How does a closed heating system work? feature of a closed system. Closed systems diagrams
That is a diagram of a certain connection of various devices and equipment. It is done in a strict order. The coolant also moves in only one direction, and its change is impossible. After all, the laws of physics apply when heated water rises, and cooled water falls. There is only one BUT. There are two that differ from each other in closedness and tightness. Many experts believe that a closed heating system is more efficient. Is it so? Let's try to figure it out.
Feature of a closed system
To understand how a closed system differs from an open one, let's first deal with expansion tanks.
This is a container made of metal or plastic. Install it at the top of the system, as high as possible. It performs a dual function:
- Firstly, it creates a slight pressure inside the pipelines.
- And, secondly, it collects excess coolant after it heats up. After all, liquids expand with increasing temperature, and this is the law of physics.
An open system differs from a closed one in that the coolant in the expansion tank comes into contact with air. In the second system, everything is sealed, and there is no contact.
Why such difficulties? There is one positive aspect to this case. Circulation pumps are installed in many heating networks of private houses, which increase the efficiency of the system by evenly distributing the coolant over the heating radiators. This results in fuel economy and therefore Money from the family budget. BUT circulation pump can only work in a closed system.
A small digression. Installation of a warm floor in private homes is possible with a pump device - without it, this system will work, but not as efficiently as we would like. So, if you decide to install a "warm floor" in your house, you simply must accept it.
However, the installation of a circulation pump makes heating dependent on the energy supply. That's right - there will be small costs, but they will be covered by savings in the main fuel, and several times over.
Attention! It is necessary to install the pump on the coolant return flow line. This is done for the sole purpose of protecting the rubber parts of the pump (cuffs, o-rings and seals) from high temperatures. Immediately near the pump, it is necessary to place risers that connect the line to the expansion tank.
Advantages of a closed heating system
Setting up a connection
Of course, the costs of purchasing and installing a circulation pump are significant, but the system only benefits from this device. What are the advantages of this option?
- Installation is simplified due to the fact that there is no need to set the angles of inclination of the mains, and thermal insulation of pipelines is not needed.
- The cost of installation is reduced due to the use of pipes of a smaller diameter. Indeed, in an open circuit, the larger the volume of water inside, the better. In a closed system, there is no such dependence.
- The coolant does not evaporate, which allows not to control its level and does not require periodic replenishment. In addition, in a closed system, the heating of the coolant occurs much faster. BUT hot water evenly distributed over all radiators, regardless of the wiring diagram.
- The service life of the heating boiler is increased by reducing the difference in the coolant in the supply and return lines. Corrosion processes are also reduced due to high tightness.
- It becomes possible to use not water, but antifreeze as a coolant.
- The process of heat transfer increases.
Does the system have disadvantages? There are, but not many. The first is energy dependence, since the pump is connected to the power supply network. The second is volume. expansion tank must be greater than in the open loop. Experts recommend taking a tank with a volume equal to 10% of the volume of the coolant. Therefore, the cost of such a tank can be quite high.
Elements of the heating circuit
Components of the system
Let's list what nodes the closed heating system of a private house consists of. Only a few distinguish it from open additional devices and a modified design of the expansion tank.
As usual:
- this is a boiler;
- pipes;
- fitting;
- shut-off valves;
- heating batteries;
- sometimes a distribution manifold;
- membrane expansion tank;
- circulation pump.
At the same time, you can save on the diameter of pipes, fittings and valves, although a circulation pump is added. A membrane expansion tank can only be purchased ready-made, but in an open system, you can use self-made tanks. That is, the pros and cons overlap each other.
How does a closed heating circuit work?
Everything is quite simple and traditional. The coolant heats up in the system, expands, and its excess moves to the expansion tank. It is a sealed capsule divided into two parts. The lower one is a hydraulic chamber where the coolant enters. The upper one is a gas chamber, which is filled with nitrogen at a certain pressure at the factory.
Installing an additional pump
Before starting the boiler and heating the water, the pressure in the expansion tank is equal to the pressure of the coolant in the circuit. As soon as heating begins, the coolant fills the lower chamber, squeezing out nitrogen through the membrane to the upper plane of the tank. Nitrogen is compressed and its pressure rises. This equalizes the pressure in the circuit and the expansion tank, and it becomes equal to the nitrogen pressure.
Everything else follows the old pattern. The coolant passes through all heating lines and returns to the heating boiler. And all this is due to the fact that the circulation pump works.
Design features
- Firstly, all structural elements of heating can be placed in one room. This is a boiler, and a pump, and an expansion tank. In this case, there is no need to raise the tank to a great height. After all, two elements create pressure in the circuit - this is a pump and nitrogen inside the tank. All this gives several advantages - reducing the diameter of the pipelines, non-observance of the angles of inclination, and the absence of evaporation of the coolant.
- Secondly, it becomes possible to use such a scheme in houses with a large area and volume. With an open system, it will be very difficult to achieve efficient heating in a large house.
Boiler and separator
There is a question that today worries a certain part of the developers of private houses. It's about remodeling open circuit in closed. There are no problems in this regard. No need to change pipes and other elements, you just need to insert a circulation pump into the return circuit and change the expansion tank by installing a membrane model.
But won't air pockets form at the slopes of the pipelines? There is such a possibility here, it is important to choose the power of the pump and the dimensions of the expansion tank. If everything is normal, then air will be pushed under the pressure of the coolant.
Installation of a closed heating system
Immediately make a reservation that there is no difference - you are assembling an open or closed circuit. You will have to face all the difficulties of such work. And if you are in any doubt, then entrust the installation to specialists. The most important thing here is to choose the right components and devices so that they correspond to the required indicators and parameters. This is especially true for the heating boiler, radiators, pump and expansion tank. Let's not forget the pipes - in a closed circuit, their inner diameter can be equal to 20 millimeters.
The best option is to organize a separate boiler room if it comes to heating a large house, and you can’t do without a floor boiler. If the house is small, then the wall-mounted unit will cope with the task of heating, and its design already has both an expansion tank and a circulation pump. In addition, you do not have to mount it in a separate room - the kitchen is also suitable for this.
Filling heating with coolant
Boiler room in the basement
So, the installation is completed, and now it is necessary to check and start the system. To do this, you need to fill it with water. There are two options here. The first is to connect to the water supply by installing locking device in the form of a faucet, valve or valve. This method is relevant if a single-pipe wiring diagram is selected. But if the water pressure in the water supply is sufficient, then it can also be used in a two-pipe scheme.
The second - with the help of a bucket and own hands. To do this, you will have to bring out a riser equipped with a funnel and a sealed plug above all the elements. Remove the plug, install the funnel, pour water into the system, after filling, remove the funnel and install the plug in place. A plug is an element made in the form of a cap with threaded connection and a rubber gasket in the depth of the cap. Accordingly, the riser must be equipped with a drive with an external thread. True, filling the coolant manually requires both time and effort.
So the system is full. Now you need to walk around the entire circuit and inspect all joints and connections without exception for leaks. If there are none, then you can turn on the pump and check again for leaks. If everything is normal again, you can light the boiler. But the testing doesn't stop there. When the coolant reaches the required temperature, we check the lines again.
Recommendation! Before starting the heating, it is necessary to carry out a pressure test with a pressure one and a half times greater than that created by the pump. This is especially needed if a "warm floor" is connected to the heating system. It will be walled up, so it is very difficult to carry out repairs after finishing.
Filling with coolant
How to properly crimp? To do this, you need a special pump - electric or manual. Connect it through the valve, increase the pressure inside the circuit and close the valve. The system should be in this state for some time - it will show exactly whether there are leaks or not. After that, open the valve and lower the pressure by lowering part of the coolant.
Conclusion on the topic
When arranging a closed heating system, it is necessary to take into account all the aspects that were discussed above. Of course, this system is better, but if you are the happy owner of a small house, then there is no need to fence all this. Use diagrams in a simpler way and with fewer different elements. This will not only simplify the installation process, but also reduce a significant part of the costs associated with building a house as a whole.
In such a network, the pressure is maintained at the same or close level, there is no need for constant monitoring of the amount of coolant. A properly designed scheme allows you to heat a house of any size, and when choosing a double-circuit boiler, provide it with hot water.
What's going on inside?
In a closed system, a closed cycle of coolant movement is used. One has only to fill the pipes with water once, so as not to worry about its quantity later. The following equipment is used: a heating boiler, pipelines and heating sources.
Having heated up in the boiler to the required level, the coolant begins to fill the pipeline. As the heated water passes through pipes and radiators, the latter are heated. As they cool, they release their heat to the air. The cooled water is returned to the boiler. The cycle repeats itself: in the heating system closed type liquid is constantly circulating through the pipes.
What does it consist of?
closed system heat supply consists of the following components:
- heating boiler;
- membrane expansion sealed tank;
- circulation pump;
- radiators and heating batteries;
- pipes used for the installation of highways, risers, jumpers and piping;
- fittings;
- taps (plug and ball) and Mayevsky valves;
- filters that allow you to remove various contaminants from the circulating coolant, as well as prevent the formation of blockages;
- fasteners (clamps, etc.).
Principle of operation
The heat carrier (water or antifreeze) is heated in a heating boiler. As the temperature rises, the volume of the liquid increases. The excess coolant that has appeared through a special valve enters the expansion tank, which consists of two compartments: a hydraulic and a gas chamber. The first is designed to receive excess heated liquid. The second contains nitrogen at a pressure equal to the pressure of the hydrostatic circuit.
As the coolant enters, the volume of the gas chamber begins to decrease, which accordingly leads to an increase in gas pressure. As soon as the temperature of the coolant begins to decrease, it returns back using a special pump. As a result, it is possible to keep the pressure within a strictly specified range.
When using a non-pressure tank, its 100% filling with coolant is permissible. This system, compared to the membrane tank is more compact in size.
Open or closed?
Unlike an open system, all elements are sealed in a closed system. As a result, there is no evaporation of the liquid and heat transfer increases, you have to spend less money on heating maintenance. In the open, you have to constantly monitor the water level. Antifreeze is not used in such systems.
Thanks to forced circulation, it is possible to increase the rate of passage of the coolant through the pipes.
This reduces the difference between the temperature at the inlet and outlet of the heating boiler, which in turn leads to an increase in the service life of the latter. At the same time, the time spent on heating all rooms is reduced: filling the system with hot coolant is faster. In an open system, pipes and radiators warm up more slowly.
No contact between coolant and environment helps to reduce the oxygen concentration in the liquid. The pressure in a closed system fluctuates in a narrow range, contributing to the deaeration of the coolant. As a result, due to tightness, corrosion processes inside heating devices are significantly slowed down.
Meanwhile, a closed system with forced circulation is volatile, which is not always convenient if a private house is located in an area with frequent power outages. In addition, its installation is much more expensive, since you have to purchase a larger expansion tank than for open system.
When choosing the right type, it is worth considering that the open system is ideal for small spaces. It is often mounted in cottages. For a private house of a large area, it is better to choose a more modern closed type of heating.
Mounting
Installation work includes several stages. Consistency must be followed to ensure proper quality.
We are preparing the site
Installation work begins with the preparation of a place or a separate room intended for the installation of a heating boiler.
It is preferable that this work be carried out by representatives service center. Doing everything on their own, it is necessary to ensure the correct spatial arrangement of the equipment.
We mount pipes
From the boiler installation site, the pipeline is laid to the places where the radiators are planned to be placed. When performing installation, the approved scheme must be taken into account. If pipes are to be laid through the walls, a hole of sufficient diameter is drilled. After completion of work, the hole is covered with cement mortar.
When connecting pipes, the composition of the material from which they are made should be taken into account. Copper must be soldered, steel must be welded. Special fittings are used to connect metal-plastic pipes. Polypropylene products are connected at a facility designed for their welding.
An autonomous heating system in which the coolant is driven by a circulation pump is called a closed or closed heating system. Its characteristic feature is absolute tightness and the absence of contact of the coolant with the environment.
The expansion tank in it is also closed, membrane type, excluding contact of the coolant with atmospheric air. The tank got its name due to the presence of a membrane that divides it into two parts, one of which is intended for the coolant, and the second is filled with nitrogen, the pressure of which equalizes the pressure of the heating system.
Basic principles of work
The heating system of a closed type consists of the following elements:
- heating boiler
- Membrane Type Expansion Tank
- circulation pump
- Security groups
- pressure gauge
- Relief valve
- heating appliances
When the heating system is started, a pressure is set in the expansion tank equal to the static pressure of the entire heating system. When heated, the coolant increases in volume and creates excess pressure in the system, which opens the valve in the expansion tank and pushes part of the liquid into it, which leads to equalization of the pressure level in the system as a whole and in the expansion tank in particular. The liquid goes back thanks to the circulation pump.
It should be noted that in a closed type heating system there is no possibility to discharge "excess" liquid into the atmosphere, as it happens in open gravity systems. In the event of overheating or an excessive increase in the volume of the coolant, the pressure in the system may exceed the critical value (usually 2-2.5 atm), which may cause the system to depressurize and fail.
To avoid emergencies, closed heating systems are necessarily equipped with safety groups and pressure gauges, and the volume of expansion tanks is selected based on at least 60% of the total volume of the heating system, which is not very convenient when heating large areas
Benefits of a closed heating system
Closed heating systems in comparison with open systems have a number of undeniable advantages:
- Coolant movement speed much higher than in an open heating system, due to which the heat transfer of heating devices is higher and the temperature difference between the coolant in the return and supply pipelines is lower (the coolant simply does not have time to cool down). In closed systems, it is 18-22 degrees, which is more acceptable for the boiler. As a result, heating equipment operated in a more gentle mode works longer.
- The speed of movement of the coolant is due only to technical characteristics of the circulation pump and the level of hydraulic resistance of the system, which makes it possible to use pipes of smaller diameter during installation and install heating appliances smaller internal volume. This means that the closed system has less inertia and allows you to adjust the temperature level in the room.
- Can work on any coolant: water or antifreeze, which is especially important for dachas and country houses where there is a high risk of interruptions in the operation of the boiler or heating systems operate intermittently. It should be remembered that antifreeze has greater fluidity and is able to "leave" the system where water does not form a leak. Its choice is possible only if the quality sealing of the system is ensured.
- Closed heating systems are mounted without angles and work even in the presence of small "errors" in the system, which makes their self-installation available.
- Closed systems exclude contact of the coolant with air, due to which there is no oxygen inside the system, and, therefore, there is no corrosion. True, it is not possible to completely eliminate oxygen from the coolant, and the processes of oxidation of equipment and pipes from the inside still go on, but they are insignificant and incomparable with corrosion processes in open heating systems.
- In closed heating systems No air locks
- There is no need for them remove expansion tank outside the heated room and install it in the attic. The tank can be mounted almost anywhere, but it is usually installed on the return line along with the circulation pump. Previously, the choice of location for installation was dictated by the limitation of the temperature level of the liquid pumped by the pump. The heated water was too hot for that. Modern circulation pumps are not so sensitive to the temperature of the coolant and can be installed directly on the supply pipeline. This means that the installation of an expansion tank and a circulation pump on the return line is just a tribute to tradition, and not a necessity.
- Heating systems of closed type suitable for objects of any size and height
Disadvantages of a closed heating system
- The system depends on electrical energy and in the event of an emergency shutdown, it also fails. In this case, it is necessary to provide for a backup power source.
- The system must have a properly mounted security group
- The expansion tank must have a sufficient volume to accommodate at least 30% of the coolant, and preferably 60% of the coolant.
Installation of a closed heating system is carried out in such a way that it is possible to turn off any of its elements without stopping the operation of the remaining part of the system and draining water from it. For this, shut-off valves are used, preferably ball valves. They are installed at the inlet and outlet of heating devices. In this case, a spare (bypass) line is provided. With the help of taps, you can regulate the temperature level in the room and cut off the radiators in case of a leak or if they need to be replaced.
Shut-off valves are also installed before and after the circulation pump and expansion tank.
- security group
- boiler
- shut-off valves
- heating appliances
- circulation pump
- expansion tank
- return line
- innings
Another feature of the installation of a closed heating system is the installation of a safety group, which must be mounted at the outlet of the boiler. The main task of the safety group is to relieve pressure in case of excessive increase.
A security group consists of the following elements:
- pressure gauge designed to control the level of pressure in the system
- safety valve that relieves pressure when it reaches its maximum value
- air vent designed to release air when airing the heating system
Shut-off valves are never installed between the boiler and the safety group!
Any heating system is a boiler in which the coolant is heated, and radiators connected to the boiler by pipes. Depending on whether the coolant is connected to atmospheric air through an expansion tank or not, the systems are usually divided into open and closed.
The second option is now becoming more common due to a number of beneficial advantages. How is a closed heating system equipped, and what are its advantages?
The main advantages of a closed heating system
A closed-type heating system involves forced circulation of the coolant using the installation of a circulation pump. It helps to increase overall energy efficiency: water circulates faster, so the difference between the temperature of the coolant entering the boiler and leaving it will not be too large. This will reduce energy losses for heating and increase the life of the boiler.
A closed home heating system has several more advantages over an open one, which made it the most common:
Another advantage is the ability to supply pipes of a smaller diameter, which will allow the implementation of various design solutions.
However, it also has a few downsides. First of all, it is the dependence on the availability of electricity in the house. When it is turned off, the circulation pump will turn off and the movement of the coolant in the system will stop, which completely paralyzes the heating operation.
To avoid this, parallel options are often mounted in country houses: the pump is installed so that, if necessary, it can be bypassed and start the natural circulation of water in the system due to the pressure difference. In addition, equipment for installing a closed system will cost a little more.
Scheme of the device of a closed heating system
Closed heating systems with forced circulation consist of the following elements:
The scheme of a closed heating system can be expanded with additional elements: instead of heating radiators or in addition to them, underfloor heating can be installed in some rooms, a boiler room can be additionally equipped with a hot water boiler, sometimes equipment for greenhouses and so on has to be included in the home scheme. The final design depends on the specific project of the house and the location of the rooms and additional premises, while it is important that the power of the equipment is sufficient for full heating.
The principle of operation of a closed heating system
In the process of heat exchange, water does not come into contact with the surrounding air and does not evaporate, which is why the system is called closed. How to fill a closed heating system?
Water is supplied to it through a drain pipe: for this, a pump is used and water pipes supplying water from a well or a centralized system. When filling the heating system with coolant, it is necessary to fully open all the taps in order to let the air out as much as possible and prevent the permissible pressure level from being exceeded.
Important installation conditions
Installation of a closed-type heating system requires accurate calculation the amount of coolant, the size of the expansion tank, the pump power and many other parameters. When developing a project, it must be taken into account that the amount of coolant depends on the power of the boiler. Usually, 14 liters of water are required for 1 kW of energy; accordingly, its amount can be calculated for any home.
The volume of the expansion tank should be at least 1/10 of the total amount of coolant, and it is better to choose a tank with a margin. Water has relatively little thermal expansion, and if antifreeze is used as the coolant, it will require a larger tank.
It is installed on the return pipe, like a circulation pump. At the same time, the placement height, unlike an open system, does not matter: air locks from a closed system are removed not through the tank, but through the valves.
Before the circulation pump, it is recommended to install a coarse water filter. A common malfunction is clogging of the impeller with hardness salts, rust and other impurities that can be removed by installing high-quality filters.
Installed before and after the pump Ball Valves, making it possible to stop the water supply to the pump for cleaning or repair. Both the pump, and the expansion tank, and the pressure gauge must be installed in places where they can be easily accessed.
If the heating system has a complex device with several circuits or underfloor heating, it will be necessary to install several collectors and circulation pumps. The more complex the design, the more expensive it will be to purchase materials for its installation.
Properly installing a heating system is not as difficult as it might seem. It is important not to make a mistake in the design work, so it is better to coordinate the finished heating project with specialists. Mistakes in installation are expensive in the future, so it’s better not to spare money for professional advice.
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To date, a closed heating system with forced circulation of the coolant has been successfully used to heat the vast majority of country houses. Its difference from the open circuit is in the movement of pressurized water through a closed network of pipelines in complete isolation from the external environment. If you have not yet decided which type of heating wiring to choose for your home, we recommend that you read this article, which contains all the necessary information about closed-type systems.
Composition and principle of operation
Regardless of the chosen scheme (we will consider their varieties below), it always includes the following main elements:
- heat source - gas, diesel, electric or solid fuel boiler;
- consumers - radiator network and (or) water heated floors;
- circulation pump;
- sealed expansion tank of membrane type;
- safety group, including a device for air release (air vent), safety valve and manometer;
- mesh filter - mud collector;
- pipeline fittings for balancing, emptying and adjustment;
- main and supply pipes.
Note. The heating system can be supplemented with other elements and equipment provided for in the project, for example, a distribution manifold, a buffer tank and various automation tools. A typical two-pipe scheme, the most common in private homes, is shown in the figure above.
The principle of operation of a modern closed system is to transfer thermal energy from the boiler to the radiators with the help of a liquid under excess pressure (from 1 to 2 bar). The expansion of its volume from heating is compensated by stretching the rubber membrane inside the tank, completely isolated from the atmosphere.
Airtight expansion tank device
Airing the heating network is prevented by an automatic air vent installed in the security group. The blast valve located in the same place is triggered in the event of a critical increase in pressure in the pipelines, it is usually set to 3 bar. The mud collector is placed on the return line in front of the entrance to the heat generator and collects the sludge coming from the heating network.
An important point. The circulation pump, forcibly pumping the coolant, can be built into both the return and supply pipelines next to the boiler. Both ways are correct.
Positive aspects and disadvantages
The closed version of the water system has gained popularity due to its numerous advantages:
- no contact with the atmosphere - no loss of coolant due to evaporation;
- antifreeze can be used to fill the network in a periodically heated building;
- there is no need for pipes of large diameters, laid with a significant slope, as is done when installing highways with natural circulation water;
- there is no heat loss through a sealed expansion tank, so the scheme is considered more economical;
- pressurized water heats up much faster, and boils at more high temperature, which reduces the risk of vapor lock formation in case of an emergency;
- the closed system lends itself well to regulation both in individual sections and as a whole.
Note. Tightness gives another important plus - the coolant is not saturated with atmospheric air through an open tank. Air bubbles can only enter the pipelines through make-up from the water supply or through cracks in the tank membrane.
Laying pipelines in the floor and inside the walls
Small pipeline diameters and forced circulation are the most important arguments in favor of modern closed heating networks. All wiring can be hidden in walls or floors, and pipes can be laid with a minimum slope. It serves only to drain water when repairing or flushing radiators and lines.
Now about a fly in the ointment in a barrel of honey. The fact is that the closed heating system of a private house is unable to function autonomously, since it depends on the electricity that feeds the pump. Therefore, with frequent power outages, it is recommended to acquire an uninterruptible power supply or an electric generator so as not to be left without heat.
Reference. On the Internet, you can find alternative options - closed systems, modeled after gravity (gravity). That is, large pipes with significant slopes. But then half of the above advantages are lost, and the cost of installation increases.
The second negative point is the difficulty of removing air pockets in the process of pouring water, pressure testing and starting heating. But this minus will not become a problem if air is removed according to generally accepted technology.
Closed systems diagrams
For heating suburban and country houses The following types of wiring apply:
- Single pipe. All radiators are connected to a single line running around the perimeter of the room or building. Since the hot and cooled coolant move along the same pipe, each subsequent battery receives less heat than the previous one.
- Two-pipe. Here, heated water enters the heating devices through one line, and leaves through the second. The most common and reliable option for any residential buildings.
- Associated (Tikhelman's loop). Same as two-pipe, only chilled water flows in the same direction as hot water, and does not return in the opposite direction (shown in the diagram below).
- Collector or beam. Each battery receives coolant through a separate pipeline connected to a common comb.
Single-pipe horizontal wiring (Leningradka)
Reference. Single pipe systems are horizontal (the so-called Leningradka) and vertical. The latter, where water is distributed to heating devices from risers, are often used in two-story houses.
A single-pipe horizontal scheme justifies itself in one-story houses of a small area (up to 100 m²), where 4-5 radiators provide heating. You should not connect more to one branch, the last batteries will be too cold. The option with vertical risers is suitable for a building of 2-3 floors, but in the process of implementation, almost every room will have to be covered with pipes.
Single-pipe scheme with top wiring and vertical risers
Advice. If your choice fell on a single-pipe closed circuit, it is better to entrust its design and adjustment to specialists. They must make a calculation and select the diameter of the main line so that there is enough heat for all consumers. To learn more practical information, a video from an expert will help you:
The two-pipe circuit with dead ends (shown at the beginning of the article) is quite simple, reliable and unambiguously recommended for use. If you are the owner of a cottage with an area of up to 200 m² with a height of 2 floors, then make the wiring of the mains with pipes with a flow section of DN 15 and 20 (outer diameter - 20 and 25 mm), and for connecting radiators, take DN 10 (outside - 16 mm).
Passing scheme of water movement (Tichelmann's loop)
The Tichelman loop is the most hydraulically balanced, but more difficult to install. Pipelines will have to be laid around the perimeter of the rooms or the whole house and pass under the doors. In fact, a “ride” will cost more than a two-pipe one, and the result will be approximately the same.
The beam system is also simple and reliable, in addition, all wiring is successfully hidden in the floor. The connection of the nearest batteries to the comb is carried out with 16 mm pipes, the distant ones - 20 mm. The diameter of the line from the boiler is 25 mm (DN 20). The disadvantage of this option is the price of the collector unit and the complexity of installation with the laying of highways, when flooring already done.
Scheme with individual connection of batteries to the collector
How to choose equipment
One of important points- selection of a heat source according to the power and type of energy carrier used:
- on natural or liquefied gas;
- on solid fuel - wood, coal, pellets;
- on electricity;
- on liquid fuel - diesel fuel, waste oil.
Reference. If necessary, you can choose a combined multi-fuel installation, for example, on wood and electricity or gas + diesel fuel.
The power of the boiler plant is calculated in a standard way: the heated area of \u200b\u200bthe dwelling is multiplied by 0.1 to convert to kilowatts and by a safety factor of 1.3. That is, for a house of 100 m², a heat source with a capacity of 100 x 0.1 x 1.3 = 13 kW is needed.
For a closed heating system, it does not matter which heat generator you buy, so we will not consider this issue in detail. But you will greatly facilitate your task if you purchase a wall-mounted gas boiler equipped with its own circulation pump and expansion tank, as shown in the photo. For a small house, it remains only to pick up pipes and heating appliances, which will be discussed later.
Varieties of pipes
The heating network of a private house can be mounted from the following pipes:
- PPR (polypropylene);
- cross-linked polyethylene - PEX, PE-RT;
- metal-plastic;
- metal options: copper, steel and corrugated stainless steel.
For self-assembly with low financial costs, it is better to take polymer pipes. To assemble crimp connections made of metal-plastic and polyethylene, special tools are not required, and polypropylene will have to be soldered (the welding machine is rented). Of course, PPR material has no equal in terms of cost, but for reasons of reliability and durability, we recommend using PEX pipelines made of cross-linked polyethylene.
Copper and corrugated stainless steel can also be mounted on compression fittings, but the first has a high price, and the second - a significant hydraulic resistance. As for ferrous metal, it is inconvenient in all respects - welding installation and susceptibility to corrosion push it to the last place. More information about the choice of pipes is described in the next video:
Which radiators are better
Now the distribution network offers heating devices of the following types:
- steel panel;
- made of an alloy of aluminum with silicon (silumin);
- the same, but with a frame of steel pipes, name - bimetallic;
- cast-iron batteries - analogues of the Soviet "accordions" MS 140 and retro-style models.
Note. The last 3 types of radiators are recruited from the required number of heat transfer sections.
Steel panel radiator
From the point of view of economy, it is more profitable to buy steel batteries, which are distinguished by a democratic price. Aluminum appliances are more expensive, but they give off heat more intensively. These 2 varieties are most in demand for closed heating systems of private houses.
Aluminum heater
Bimetallic radiators are designed for heating networks with low-quality coolant supplied with pressure drops, which is typical for district heating in apartment buildings. Buy these expensive items Vacation home With autonomous heating meaningless.
Cast iron "accordions" are much inferior to other batteries in terms of appearance and weight. But due to the low price, they are used in industrial buildings and outbuildings. At the same time, vintage cast iron radiators have an impeccable design, but are too expensive for the price.
To select a heater by power, make a simple calculation: divide the heat transfer indicated in the passport by 1.5. That's how you'll know real power radiator, because the documentation reflects the characteristics for certain conditions exploitation that do not correspond to reality.
Advice. Do not forget to purchase radiator fittings - a ball valve for supply and a balancing valve for the return. If you decide to put energy-saving thermostats with presetting on the batteries, then a conventional shut-off valve should be installed at the outlet of the device.
Pump and expansion tank
In closed heating systems of private dwellings, 3 types of household circulation pumps are usually used, developing a head of 4, 6 and 8 m of water column (this pressure is 0.4, 0.6 and 0.8 Bar, respectively). We suggest not to delve into complex hydraulic calculations, and choose a pumping unit according to the following criteria:
- For a one- and two-storey building with an area of up to 200 m², a head of 4 m is sufficient.
- A cottage with an area of 200-300 m² will need a pump with a pressure of 0.6 bar (6 m).
- The circulation in the network of a three-story mansion of 400-500 m² will be provided by a unit with a head of 8 m of water column.
Reference. The power of the pump must be judged by its marking. For example, a Grundfos 25-40 brand product has a connection diameter of 25 mm and develops a pressure of 0.4 bar.
To select the size of the expansion tank, you should calculate the volume of water in the entire closed heating system, including the boiler tank. Given the fact that when heated from 10 to 90 ° C, water expands by about 5%, the capacity of the tank should be 1/10 of the total amount of coolant.
How to fill heating pipelines
We decided to highlight this issue, since the filling of a closed system must be carried out according to a certain algorithm so that there are no air pockets left:
- First, all heating devices must be cut off from the mains with the help of taps. Open the rest of the fittings completely and turn on the make-up from the water supply. Fill the pipes slowly to allow air to escape through the valve on the safety group.
- When the pressure reaches 1 bar (watch the pressure gauge), stop filling and turn on the circulation pump for a few minutes to squeeze out the remaining air.
- Leave the assistant to maintain the pressure at 1 bar, and you yourself open the radiator valves one by one and bleed the air with Mayevsky taps.
- Upon completion, start the boiler and pump, warm up the coolant and bleed the air from the batteries again.
After making sure that all pipelines and heating devices are fully warmed up, raise the pressure in the network to 1.5-2 bar at a boiler temperature of 80 °C.
Conclusion
Despite the popularity of closed-type water systems, they are not a panacea at all. In many settlements with unstable power supply, it makes no sense to install such circuits, because you will have to bear the cost of buying a UPS or a generator, and this is not practical. In this situation, there is no alternative to gravity systems with natural circulation.