies is now being considered, in particular, facilities have already been built that use pipes made of PEX-b, produced by Birpex Corporation. The reason for choosing PEX-a for the first buildings was their guaranteed reliability and durability: the first buildings with such pipes were built back in 1972, and thus we can say that a minimum thirty-year service life is confirmed by actual operation experience. The limitation of PEX pipes is their limited operating pressure and temperature combinations.
I would like to draw the attention of designers to correct selection pipes in terms of permissible operating pressures and temperatures. As noted above, according to SNiP requirements, 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 permissible pressure in the pipe depends, among other things, on the operating temperature and the diameter of the pipe: for example, the manufacturer may offer pipes 18 x 2 and 18 x 2.5 mm, and at the same temperature the first pipe is designed for a pressure of 6 atmospheres , and the second - 10 atmospheres.
It often happens that after developing a heating system project, an investor decides to increase the height of the building by several floors, as a result of which the maximum hydrostatic pressure may exceed the permissible 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 system height could be made larger, since the fittings are designed for 10 atm, and heating devices for 16–25 atm ). Therefore, for reliability, in order to avoid exceeding the limit hydrostatic pressure, it is better to provide an “extra” area in the building.
The operating temperature should not be increased. 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 PEX pipes 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 operating temperature should not be allowed under any circumstances. When using systems with cross-linked polyethylene pipes, it is recommended to adhere to temperature chart 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 rising cost of systems.
Due to differences in the temperature of the coolant supplied to the building from urban heating networks, significant foreign experience in operating systems with cross-linked polyethylene pipes can be used in our country to a very limited extent. In countries such as Holland, Denmark, Germany, coolant is supplied to buildings at a temperature of 70–75 °C. At the objects under consideration, the condition of cross-linked polyethylene pipes is carefully monitored, however, the accumulated experience allows us to say that significantly fewer problems arise during the installation and operation of systems made from PEX pipes in buildings connected to networks via central heating stations. for systems with pipes made of other materials.
Another advantage of PEX pipes is the ability to embed it in concrete. SNiP allows for unbreakable connections to be embedded in concrete. The system of tension fittings for PEX pipes refers specifically to continuous connections, unlike other systems: for example, metal-plastic pipes are connected using union nuts, so embedding such pipes is a violation of SNiP.
The experience of using metal-plastic pipes in heating systems was considered unsuccessful, and currently the operation service prohibits the use of these pipes in these systems. 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 the fault, a special method was developed 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 from 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 cross-linked polyethylene 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 sources of mechanical stress that appear in the threaded connections when the system heats up and cools down. There are known cases when, when the hot water supply was stopped for the summer, pipes began to break at the threaded connections. In systems with cross-linked polyethylene pipes, areas 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 coils, 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 range of fittings. Not all manufacturers offer a full range of fittings, which forces them to be purchased externally. This is quite expensive, and, in addition, fittings from one manufacturer may not correspond to pipes from another manufacturer, despite the fact that the pipe sizes of all manufacturers are standardized. The use of fittings and pipes that do not match each other leads to leaky connections, which may result in leaks 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 minimum figures; in our opinion, the actual service life can be much higher. The inner surface of cross-linked polyethylene pipes is always clean, unlike steel ones, rust, scale, etc. do not accumulate there. The aging of the material of such pipes occurs only as a result of exposure ultraviolet radiation. Since at the objects under consideration all pipes are protected from sunlight - they are laid in corrugation, in a floor screed, in the space of a false ceiling, in fines - aging and destruction of these pipes does not occur. Heating devices 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 an apartment's heating system can be done either in the floor or in the space of the false ceiling. At the objects under consideration, as a rule, pipes are laid in the floor. Since electrical wiring and various low-current lines may also be located in the floor structure, it is necessary to route the pipes in such a way as to avoid intersections as much as possible.
Horizontal apartment heating systems can be radiant, perimeter and mixed. In municipal residential buildings The area of one apartment is relatively small. On the other hand, enclosing structures modern buildings have good thermal protection. Heat loss in apartments is small. In this regard, the heating system is designed for a small thermal load, which allows the use of pipes of small diameters. For example, with a heat load of up to 7 kW, it is enough 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 staircase and elevator hall, without any intermediate cabinets, and perimeter or mixed wiring is used inside the apartment.
In luxury residential buildings, apartments are usually very large. Stained glass glazing is often used, and winter gardens are installed. Despite good thermal protection, heat loss in apartments is quite high. 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 elite class residential buildings, at the entrance of the heating system pipes into the apartment, an intermediate distribution cabinet is installed, in which shut-off valves and air vents are located.
The supply of apartment lockers is provided from distribution manifolds installed in designated areas of the staircase and elevator assembly; usually this place is equipped with doors, the key to which is held only by the maintenance service. In the same place, as a rule, the connection of apartments to water supply systems, and heat and water meters are installed. Models of heat meters are now offered, the input of which can be supplied with an impulse from water meters, thus reducing the cost of the dispatch system. Even if heat and water meters are not installed, space is provided for their placement, as well as for laying the information bus.
Inside the apartment, the wiring of heating systems is carried out in the floor, as a rule, according to a radial scheme, 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 circuit is preferable, especially for large apartments. One of the advantages of beam distribution is the use of smaller diameter pipes. For 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 increases. Secondly, this increases the cost necessary materials(tee large diameter comparable in price to the pipe itself). It is much more profitable in such cases, using radial wiring, to increase the number of pipes while simultaneously reducing their diameter. In this case, since modern sound-absorbing materials of small thickness are used instead of sound-absorbing expanded clay backfill, the floor screed is thinner, which allows for gains in ceiling height and apartment volume (in modern apartments“elite” class, this circumstance is quite significant, since it affects the commercial cost of the apartment). The beam distribution system is easier to install and very convenient to use.
You can easily change the heating device of a given beam without turning off other devices. During any manipulations with the heating device, for example during repairs or in the event of an accident, unlike perimeter wiring, there is no need to stop heating the entire apartment, as a result of which the apartment gets cold in the winter. With radial wiring, there is no need to make holes in load-bearing walls. When remodeling an apartment, the walls can be moved to another location, and the heating routes can be moved as well.
If, during the process of redevelopment or repair, the floor material is attached around the perimeter of the room, damage to the perimeter distribution pipes is possible (such cases were noted during the operation of the building on Marshala Biryuzova St., 32, in which an apartment heating system was used, made according to a perimeter scheme from polypropylene pipes) . On the other hand, if parquet is laid in an apartment, then a plywood preparation is used, which is secured with a large number of “nails” driven into the screed. In this case, the radial scheme is more vulnerable than the perimeter one. In addition, cases were noted when, during the repair process with the heating devices removed, mortars got into the pipes, which led to their clogging and turning off the heating of the entire apartment. In such cases, the places of blockages are quite difficult to localize; the operation service purchased a set of heat shields for this purpose. High altitude zoning equipment. To remove a blockage during perimeter wiring, you need to turn off the entire apartment. When using radial wiring in such cases, only the branch in which the blockage occurred is disconnected, while the location of the blockage is very easy to detect. In the mentioned building, the vertical risers of the heating system are located inside the apartments. These risers were equipped with balance pairs, the system was adjusted, but the experience of operating the building showed that with this 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, vertical risers of heating and hot water supply systems with the necessary shut-off valves are currently located in the staircase and elevator hall, where they can be accessed by maintenance employees.
Heating devices require individual manual or automatic air release valves, which are also mounted on the distributor.
Hot water supply system with horizontal apartment distribution
In addition to the heating system, hot water supply for a separate apartment can also be organized according to this scheme (with horizontal apartment wiring). This scheme has been successfully implemented, for example, in the high-rise residential complexes Vorobyovy Gory and Triumph Palace.
In this case, the risers of the water supply system are laid in the staircase and elevator hall, from where hot and cold water pipelines are introduced into the apartment. The system is equipped with hot and cold water, which, together with filters and pressure regulators, are installed in distribution cabinets in the staircase and elevator hall. Payment 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, and adjust the consumers. Localization of the damaged area allows minimizing the damage from the accident, while the water supply to neighboring apartments does not stop.
To avoid the flow of water from the cold main to the hot one, resulting from improper operation of certain types of plumbing equipment, hot and cold water supply systems are installed at the entrances to apartments. check valves. It is planned to install limiting pressure regulators at 4 bar (for more details, see the article “Experience in the design and operation of engineering systems of new high-rise residential complexes in Moscow,” ABOK, 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 shutdown to the water supply fittings is carried out without breaks, in “one pipe,” this circuit is characterized by very high reliability and resistance to leaks. In turn, the smooth inner surface of the cross-linked polyethylene pipe allows you to avoid “overgrowing” of the pipe even when using 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-mentioned niches of the staircase-elevator assembly and have convenient access for maintenance and repair. By analogy with heating systems, all hot water risers are equipped with compensators and fixed supports. The calculated circulation is set using control and balancing valves. The use of modern regulators makes it possible to use in ITP one group of hot water supply heat exchangers for 2-3 zones, which is successfully implemented at facilities built according to our designs.
Automatic balancing valves in heating systems
Modern building heating systems are systems that place increased demands on reliability and controllability, especially in high-rise and extended buildings. In 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 exceed the limits of effective operation. Traditionally, such controllability is achieved by increasing the resistance of the heating device units (radiator and thermostat) and hydraulically linking the circulation rings. For this purpose, the facilities use Danfoss RTD-N radiator thermostats with increased hydraulic resistance on the piping of heating devices, and on the 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 setup and launch two-pipe system heating with manual balancing valves. Adjustment of systems with manual balancing valves is usually carried out using one of the three most common methods: proportional, compensating or computer (using a specialized PFM 3 000 device). The description of these techniques is a topic for a separate article, and in this case it is necessary to touch only preparatory stage, common for all methods. Before setting up the system, it is necessary to carry out the following measures: test the system for leaks, rinse and clean the filters, remove air from the system, put the pump into operating mode (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 thermostatic valve cap must not rest against the stem. The caps protect the rod from dirt and damage. Replacement of caps on thermostatic elements is carried out only after commissioning is completed. Carrying out all these measures is, in fact, possible only when setting up the heating system of a new uninhabited house. After moving in, when certain alterations significantly change the hydraulics of the system, even preparatory activities may become significantly more difficult.
And one more fact - on average, it takes 20 minutes to set up one balancing valve. Thus, in extensive heating systems of high-rise buildings, setting up just one zone can take up to 12 hours. 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 resistance of the circulation rings in them constantly changes. Designed based on 100% system load, manual balancing valves simply cannot respond to changing hydraulic parameters while reducing flow rates. This leads to noise on radiator thermostats, lack of thermal comfort in the premises, increased heat consumption. The operation of thermostats can be transformed from smooth regulation to on-off regulation. The cause of all these problems is the resulting excess pressure drops in individual rings and risers of the system, which can differ greatly from the calculated ones. Radiator thermostats are often simply not designed for such excessive pressure drops. In addition, the large number of connection stages of the heating system significantly affects its adjustability.
Valves ASV-P or ASV-PV, installed on the return line, are connected via an impulse tube with valves ASV-M, installed on the supply, and form a differential pressure regulator (direct action), or together with valve ASV-I - a differential pressure regulator with possibility of limiting consumption.
Automatic balancing valves divide the heating system into several independent subsystems. Subsystems can be floor, apartment branches or risers. In the subsystem, a characteristic characteristic only of it is formed hydraulic mode, within which hydraulic stability should be ensured. The number of stages of linking the circulation rings in this case depends on the installation location of the automatic differential pressure regulator and the branching of the system section it regulates. The closer the automatic balancing valve is to the heating devices, the simpler the hydraulic linkage of the system. The absence of a large number of manual balancing valves reduces the hydraulic resistance of the system and saves the cost of energy for pumping coolant and improves thermal comfort in the room. If there are automatic pressure differential regulators on unbranched branches, linking the circulation rings is reduced to a one-step procedure. The number of circulation rings in such a subsystem is equal to the number of heating devices.
When distributing apartments to apartments, the optimal 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 rate for each apartment in accordance with the design parameters.
Valves are usually selected according to the diameter of the pipelines and are set to maintain a pressure drop of 10 kPa. This valve setting value is selected based on the required pressure loss on 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 loss on these valves must be included in the pressure difference maintained by the ASV-PV regulator.
Based on all of the above, the following conclusions can be drawn.
Horizontal apartment wiring of a two-pipe heating system is:
The most protected from unauthorized alterations;
Convenient from the point of view of operation;
Optimal for the organization commercial accounting thermal energy consumption.
Automatic balancing valves:
Divide the heating system into independent subsystems with a stabilized pressure difference;
Eliminate the influence of natural pressure up to the regulated area;
Stabilizes system operation for a long time;
Provide optimal conditions operation of thermostats;
Simplify hydraulic calculations of the heating system;
Does not require expensive system setup;
Prevent noise generation;
Allows you to gradually start up the heating system.
I would like to hope that the materials in this article will contribute to the transition to apartment heating systems, new materials and equipment. We are ready to answer any questions you may have 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.
The level of heat supply directly depends on the type of wiring of the heating system in an apartment or house. The most common schemes are single-pipe and two-pipe horizontal heating systems.
Types of wiring
Heating system design
In any apartment all the elements heating system are connected according to one scheme or another. The pipeline can be routed vertically or horizontally.
In the first case, the main sun lounger is located in the basement. Riser pipes of smaller diameter extend from it, to which pipes and radiators in the apartment are connected. The main advantage of vertical wiring is its low cost and simplicity.
Vertical layout
A single-pipe vertical system can have top or bottom wiring. Both types have their own technical characteristics. When installing a single-pipe vertical system with overhead pipe distribution, the supply pipeline is laid in the attic or on the technical floor. From the sun lounger, the coolant is supplied to the apartments through series-connected risers.
Such a system is static. It will not be possible to scale it by changing the number of radiators and installing regulators. It can save pipes during installation, but requires the installation of a large number of heating devices. Single-pipe vertical systems are well suited for projects that involve natural circulation of coolant.
A two-pipe system with bottom wiring has a supply pipeline and a return line. They are laid on the floor surface or in the floor, for example, in a screed. When implementing such a system, the coolant enters each battery independently. This scheme is not without nuances. Each radiator must have a tap through which air can be vented.
Unlike single-pipe systems, two-pipe systems are adjustable circuits. Communications built in this way make it possible to turn off any heating device in the network. Overconsumption of radiators is also not typical for them, but total length there will be significantly more pipelines compared to a single-pipe scheme. IN apartment buildings The two-pipe system has one more nuance. It is almost impossible to install an individual heat meter here. And the use of communal heat meters is beneficial mainly for residents of the first floors.
Horizontal layout
The basis of the horizontal distribution is the supply riser, passing through all floors. Sun loungers are connected to the riser, supplying heat to individual apartments. The use of horizontal wiring requires careful insulation of the riser, since significant heat loss occurs here. To reduce heat loss as much as possible, risers are often installed in specially equipped shafts.
Single-pipe circuits have a narrow scope of application - heating large areas. Therefore, they are almost never installed in residential buildings. Horizontal two-pipe system good for providing warmth apartment buildings.
Installation of a two-pipe heating system in general outline as follows:
- From the main supply riser, a supply and return pipe are laid on each floor, and radiators are also connected.
- Shut-off valves are installed on all radiators, without exception.
An important advantage of the scheme is the possibility of connecting/disconnecting heat on a floor-by-floor basis. Sunbeds can be laid in the floor screed. This scheme allows the use of radiators with bottom connection. All this has a good effect not only on heat supply, but also on the aesthetic appeal of apartments. One more thing should be noted important fact- possibility of installing individual heat meters.
For all its undeniable advantages, the system is not ideal. The difficulty lies in the need to install compensators for a significant length of the main line. The operation of the system as a whole becomes more complicated, since the installation shut-off valves and air valves are required on every radiator without exception.
Collector wiring
Heating wiring diagram in a private house
It is worth mentioning separately about another popular wiring scheme - this is a two-pipe manifold floor-to-floor system. Its peculiarity lies in the installation of supply and return manifolds on each floor. As in the case of the already described option, the heart of the system is the common supply riser. At large quantities consumers in the house are allowed to install several risers. On each floor, two collectors are installed - supply and return, and from them there are pipelines supplying coolant to the radiators.
Unlike traditional options, the collector floor scheme has a significant pipeline length. Considering that metal-plastic pipes are used for installation of the circuit, the implementation of such a project turns out to be more expensive than conventional options.
Important! Despite this drawback, collector circuits, from the point of view of operational features, are much more efficient and simpler than other options. This makes them increasingly popular not only in multi-storey buildings, but also in individual construction.
The two-pipe collector system guarantees an even supply of heat to all rooms. For comparison, it is worth remembering the operating principle of single-pipe circuits. In them, heat is supplied and removed through one pipe, and radiators are connected in parallel. As it moves through the pipeline, the coolant cools down. As a result, the further the radiators are located from the supply pipe, the colder the water in them, and, as a result, the lower the air temperature in the room. It is impossible to install regulators in such connection diagrams. Therefore, even within the same apartment it is impossible to achieve uniform heat.
Two-pipe circuits make it possible to reduce this disadvantage to a minimum. The cooled coolant is removed from the system via the return line. The water does not cool down as it moves from radiator to radiator, which means that all rooms will have approximately the same temperature. Such thermal indicators provide the most comfortable microclimate in the apartment. We must not forget that in such systems it is possible to install temperature regulators. And this gives not only comfort, but also savings and efficient use of funds. In general, the installation of an expensive collector circuit pays for itself within 2–3 heating seasons.
Features of the collector circuit
Installation of heating systems
Important differences between two-pipe beam (collector) systems are:
- Flexibility and scalability of the scheme.
- Possibility of installing thermostats on each radiator.
- The need to ensure forced circulation of the coolant using circulation pumps.
- Each circuit is a separate system with additional equipment and automation.
- There is no need to install air vents on radiators.
- High system reliability, reduction in the number of accidents and leaks.
- High resistance to water hammer.
- Aesthetics
We can talk about the economic and operational advantages of horizontal two-pipe collector systems for a very long time, but we cannot fail to note another advantage of them - aesthetics. Modern man values comfort. Even inexpensive renovations are done, if not with the involvement of a designer, then at least using the latest design trends. The presence of risers throughout the apartment does not go well with modern design. In old houses, the issue of risers is aggravated by another significant problem - constant smudges and leaks that can kill even the best and most expensive repairs.
Installation of heating systems
In two-pipe collector circuits ah, all pipelines are laid in the floor screed. Not only do they not spoil the apartment, they are absolutely invisible. Laying pipes in a screed is possible thanks to the use of modern materials - plastic and metal-plastic. They are not subject to corrosion, are not afraid of low temperatures and even freezing of the coolant.
Horizontal radial patterns also make it possible to ensure truly high comfort in each room thanks to the possibility of installing heat regulators. The temperature of the house is regulated depending on the weather outside the window. The result is a highly energy efficient system.
Conclusion
Among all existing heating network installation schemes, the best option remains a horizontal radial two-pipe system. Despite more high cost installation, it is becoming increasingly popular not only in multi-storey buildings, but also in private housing construction. This popularity of collector circuits is explained by a unique combination of excellent technical, operational, economic and aesthetic indicators.
There are two pipe distribution systems through which coolant is pumped for heating apartments in an apartment building. Vertical and horizontal wiring system. How they differ from one another will be written in this article. Here's what they look like:
Vertical layout single-pipe:
Vertical two-pipe distribution:
Each radiator in these pictures symbolizes a separate room in the apartment. Such pipe routing systems were installed in Soviet times mainly because they allow significant savings on pipes. Now we will not talk about other advantages and disadvantages of such systems, but let’s say the main thing.
In a single-pipe vertical distribution system, install a thermal apartment meter Unfortunately, it will be difficult. In a two-pipe vertical heating system, installing a heat meter is sometimes possible, although this will be doubly difficult. Here the heat meter will have to be in each of your rooms. How many rooms - so many counters. Places for possible installation of heat meters are shown in the figure above.
The difficulty in installation will also lie in the fact that you will encounter very strong resistance from the management company. They will be categorically against installing heat meters. If you have the strength and patience to resist them, fight. The struggle is worth it.
By the way, many people ask a strange question - if there is a heated floor in an apartment or private house, in other words, there is a connection of a heated floor to the heating system of a private house or apartment building, how will this affect the readings of the heat meter? The answer is very simple - no way. A warm floor is actually an ordinary heating radiator that is already installed in a house or apartment. The heat consumption that will occur through this heated floor will be summed up with the heat consumption that occurs through the heating radiators. That's all.
Horizontal wiring of perimeter type:
Horizontal radial layout:
Recently, horizontal distribution in heating systems has been installed in many new apartment buildings. If you have horizontal wiring of any type, you can definitely install an individual heat meter in your apartment. There will be less resistance from the Criminal Code to do this, but they will still exist. Be prepared for this.
The heat meter must be installed on the direct or return pipelines of the apartment. Right place installations - immediately, where the pipes of the supply (direct) and return pipelines of the apartment cut into the main risers of the house.
Vertical wiring of the heating system is used in both autonomous and centralized heating networks. According to the method of transporting the working medium through the pipeline, it can be natural or forced circulation. In the first case, the coolant moves due to the difference in density. In low-rise buildings with an autonomous heating network with forced circulation, the movement of the working medium occurs due to the pump, and in the presence of centralized communications - due to pressure drops.
According to the coolant supply option, the following vertical heating systems are distinguished:
- with top wiring. The pipeline for such networks is laid in the attic or under the ceiling;
- with bottom wiring. Installation of lines for transporting the working fluid is carried out through the basement or in the floor screed.
Compared to a horizontal heating system, a vertical heating network is not prone to the formation of air pockets and allows you to control the temperature of the batteries. TM Ogint offers a large selection of thermostatic valves and thermostatic elements, with the help of which you can establish and maintain a comfortable microclimate in the room.
Depending on the nuances of the design, the vertical heating network can be single-pipe or double-pipe. When choosing a certain type of system, take into account the number of floors of the building and the need for installation individual devices heat metering.
Single pipe vertical system
A single-pipe vertical system is characterized by coolant circulation in a closed loop. When installing such a heating network, radiators are connected in series, so there is a significant difference between the degree of heating of the first and last batteries. However, this disadvantage can be compensated for by the short length of the highways.
For additional adjustment, heating devices of single-pipe systems are equipped with various types of pipeline fittings. In the range of TM Ogint it is represented by the following devices:
- thermostatic kits;
- shut-off valves allowing autonomous repair without shutting down the entire network.
To ensure the efficient functioning of a single-pipe circuit with natural circulation, it is advisable to install a Mayevsky valve with a cap for a screwdriver or another type of air vent on the heating radiators.
The advantages of a vertical single-pipe network include:
- minimal consumption of materials;
- the optimal amount of coolant, the volume of which can be adjusted by selecting the diameter of the pipes;
- possibility of installing the system without using a circulation pump.
However, it is effective for small rooms, and to heat rooms with an area of 40 m2 or more, you will have to install several risers, otherwise it will be difficult to achieve comfortable temperature. Therefore, installation of a single-pipe vertical system is advisable in apartment buildings with a height of at least 5 floors. In addition, it is necessary to have good insulation and small rooms.
Two-pipe vertical system
A vertical two-pipe heating system involves the installation of two lines for transporting the coolant. One of them carries heated working environment, and the second performs the function of removal after cooling. Since the radiators are connected in parallel, it is necessary to ensure that the pipelines are laid next to each other.
An additional line increases the cost of materials and the volume of coolant, for the movement of which natural circulation is not enough, since hydrodynamic resistance increases. For efficient operation, autonomous engineering heating systems in private cottages are equipped with powerful circulation pumps.
According to the method of supplying coolant, two-pipe networks are usually with top wiring. This option for organizing heating is more efficient and requires less effort during installation. A system with bottom wiring is labor-intensive to install and difficult to operate the equipment.
The use of a vertical two-pipe scheme in multi-apartment buildings provides the following advantages:
- the ability to supply coolant with the same degree of heating to all heating devices, regardless of the floor;
- ease of flushing and carrying out preventive maintenance when preparing the pipeline for operation.
A heating network of this design is almost not prone to the formation of air jams. To completely eliminate the likelihood of their occurrence, you can install one of the air vent options offered by TM Ogint. For radiators, a Mayevsky tap is sufficient, but for the entire system an automatic device will be required.
In the context of rising tariffs for heating housing in multi-apartment buildings, it is important to not only regulate the temperature, but also control the heat consumption. A two-pipe vertical heating system allows the installation of in-house heat metering devices. The use of individual heat consumption meters in each apartment is complicated by the peculiarities of legislation and the need to install the device on each riser.
The range of heating equipment TM Ogint allows you to select components for installation vertical systems different types. A large selection of thermostatic and shut-off valves, as well as other types of pipeline fittings, makes it possible to create an effective heating network at minimal cost. High quality products ensure the functioning of heating systems for a long time.
The efficiency of heating is largely determined by correctly selected components - the boiler, pipes with the appropriate diameter, radiators and shut-off valves. However, in addition to this, the location of the highway must be taken into account. What is the difference between a horizontal heating system: two-pipe, one-pipe, wiring and connection of heating devices? In order to determine the feasibility of designing and installing such a scheme, you must first consider its specifics.
Features of the horizontal pipe laying scheme
In the overwhelming majority, a horizontal two-pipe heating system with bottom wiring is installed in one or two-story private houses. But, in addition, it can be used to connect to centralized heating. Feature similar system is the horizontal arrangement of the main and return (for two-pipe) lines.
When choosing this piping system, it is necessary to take into account the nuances of connecting to various types heating.
Central horizontal heating
To draw up an engineering diagram, you should be guided by SNiP 41–01–2003. It states that the horizontal distribution of the heating system must ensure not only proper circulation of the coolant, but also ensure its metering. For this purpose, two risers are installed in apartment buildings - with hot water and for receiving cooled liquid. A calculation of a horizontal two-pipe heating system, which includes the installation of a heat meter, is required. It is installed on the inlet pipe immediately after connecting the pipe to the riser.
In addition, the hydraulic resistance in certain sections of the highway is taken into account. This is important, since the horizontal distribution of the heating system will only work effectively if the appropriate coolant pressure is maintained.
In most cases, for multi-apartment buildings, a single-pipe horizontal heating system with bottom wiring is installed. Therefore, when choosing the number of sections in radiators, you need to take into account their distance from the central distribution riser. The farther the battery is located, the larger its area should be.
Autonomous horizontal heating
In a private house or apartment without a connection to the central heating supply, a horizontal heating system with bottom wiring is most often chosen. However, it is necessary to take into account the operating mode - with natural circulation or forced under pressure. In the first case, a vertical riser is installed immediately from the boiler to which the horizontal sections are connected.
The advantages of this arrangement for maintaining a comfortable temperature level include the following:
- Minimum costs for purchasing consumables. In particular, a horizontal single-pipe heating system with natural circulation does not include circulation pump, membrane expansion tank and protective fittings - air vents;
- Reliability of operation. Since the pressure in the pipes is equal to atmospheric pressure, the excess temperature is compensated using an expansion tank.
But there are also disadvantages to be noted. The main one is the inertia of the system. Even a well-designed horizontal single-pipe heating system two-story house with natural circulation will not be able to provide rapid heating of the premises. This is explained by the fact that the heating network begins to move only after reaching a certain temperature. For houses with a large area (from 150 sq. m.) and with two floors or more, a horizontal heating system with bottom wiring and forced circulation of liquid is recommended.
Unlike the scheme described above, there is no need to make a riser for forced circulation. The coolant pressure in a horizontal two-pipe heating system with bottom wiring is created using a circulation pump. This is reflected in improved performance:
- Fast distribution hot water along the entire highway;
- Possibility of adjusting the volume of coolant for each radiator (only for a two-pipe system);
- A smaller area is required for installation since there is no distribution riser.
In turn, horizontal wiring of the heating system can be combined with a collector one. This is relevant for long-distance pipelines. This way you can achieve even distribution of hot water throughout all rooms of the house.
When calculating a horizontal two-pipe heating system, it is necessary to take into account the rotary units; it is in these places that the hydraulic pressure losses are greatest.
Single-pipe horizontal heating system
What is horizontal heating distribution in combination with a single-pipe system, in what cases can it be installed? Among experts, it is considered the easiest to install and the most affordable. The principle of its design is that radiators are connected to the pipeline in series. Depending on the selected configuration, the connection of the pipes can be top or bottom.
But at the same time, the horizontal single-pipe heating system of a two-story house has the following disadvantages:
- Uneven heat distribution across the batteries. The further the radiator is from the boiler, the lower the water temperature in it will be;
- Difficulties in performing repair and maintenance work. When disconnecting the radiator from the general network in a horizontal single pipe system heating with natural circulation, the flow of coolant further through the pipeline stops;
- Inability to regulate temperature in various rooms Houses.
During the design of this system, it is imperative to install a bypass in front of each radiator. In combination with shut-off valves, it will allow you to perform renovation work or replacement of individual heating elements.
For effective heat transfer, the batteries must be 2/3 covered by the window sill. This will promote optimal air convection in the room.
A single-pipe horizontal heating system with bottom wiring is installed only in houses with small area– up to 150 sq.m. You also need to take care of additional thermal insulation of those rooms that are farthest from the boiler.
Two-pipe horizontal heating system
For a horizontal heating system with bottom wiring, all of the above disadvantages are absent. This is possible thanks to a different scheme for connecting radiators to pipelines. Each device is connected in parallel. The hot coolant flows through the tee assembly, and the cooled coolant flows directly into the return pipe.
In this way, you can regulate the volume and flow rate of the coolant for each radiator. In addition, in contrast to a single-pipe horizontal heating system with bottom wiring, the improved scheme has the following advantages:
- Installing additional heating devices will not affect the system. The main thing is that the boiler’s power allows it to heat an increased volume of coolant;
- Repair and maintenance work can be carried out without turning off the heating. To do this, it is enough to use shut-off valves to shut off the coolant at in the right area networks;
- If you install distribution manifolds together with a horizontal two-pipe heating system with wiring from below, you can increase the efficiency, thereby minimizing energy costs.
The disadvantages of two-pipe heating with horizontal wiring include the high likelihood of air locks. To avoid this, a Mayevsky tap is installed on each radiator. With a large branched network, a calculation is performed for a horizontal two-pipe heating system. It should include the magnitude of the pressure drop at each site, as well as the change in water temperature. It is difficult to do this work yourself without the proper skills, so it is best to use a professional online calculator, or seek the help of specialists.
After the last, most distant radiator, it is recommended to install a pressure gauge and an air vent. This set of measures will allow you to avoid sudden pressure surges in the system and make it possible to visually monitor its parameters.
Features of the package
While installing the horizontal single-pipe heating with natural circulation, the angle of inclination of the pipes should be observed. It is performed towards the radiators in the direction of water movement. The lowest point of the return line must not be below the boiler level. It should be remembered that any horizontal heating distribution is characterized by increased resistance - the larger the diameter of the pipe, the higher this figure.
The two-pipe system must include a circulation pump and a membrane expansion tank. Without these elements safe work heating is not possible. Also installed measuring instruments– pressure gauges and thermometers.
So which horizontal heating system should you choose - two-pipe or single-pipe? This is determined by the characteristics of the house. For buildings with a large area, it is recommended to install two-pipe distribution with forced circulation. If the speed of heating the air in the rooms and the ability to regulate the temperature are not important, you can install single-pipe heating.
An example of calculating one-pipe heating - hydraulic losses: