Closed heating system: forced circulation scheme. Expansion tank for closed type heating: installation Wiring diagram for a closed heating system

Even a minor repair of one of the radiators or a heating pipe is inevitably associated with a complete drain of the coolant from the heating system. After completion of work, the circuit will have to be filled with water. The question arises - how to start the heating correctly? What temperature should the water be, at what speed should the liquid be poured? How to prepare and flush the home heating network? It is better if the work is done by the masters - many factors will have to be taken into account.

Types of heating systems in private houses

Residents apartment buildings It is not necessary to engage in an independent start-up of the heating system. Before starting repairs, specialists will warn all neighbors about the work and drain the liquid from the whole riser. The filling will also be handled by services that serve communications.

In a private house, heating can be installed in accordance with one of 2 standard schemes:

1. open.

1. closed.

An open network, which is also called a gravity network, is built without the installation of circulation pumps that distill the coolant inside the network. The fluid circulation is carried out by natural processes: hot water rises up, where in the expansion tank installed at the highest point, the medium comes into contact with air. The cooled water descends to the lower part of the circuit, to the boiler, and is supplied for heating.

Open systems are rarely mounted. You can meet the "classics" only in houses where old boilers, metal pipes and cast-iron radiators are used for heating. The volume of coolant in these types of heating networks is large, respectively, the energy consumption is not economical.

Closed circuits are heating with the connection of pumping equipment, which provides constant circulation hot water inside the system. Energy consumption (gas or electricity) is minimal, because the volume of liquid is only a few tens of liters. Due to the constant movement of water, the boiler is turned on only to heat the coolant to a predetermined temperature.

Replacing the coolant: reasons and frequency

Replacing water in a closed and open heating circuit is carried out:

• During the first start of heating.

• After seasonal drying.

• When starting after repair work.

Regular topping up of liquid is required during operation, if there was no drain after the heating season.

Why drain water from a home system

The question to which there is no definite answer is whether it is necessary to drain the circuit annually after the end of the heating season? The decision depends on the type, age and material of manufacture of the main elements - pipes and radiators, as well as on the total volume of liquid.

Most often drained for the summer systems with old cast iron radiators. The reason is the appearance of a leak after turning off the boilers. Old cast iron fins are screwed together with old gaskets. When there is hot water inside the batteries, the seals expand to provide a stable seal at the seams.

After the water cools, the material from which the gaskets are made naturally shrinks, and at the junction of the ribs, a leak begins. But a long downtime of old radiators without water is fraught with accelerated corrosion, rust inside the radiator and old pipes crumbles in a dry environment, and can disable the entire riser.

In closed new circuits, filling the heating system is not a costly process. But it is not recommended to completely drain the liquid every year - this is not necessary.

The frequency of replacing and topping up fluid in the heating system

How often do you need to change the fluid in the heating system? A few general rules:

• In contours open type In private homes, it is enough to simply add water if the system is tight, without subjecting old communications to stressful checks in the form of long dry downtime. Replacement is necessary only in case of emergency repair or preventive sealing, after flushing.

• Closed heating systems need preventive flushing and change of coolant after a few years.

The frequency of filling with new fluid depends on the characteristics of the water, the life of the synthetic coolant, general condition systems. With strong airing of the extreme points, it is recommended to identify the cause - find the place of the leak and check the tightness of the heating network. Typically, water changes are carried out every few seasons.

The choice of coolant: what to fill in the home system

Before pouring new fluid into a closed-type heating system, it is imperative to select a coolant. Only 3 options:

1. Water.

1. Distilled water.

1. Synthetic carrier.

Important! Water can be used in any home heating system, as long as part of the circuit does not come into contact with cold outside air. If the boiler room is outside the house, the pipes are laid in the ground without thermal insulation, it is necessary to use non-freezing liquids - when the boiler is turned off, frozen water will lead to cracking of the pipes.

Can the system be filled with tap water

Do not try to save money by pouring tap water into the new system. Tap water is “enriched” not only with chlorine, which, when heated, adversely affects the surfaces it comes into contact with. Under the influence of temperature, which can reach 60 - 80 °, plaque begins to form on the inner walls of pipes, connectors, radiators. The deposits resemble scale inside an electric kettle with the same consequences: hard deposits eventually block the internal gaps. As a result, some of the radiators can remain cold even at high media temperatures.

In addition to troubles with water stone, which forms a layer of plaque on the walls of pipes, the use of ordinary tap water can provoke problems that arise due to chemical reactions occurring in the carrier during heating. Aggressive impurities do not have the best effect on the state of the coating inside the radiators, corrode seals, and accelerate corrosion processes.

Conclusion - with a small amount of liquid, it makes no sense to save. It is better to pour distilled water into a closed-type heating system.

Advantages:

• Low cost.

• Reduced viscosity, good fluidity.

• No impurities.

• No chlorine.

• Increased boiling point.

Distillate as a coolant has a beneficial effect on the operation of the entire system: purified water warms up faster, the load on pumping equipment is reduced, there is no risk of clogging inside pipes, deposits on the inner walls.

Synthetic coolants: application features

On sale there are ready-made solutions and concentrates based on:

• propylene glycol.

• Ethylene glycol.

• Glycerin.

Despite the imperfect performance of ethylene glycol, it is better not to pour solutions based on it into the home heating network - the substance is dangerous to health.

When buying, you should focus not on the price, but on the degree of concentration of the active substance. Different brands of coolant are diluted in a certain proportion. Before preparing the solution, be sure to read the instructions for diluting the composition.

Synthetic carriers degrade over time, so before throwing away the canister from the concentrate, find information on the expiration date and mark with a marker near the boiler or inlet pipe so that you do not forget to replace the coolant in time.

Replacing the coolant in a standard closed home heating network

The launch of the heating system in a private house with filling with water is carried out using a complex technology. To work, you will have to buy or borrow special equipment and follow the instructions. If you are not sure of the integrity of the circuit, there are visible damage to the elements, be sure to call a specialist.

Preparatory stage: what is required for work

Before filling the heating system in a private house, determine the method of pouring liquid into the circuit. There are 4 options for resolving the issue:

1. Networks equipped with valve automation are filled without third-party intervention. The principle is that when the pressure level inside the circuit drops, the valve automatically opens and filling takes place until the optimum operating pressure is reached.

1. Heating with a modern double-circuit boiler is filled from water pipe: systems are connected.

1. Circuit with expansion membrane tank it is easier to pour through the pipes where the expander is located, after dismantling the tank.

1. With the help of a special supercharger - a pump for pumping water into the heating system, which is connected to the inlet pipe.

From the tools you will need keys of the appropriate diameter for dismantling the tank, a pump if you plan to fill the distillate, a sealing tape for connections.
If the question is being resolved how to start heating in a private house after downtime, or if it is necessary to replace the old carrier, you will have to purchase a special flushing agent.

Leak test: how to make a pressure test

The old network must be checked for tightness and no leaks. Also, a mandatory check is carried out at the first start-up of heating. Do not neglect the crimping stage, especially if the house has areas with floor heating that will be under the screed and decorative coating. Fixing a leak after the repair is completed is expensive and not easy.

Before starting the test of the old heating, all the water is drained. To drain the carrier, open the valve. You need to act slowly and carefully. Before draining, be sure to check the temperature of the water - the media must cool to 30 o. The drain valve is located at the lowest point of the circuit.

Important! Use a measuring container when draining the coolant to find out the exact volume of liquid. There will be no question about the amount of water that needs to be poured into the heating network.

After drying, the air valve is opened - the Mayevsky tap. Air will fill the circuit and equalize the pressure within the system.

Start pressing. Using a pump: connect a hose to the inlet pipe. The valve at the top is left open so that air can escape freely.

The fluid is injected until a pressure exceeding the working indicator by 1.5 times is reached. That is, if the operating pressure is 1.5 bar, when checking, it is necessary to increase the indicator to 2.0 - 2.25 bar (but not more than the maximum indicator allowed for the boiler).

Close the top valve after water begins to flow from it. Assess tightness. Check the dryness of all difficult areas:

• Places of entry and exit of pipes from radiators.

• Pipe connections.

• Points at the inlet and outlet of the boiler.

• Other threaded connections.

The liquid under high pressure is left for several hours: if during this time there is no leak, then the heating is in order.

There are two ways to create excessive pressure: liquid (water injection) and dry (air injection). Complexity self check is that when pouring water, an unpleasant situation may arise if there is a gap in the circuit (crack or leaky connection). It is better to entrust the crimping to the master.

Do you plan to leave water as a heat carrier? Simply drain off the excess until the pressure drops to an operating value of 1.5 bar.

Flushing your home heating system

Cleaning must be done:

• If the system is old.

• If ordinary water was used as a coolant.

Before washing, dilute the cleaning agent with water in the proportion indicated in the instructions. Pour the product with a pump, fill the circuit with water.

Leave for several hours. During this time, the solution dissolves the sediment accumulated in the radiators, removes deposits from the inner walls.

After flushing, drain all the liquid and proceed to fill the system. Also, flushing is mandatory before filling a closed-type heating system with antifreeze.

Filling with coolant: step by step

Before starting to fill the liquid, measure the required amount of coolant. If synthetic solutions are used, prepare the mixture by diluting the concentrate with distillate to the desired volume.
Before connecting the pump for pumping coolant into the heating system:

• Close the drain cock.

• Check the air bleed valves: all taps must be closed.

• Mayevsky's crane, located at the top point, is left open.

A pump is connected to the pipe through which the liquid will be poured. Typically, pumps are equipped with flexible hoses with threaded connection. The water intake hose is lowered into the container with the carrier.

Start filling the system. It is important to choose the optimal power of the pump, avoiding too fast filling. Simultaneously with the set of water, monitor the open tap. Filling is stopped after the carrier begins to flow out of the open Mayevsky tap.

Checking and preparing for launch

The last step before starting the heating is to remove excess air and check. It is necessary to bleed the air remaining in the circuit from all air valves. To do this, alternately open the taps at the extreme points, release air. The taps are closed after the water starts to flow.

When all the air is bled, check the pressure indicator. Normally, the indicators of all pressure gauges installed in the circuit should match, and be at around 1.5 - 1.8 bar. When using antifreeze, the indicator is sometimes increased to a maximum of 2 bar.

After checking the pressure, turn on the boiler. At a carrier temperature not exceeding 40 °, the system operates up to 1 hour. Then the heating is turned off. After cooling, another check is performed at a higher temperature. The carrier is heated to 60 - 70 o. In this mode, heating is left for 2 - 3 hours.

Starting an open heating system

Filling an open heating system is easier. No special tools needed. It is enough to determine the upper point of finding water in the expansion tank. You will need an assistant who will monitor the air taps.

Work rules

The liquid is drained through the drain pipe located at the lowest point. If necessary, the circuit is flushed. Filling the system is performed in the following sequence:

• Shut off the drain valve.

• Open the air bleed valves.

• Distillate is slowly poured into the expansion tank.

Continue to fill the system with short breaks so that the air rises evenly to the surface. Filling is carried out until the moment when liquid begins to flow from the air taps. The valves are closed.

Add water to the expansion tank up to the mark. You can not fill the expander completely. When heated, the volume of liquid increases, and water over the edges of the tank will begin to pour out. The maximum coolant level is 2/3 of the internal volume of the tank.

System check and maintenance

After completion of work, air is bled from the radiators. Check each valve one by one. Add the required amount of water to the tank.

When operating an open system, it must be remembered that the warm carrier is constantly in contact with air, and, accordingly, evaporates. Therefore, periodically it is worth looking into the expansion tank. When the level drops, simply top up with enough water.

Before checking, be sure to turn off the boiler and wait until the water has cooled to room temperature. Do not add media to hot water. Use liquid with a temperature up to 40 o.

teploguru.ru

Main characteristics

Closed-type heating systems have their own characteristics:

1. The coolant is hermetically sealed and does not come into contact with air.
2. To maintain pressure inside the system, special expansion tanks are used that support this indicator.
3. The coolant practically does not evaporate, which does not require its constant renewal.

Such systems also require the presence of a circulation pump, which mixes the liquid in the pipes.

There are several options for filling a closed heating system with liquid:

• For filling, you will need a pump that will supply water directly from a well or other source. We connect the discharge hose of the device to the drain pipe, on which you must first open the shut-off valve. It should be said that when performing such work, it is necessary to open all the shut-off and Mayevsky valves (for air outlet) to allow water to enter any point of the system.
• Expansion tanks in such mechanisms are mainly mounted to the pipe with a thread, which makes it very easy to remove them. Thus, you will have access to the pipe. Using this hole, you can pour water into this system. Very often, expansion tanks are installed at the highest point, which makes the procedure even more convenient. When water is visible from the pipe, you can finish filling and mount the expansion tank in place.

To create pressure in the system after that, you can remove the nipple, which is located at the top of the tank, and pump it to the required level with a conventional pump.

It is very important to constantly monitor the pressure gauge so as not to exceed the pressure level in the system and not provoke an accident. As you can see, pumping water into such structures is relatively simple, but it is very important to follow the sequence.

How to pour the coolant into the heating system with your own hands, see the video:

stroybud.com

How to distinguish a closed heating system from an open one

The process of filling heating with water largely depends on its design:

• Open. This system uses the natural circulation of the coolant (usually water), when there is no additional pressure. The basis of its work is the elementary laws of thermodynamics: the liquid circulates here slowly, because additional pump not used. At the highest point of the open circuit, a special expansion tank is mounted to compensate for the increase in water volume when heated. This container takes in excess water during expansion, returning it back in a cooled state. The tank is not airtight, so the liquid constantly evaporates from it: its volume has to be replenished from time to time. The boiler in an open system, as opposed to the tank, should be mounted at the very bottom of the diagram.

• Closed. A completely sealed system in which the heated coolant moves under the influence of a circulation pump. Closed-type heating is also equipped with an expansion tank, however, unlike an open system, it is completely sealed here and can be installed anywhere in the system, and not just from above. Inside the container there are two compartments separated by a rubber membrane. The lower part of the expansion tank is filled with liquid, and the upper part is filled with air: due to its pressure on the membrane, a comfortable pressure level (1.5 atm.) is maintained in the circuit. When the temperature of the coolant rises, it penetrates through the valve into the expansion tank and compresses the air. After cooling, the liquid is pushed back into the circuit by compressed gas.

The list of situations when there is a need to fill the heating system with water:

1. On first start. As already mentioned, this procedure is usually carried out by those plumbers who were involved in the installation of the heating system.

1. Repair. The preliminary discharge of the coolant is accompanied by repair measures when it is necessary to repair or replace the shut-off valves, radiator, pipeline section, etc.

1. After seasonal reset. Systems with cast-iron radiators are tried to be emptied after the end of the heating season, as this reduces the wear of intersectional paronite gaskets by an order of magnitude. In addition, in some cases, the coolant can be drained for the winter: this usually happens in country houses which are not used in winter.

1. Reducing the quality of the coolant. The fluid inside the system is constantly exposed to critical influences, either heating up or cooling down. This provokes precipitation (if water is used) in the form of lime and rust. For synthetic coolants, such an operating mode is fraught with the fact that the viscosity level changes. You should also take into account the fact that in metal circuits, the liquid gradually accumulates iron impurities in itself. All this leads to a decrease in the efficiency of heating and its operational resource, up to the failure of individual elements. Therefore, there are certain recommendations on the frequency of replacement of the coolant, depending on the situation. For example, it is recommended to change distilled water in a system with a double-circuit boiler once a year, before the start of a new heating season.

Preparation

Regardless of whether a new, just installed system is being launched, or the circuit was reset to repair or replace the coolant, the engineering network must undergo certain preparation before filling:

• Drain. Before pouring a new coolant into the system, the old one must be completely drained. To do this, turn off the boiler and wait for the water temperature to drop to room temperature. Further, by opening the drain valve at the bottom heating circuit, drain all the liquid: it must be collected in special containers for subsequent disposal. After waiting for the system to be completely empty, open the Mayevsky valve at its upper point - this will allow the pressure in the pipes to stabilize.

• Flushing. It is necessary in order to remove all debris from inside the circuit - chips, scale, limescale and so on. This is done using a pump connected to the network, which pumps the flushing solution inside. It often takes several cycles until the water comes out completely clean. The water for the last wash is enriched with neutralizers to remove additives in the first portions.

• Pressing. It allows you to test before pouring the coolant how tight all the joints and connections of the system are. For this, excess pressure is created inside the circuit by forcing air or using a coolant. To carry out the test, you will need a mechanical (electric) pump. There is also an option to connect the water supply, but this kind of procedure is much more difficult. Before switching the pump to the inlet pipe of the system, all joints and connecting nodes must be carefully inspected. If no defects were found, excess pressure is created inside the circuit (it is necessary to exceed the norm by 1.5 times).

• Elimination of leaks. All leaks found during pressing must be eliminated. If the flaw is at the junction, then it is repacked by installing a new seal. Leaks in the middle of the pipe are solved by replacing the damaged section.

• Checking the set. closed system before filling with water must be checked for the presence of the necessary protective equipment. First of all, we are talking about Mayevsky cranes, bypasses, thermometers and pressure gauges. If any of these elements is missing, it will most likely cause problems in the heating operation.

Calculation of the volume of coolant

In cases where water is used as a coolant not from the pipeline, it is important to know exactly how much liquid is needed.

You can determine this in the following ways:

1. When resetting the system, measure the drained liquid using a meter or a special container of known volume. The same method can be applied during flushing and pressing the circuit.

1. Separately summarize the volume of the elements included in the system. The parameters of the boiler, batteries and expansion tank are indicated in the passport documentation for these products, and the volume of the pipeline is determined using special tables from the plumbing guide.

Filling a closed heating system

Having prepared the required amount of coolant, you can start filling the pre-washed and tested system. The easiest way to do this is with vibration pump.

Given the particular importance of this procedure, accuracy will be required during its implementation:

1. For the last time, all joints are checked for defects and leaks.

1. Shut-off valves are blocked through which the coolant is discharged from the heating circuit. This is done to avoid unnecessary fluid loss.

1. Check if the air valves are working. If it turns out that their level of performance is insufficient, it is recommended to fully open the Mayevsky valve for the duration of the entire filling procedure. You can also leave the valve in the open position in the upper section of the network, which will significantly speed up the release of air accumulated in the pipes.

1. They begin to pour water through the nozzles adjacent to the boiler. In this case, it is desirable to supply the liquid as slowly as possible: in this case, the internal air can be freely discharged through the open fittings. Rushing at this stage usually results in traffic jams. To avoid water hammer, the tap on the pipe through which water is supplied must be opened no more than half.

1. In the course of filling the circuit, all taps and valves from which liquid begins to splash are closed: before starting the process, it is advisable to place an empty basin or bucket near each of them. For this reason, water is harvested with a certain margin, taking into account possible losses.

1. When pouring water, it is recommended to change the position of the pump from time to time, switching to higher outlets. This is especially true for filling a closed system in houses with several floors.

1. Checking the quality of the filling. To fill the amount of coolant, it is recommended to determine not only the total figure, but also the volume of individual sections of the circuit. This will make it possible to control the quality of filling during its implementation using counters on the inlet nozzles. This will allow you to monitor the amount of already pumped coolant, comparing it with the volume of individual elements of the system. If, after filling a certain area, it turns out that it took less liquid than was calculated, then an air lock has formed inside. If the filled volume of the coolant exceeds the calculated data, you need to look for a leak.

1. Release of excess air. Upon completion of the filling procedure of a closed system, it is necessary to remove all air from it. main pipe deaerate using an air valve, which is usually on the boiler. If the forced circulation method of the coolant is used in the circuit, then air is bled from the pumping equipment using an air valve, which is usually located in front of the device.

Each radiator must also be freed from air pockets, starting with the heating elements on the ground floor. This procedure is very simple: with the help of a key or a screwdriver, the Mayevsky tap is opened, closing it only after water appears in the hole. In conclusion, you need to check the return line using the valves installed on it. Having released all the air, the pressure in the closed system must be increased to 1.5 atm., And only after that, turn off the water supply.

Feeding the system

To provide effective work closed heating circuit, the pressure in it must be kept at a constant level. This is directly affected by the volume of coolant circulating through pipes and batteries. In any case, it will gradually leak out, despite the high level of tightness of the system: to make up for these losses, fluid replenishment will be required. The issue is solved by special make-up valves, which are equipped with sections of the circuit with the lowest pressure (most often - next to the pump, directly in front of it).

Small houses with low power heating systems are usually equipped with mechanical type valves. In such a scheme, compensation for pressure surges occurs due to the rubber membrane of the tank. In order to avoid the occurrence of emergencies, it is necessary to constantly monitor the pressure parameters.

Automatic completion

Double-circuit boilers, as a rule, have a device for automatic filling of the coolant. Install this electronic control unit on the inlet pipe. The convenience of this solution lies in the fully automatic control of the pressure in the system through the timely pumping of fluid.

In the event of a critical underestimation of the pressure in the network, the signal from the pressure gauge is sent to the control unit. He, in turn, activates the supply valve, which begins to let water into the system until the pressure is completely stabilized. However, convenience comes at a price, which is expressed in the high cost of automatic filling devices.

How to pour water into an open heating system

In order to fill the open heating system of a private house with a coolant, a slightly different procedure is used. The main difference from closed networks lies in the internal pressure of the circuit: here it corresponds to atmospheric pressure, which makes it possible to use an expansion tank as the main control device. In open heating systems, it is mounted above all other elements.

Step-by-step instructions for filling an open heating system with water:

1. Draining the old fluid and cleaning the circuit. This is done in the same way as in the case of a closed system.

1. To fill water into an open system, an expansion tank is used, which looks like an open tank. After removing the lid, they begin to pour water: filling a small circuit is usually done with a bucket. Filling large systems in this way is quite tedious, so it is better to use a household vibration pump. This will require a capacious tank with pre-prepared water. The pump is equipped with flexible hoses on clamps: one end is immersed in a container of water, and the other in an expansion tank.

1. It is recommended to supply water slowly so that the air has enough time to escape. When using a vibration pump, it is necessary to ensure that the pressure in the circuit during its filling is within 1.5-2 atm. When it is lowered, more water is added to the preparation tank so that it is possible to immerse the suction hose deeper. The water supply is shut off after it begins to pour into the expansion tank.

1. At the end of the procedure, it is necessary to free the circuit from air pockets. To do this, Mayevsky's taps are opened in turn on all existing radiators, closing them only after the appearance of water. In order not to soak the floor, it is recommended to substitute a portable container under the taps. After releasing the gas from all batteries, top up the water in the tank. As practice shows, the final release of the open system from air occurs through the expander after the first furnace.

During intensive use open heating(most often this happens in winter) the coolant will gradually evaporate through the expansion tank. This is explained by the high temperature of the coolant. To maintain the performance of the system, it must be periodically topped up, making sure that its temperature does not rise above +80 degrees.

What water is better to fill in the heating system

There are several types of water poured into the heating circuit:

• Water supply. This also includes liquid taken from a well, well or nearby reservoir. The main advantage of this option is its cheapness. However, the quality of such a coolant is rather low: it acts quite aggressively on the inner walls of the circuit due to the salts and oxygen dissolved in it.

• Boiled. Boiling allows you to remove from the water part of the oxygen and salts that precipitate. However, it is quite difficult to prepare water for a volumetric circuit in this way.

• Cleaned with reagents. To neutralize harmful impurities, instead of boiling, it is convenient to use special chemical substances- reagents. Water prepared in this way needs to be carefully filtered before being poured into the system.

• Distilled. It is sold in plumbing stores in containers of various sizes. Similar properties also has rainwater, which some owners of private houses specially collect for subsequent use in heating networks.

• Antifreeze. They are used instead of water in cases where the heating system is prone to freezing (the crystallization temperature of antifreeze is much lower than that of water). This method of filling the heating circuit is rarely used because of its high cost.

Conclusion

Filling the heating circuit with water is a rather complicated and time-consuming procedure, which is recommended to be performed by at least two people. During its implementation, it is important not to rush, carefully following all the recommendations. special attention the preparation of water for pouring into the circuit deserves: in cases where, for financial or other reasons, liquid from the water supply is used, it must at least be boiled. To remove sediment and rust particles gradually accumulating in the coolant, it is recommended to equip the system with special mud filters.

5domov.ru

How to fill the heating circuit with water

Due to the fluidity and high heat capacity, heat transfer fluids are used to transfer heat from the boiler to consumers, among which water occupies the first place.

It is used to fill even the most capacious heating systems. It is widely available and inexpensive, which determines the widest scope.

Both pumped out from natural reservoirs or wells, and tap water has many impurities and mineral inclusions. When boiling, the impurities settle like scale on the walls of the boiler and form growths similar in composition on the pipes. These deposits are extremely harmful to systems with the latest modifications of heating units. Therefore, water must first be purified, boiled, or, if funds allow, purchase distillate.

The second drawback of water is the ability to contain oxygen, which causes corrosion of the metal. Due to the high mineralization, coupled with the oxygen released during heating, it is not recommended to change the water in the heating circuits more than once a year.

Weighty advantages of water as a heat carrier are optimal viscosity and heat capacity. It accumulates and gives off heat better than antifreeze by 15-20%. Inferior to them in terms of fluidity, due to which it does not seep through the seals of the detachable joints of the system, in terms of viscosity, due to which it moves faster through the pipes.

Calculation of the volume of coolant for filling

To correctly fill your own heating system with water, you need to determine it will be required in liters. The volume of the coolant without any problems can be calculated by yourself. To do this, we need to sum up

V syst. heating = V boiler + V expansion tank + V radiator + V pipes

The useful volume of the boiler is usually indicated by the manufacturer in the technical documentation for the equipment he produces. The capacity of sectional radiators too. If such information cannot be found, then there are average indicators:

V of one section of the radiator, depending on the material of the case:

The total volume of the radiator is found by multiplying this figure by the number of sections.

V expansion tank of a closed type before purchase is selected so that its useful volume is equal to or slightly exceeds the volume of water, taking into account thermal expansion. So this parameter must also be known.

For open-type heating systems with an expansion tank that freely communicates with the atmosphere, the volume is taken according to the actual dimensions.

Volume in pipes:

V pipes = 0.786×D 2×L

where D is the inner diameter of the pipes, L is the length of the pipes.

The volume of the system will then be:

V system \u003d V pipes + V boiler + V expansion tank + V consumers.

Where V consumers, this is the sum of the volumes, the boiler and other devices. Their volumes can be found in the technical documentation or calculated. It is tedious to increase the calculated volume by 15-20 percent, i.e. multiplying by 1.15 or 1.20.

A more time-consuming way is to fill the system with tap water and then drain, measuring the volume with a meter or measuring containers.

Sometimes tap water is used, but this greatly reduces the heating time. Saving a ruble, we lose thousands. It is better in this case to pass water through special membrane or chemical cationic filters.

To fill the heating, we also need adapter hoses and a pump for pumping liquid.

The dependence of the pouring technique on the cause

The reasons for filling affect the sequence of work. If this is a new system, then we check it visually and carry out tests, pressure testing by pumping in air or liquid about 2-2.5 atmospheres (the norm is 1.25 part of the working pressure, but not less than 2 atmospheres). We check the absence of pressure drop on the pressure gauge.

To fill small heating circuits, you can take a car pump instead of a compressor. Sometimes pressure testing is carried out directly with liquid using a centrifugal pump, after connecting the expansion tank to the system. For small volumes, a hand pump with a liquid compartment can be used.

If we carry out periodic cleaning of the system with the replacement of water, then it is necessary to first drain the liquid, having prepared a place or container for it. After waiting for the coolant to cool, we release excess pressure by unscrewing the nipple. At the top point, we open the valve or Mayevsky valve to communicate with the atmosphere. At the bottom point, gradually open the drain valve. With a sharp opening, water hammer occurs, leading to damage. Here you need to be careful.

After draining the coolant, we fill the system with flushing liquid and use the pump to circulate it.

Then washed clean water with additives and a neutralizer designed to neutralize first flush additives.
After these operations, as in the first case, heating is pressure tested. Identified leaks and weak points are usually in places welding work and threaded connections.

Cast iron batteries are equipped with connecting gaskets, which dry out over time, coarsen and leak when cooled. They should be replaced and additional tightening of the batteries should be carried out. After the repair work, again crimping and with a positive result, we proceed to the next stage.

Heating is filled with water through the lower point with the top open. Having connected the electric pump, we pump water into the system through the tap. Moreover, the valve is half open or less to prevent water hammer. Gradually, the system fills up, which confirms the noise from the movement of water and a slight gurgling. We finish when water starts to flow from the top point.

Then we begin to bleed air from connected consumer appliances, a boiler, boilers, an expansion tank with a membrane and batteries using the available taps and valves. Next, we connect a transparent hose to the upper point of the system, which we lower into a container with a coolant. Turning on the pump, we additionally fill the heating until water flows out of the transparent hose in the container without air bubbles.

If possible, after that, you can loop the pumping system with a hose and drive the coolant several times. This will provide additional degassing. And finally, air is pumped behind the expander membrane, providing the necessary pressure for the operation of the heating circulation pump, which we turn on for a run without heating.

To fully check the quality of filling the system, it is necessary to turn on the heating and heating on a trial basis, determine the absence of air pockets and the uniformity of heating using a thermal imager or an infrared temperature meter.

At the same time, with the help of taps or modern temperature controllers, the installation and regulation of temperatures in the premises is carried out. The effectiveness of thermal insulation is also evaluated. It is necessary to provide a supply of purified water and a means of adding it to the system in order to eliminate evaporation losses. All these actions are designed to ensure trouble-free operation of heating for the winter period.

Heating make-up rules

Recently, not only in private houses, but also in apartments, they began to arrange individual heating. Usually, double-circuit boilers with a make-up module are installed. And it’s easier to learn how to recharge yourself than to call the master, for this:

• We open the tap at the bottom of the boiler, then at the top of the system the air release valve and when water appears, close it and the feed tap.
• We turn on the boiler and if murmuring and gurgling are heard in the pump, then we remove it from the boiler outer skin and we find it.
• We loosen, but do not unscrew the screws with a screwdriver, to bleed air from it until moisture appears. The pump has a cover screwed on for this. Although the instructions say that these boilers have automatic air venting devices, they cannot remove all of it.

Especially at the first start-up of heating, it is necessary to gradually, smoothly heat up the coolant to avoid damage from water hammer. You can not immediately turn on the boiler for full power. When heating is stopped, it is also important to lower the temperature slowly.

This is especially important for extended heating networks, which have significant deformation and thermal expansion. From this expansion or contraction, the retaining fasteners or molds generate stresses that are discharged abruptly, transferring the impact of the liquid.

Fluid, depending on flow sections, can increase the force of impact and produce destruction elsewhere, usually at bends. And if resonance occurs, then the loads increase many times and the pipes even break off the mounts. They begin to "play" and "dance."

With rapid filling with liquids, in pipes, due to air pockets, pressure increases are also formed, which are discharged by water hammers. This is where the recommendation to drain and fill the heating comes from slowly, opening the tap a quarter or half. Resonance phenomena, depending on size, weight, fastenings, deposit thickness and other factors, vary. This imposes additional restrictions. You need to take your time and be careful.

That is why the design of heating networks of enterprises and apartment buildings is done by specialists taking into account many factors. Heating of individual houses is done according to standard projects.

Technological progress and cheaper smart home equipment allows using a smartphone to control and change heating parameters remotely. The main thing is to be in the zone of action cellular communication and the Internet. This further expands the possibilities of using water, because timely measures can be taken to prevent its defrosting.

Other amenities, such as raising the room temperature before arrival and economy mode during departure, are included.

The choice of water for heating is advisable if a backup heating system is provided. If heating in winter is used periodically or there is a possibility of shutdown and defrosting of the equipment, then it is better to use antifreeze liquids. For example, in a dacha with short-term visits characteristic of dacha winter life.

Refueling with non-freezing coolant

Before figuring out how to complete various systems heating with non-freezing liquids or antifreeze, you should understand their varieties.

For normal operation of heating systems, antifreezes (anti - against, freeze - freeze) must be:

1. non-toxic, excluding the possibility of the slightest threat to people;
2. non-flammable, and their vapors are explosion-proof;
3. inert to the materials from which the heating system is made;
4. have a heat capacity not less than its calculated value;
5. be fluid.

In its "pure" form, antifreezes are aggressive, capable of destroying pipelines, boilers and heating appliances. To reduce or completely eliminate the negative properties of non-freezing liquids, they are diluted with water in the proportions indicated by the manufacturer of the compositions.

Additives are also used: anti-corrosion, stabilizing, cleaning, anti-foaming and others. The less water, the lower the freezing point and the higher the cost. When diluting antifreezes, it is usually necessary to add the additives that come with the kit. Additives work at a certain concentration.

Without a complex of additives, the compositions cannot be used, since they provide the specified parameters. For the same reason, it is not recommended to mix different coolants, especially with different bases. Their service life is drastically reduced.
Antifreezes have an increased viscosity, they cannot be used in heating with natural circulation.

The average shelf life of organic coolants is 3-5 years, after which the additives lose their properties and the liquid becomes aggressive. When replacing, the old antifreeze must be pumped out and taken for recycling, which further increases costs.

Once upon a time, cars used water for cooling, but now this is a rarity. Now in the world more than 70 percent of heating systems work on water, but the percentage is decreasing all the time. The reason for the widespread use of antifreezes is both their high cost and increased requirements for equipment, toxicity and the need for their disposal. The spent antifreezes, for more complete removal, are drained in a state heated to 45 degrees.

Now the main equipment is designed for water and manufacturers who value their reputation often indicate that they do not guarantee operation on antifreeze. Or indicate the permitted type of antifreeze under certain conditions. It's dangerous to experiment on your own.

Anti-freeze compositions are critical to overheating. They begin to decompose and form gases, solid deposits. Air locks, burns in boilers and equipment failure are formed. At temperatures of 80 degrees and above, vaporization begins, so modern boilers have heating up to 75 degrees, supported by automation. When exceeded, an emergency shutdown of the boiler occurs. With organic coolants, the temperature is reduced to 70 degrees.

For safe work the heating circuit with antifreeze needs automation that turns off the heating unit when the temperature is exceeded. If there is no such device in the heating system circuit, antifreeze should not be used as a coolant.

Usually, the type of coolant is indicated in the technical documentation for boilers and equipment. The use of another coolant removes responsibility from the manufacturer and terminates its warranty service.

For refueling heating systems, coolants based on ethylene glycol, propylene glycol and glycerin are produced.

cheapest ethylene glycol

The disadvantage is toxicity, a dose of 100 - 250 grams is fatal to humans. It has the third hazard class according to GOST. Vapors are also toxic. Permissible MPC norm - 5 milligrams / cu. meter. Therefore, it cannot be used in open heating systems. It is also forbidden for double-circuit boilers, because the product may leak into the hot water supply line.

To exclude this, craftsmen make the water supply pressure higher than heating. But even this does not give a full guarantee and, in case of damage, may cause the boiler to fail. The use of ethylene glycol is only permitted for closed heating systems.

Heating leaks and breaks are very likely. If the system is filled with an inexpensive but toxic ethylene glycol cleaner, leaks can pose a health hazard to homeowners. The relatively low price is the reason for the application. You can't buy health like antifreeze. Therefore, the choice is yours.

Ethylene glycol has 1.5-3 times greater penetrating power and aggressiveness to seals.

Automobile antifreezes, antifreezes, should not be used categorically, as they contain more toxic additives.

For glycol coolants:

1. the maximum temperature should be no more than 70 degrees, which further increases the size of the batteries;
2. viscosity is 40-60% higher and pumping requires 1.5-2 times more motor power and minimization of bends, bends and increased pipe size;
3. volumetric expansion during heating is 140-150% more, it is required by the same amount, an increased volume of the expansion tank;
4. density is 15 - 20% higher, strength characteristics increase.

The construction of a new system designed for the use of synthetic heat carriers, respectively, costs 1.3-1.5 times more expensive than the construction of a water analogue. The considerable cost of the non-freezing liquid itself should not be forgotten either.

Alteration of water is also not used, since the service life is reduced and, as a result, it is more expensive. Glycol mixtures are also aggressive to zinc, causing delamination and sludge that completely clogs pipes. In older structures, galvanized pipes are common.

However, taking into account the above disadvantages, ethylene glycol is still used. It is necessary to fill the systems only after all the equipment of the heating system is adapted for filling with antifreezes.

A special feature is the need to locate the filling equipment on impervious surfaces to prevent glycol from entering the living quarters and carefully control the connections of the adapter hoses. Although this, neat craftsmen, do when refueling with any antifreeze.

The specifics of the use of propylene glycol

Recently, it has been actively replacing other types of heat carriers, although in terms of its physical and technical parameters it almost does not differ from ethylene glycol and requires almost the same change in the equipment of heating systems.
According to GOST, it belongs to the second hazard class and also requires disposal. MPC vapors - 7 milligrams / cu. meter.

The advantages of this non-freezing coolant:

1. relatively environmentally friendly and harmless to humans. This is the main reason why many manufacturers now recommend it for single-circuit and double-circuit boilers;
2. has lubricating properties, which facilitates the operation of pumps;
3. with complete evaporation of water, it does not freeze, while maintaining fluidity;
4. corrosiveness is very low, and with additives it improves even more;
5. If spilled, just rinse with water and wipe.

Polypropylene glycol liquid has disadvantages. This
its cost, which is 1.5 - 2 times higher than ethylene glycol, because it is produced mainly abroad. Fluid is corrosive
To metal pipes, not compatible with pipelines constructed from galvanized pipes, because upon contact with zinc, the additives of the composition lose their properties. At a temperature above the permissible level, decomposition begins with the formation of gases, foam and a solid insoluble precipitate.
Despite all these shortcomings, it is considered one of the best coolants.

Feature of glycerin coolants

As harmless as propylene glycol allowable temperatures. They were historically the earliest to be used for these purposes, getting glycerin from fat. The spill is not dangerous. The advantage is the price, which is lower than that of propylene, while remaining higher than ethylene glycol. Therefore, it is used by counterfeiters to dilute polypropylene glycol.

Even some European manufacturers add it to about 10%, so you need to be careful and read the composition. On the other hand, in the European Union, glycerin is not used as the main component of the coolant.

Glycerin has wider temperature limits up to 105 degrees. Hazard class two.

Flaws:

1. when the maximum temperatures are exceeded during decomposition, a poisonous gas with an unpleasant odor is released;
2. when evaporated, it becomes gel-like, burns and decomposition begin, it is necessary to regularly compensate for evaporation by adding distillate;
3. have increased viscosity and require pipes of larger diameter;
4. easily foams, which is partially removed by additives;
5. has a high penetrating ability and requires the use of paronite and teflon gaskets.

It has significant corrosive activity, and has long been rejected by automakers. Due to modern additives, this is reduced and reduced to nothing. Yes, even with proper use.

Glycerin coolants, however, are recommended to a greater extent than ethylene glycol ones for their harmlessness and, with a complex of additives, work satisfactorily in heating networks. The trouble is that in pursuit of money, they produce products without a full range of additives or without them at all. You need to be careful when buying.

A special type can be attributed to heating systems with electrode boilers, in which the coolant is also a heating element. Heating occurs when current flows through the solution during its ionization.

The solution, in addition to the above, should have a calculated electrical resistivity of the order of 3.5 - 4 kΩ cm. For this, an aqueous solution or a solution of propylene glycol with additives is used, which create the necessary electrical characteristics.

Useful video on the topic

The video will visually present the process of filling the heating circuit and setting up the expansion tank:

Common to all coolants is gradualness when starting the system. The temperature must be increased slowly, in steps, not only because of the coolant, but also additives, which also change their properties with temperature. The process of filling systems with both water and antifreeze is similar, but the requirements for the quality of work and safety when filling with antifreeze are increasing. Antifreezes that have expired require disposable containers and removal for disposal.

sovet-ingenera.com

When a country house is planned to be used not only as a temporary shelter during the velvet season, but also as a full-fledged housing, the heating system becomes an indispensable attribute of your residence. The heating system is thought out in detail and calculated at the stage of the project for the construction (or reconstruction) of the facility - it is designed for many years of operation, and correcting errors will be very expensive in the future.

Closed heating system of a country house.

Statistics show that after all possible heating options have been worked out, the choice most often falls on a closed-type heating system, which is the most common way to provide heat in suburban residential buildings. Unlike an open system, it eliminates the contact of the coolant with atmospheric air, is easily adjustable, and forced circulation allows heating large areas.

Components of a closed system and their purpose

The components of a closed heating system of a private house are:

• source of thermal energy (gas, electric or solid fuel boiler);
• supply, distribution and discharge pipelines;
• pipeline fittings (valves, taps and other fittings).
• heating appliances (radiators, floor heating pipes, etc.);
• circulation pump;
• expansion (compensation) tank;
• security group.

1. The source of thermal energy (boiler) is best chosen with automation. This makes it possible to operate the heating system autonomously according to pre-set parameters, depending on the outside temperature and the level of desired comfort. In this respect . In addition, today they are the most economical. Thanks to the sensitive thermostat, the temperature can be set exactly to the degree - very convenient and economical.

Wall-mounted gas boiler Hermann without a decorative casing.

Electric boilers are not inferior to gas boilers in terms of automation level, but for heating large areas, energy costs will be very significant (about 1 kW per 10 sq. M of heated area), which will significantly affect the family (or personal) budget. Even the most or boilers at existing electricity tariffs cannot be compared with gas counterparts. But if your region is not gasified, and the energy supply is stable and not limited, then an electric boiler is a good solution.

But still, this is a rather troublesome option: their level of automation is minimal, and you still have to harvest and throw firewood (coal, sawdust, etc.) into the furnace manually. But sometimes this is the only way to get heat in our energy-rich country.

How does a closed heating system work?

When the boiler is turned on, the coolant begins to heat up and move along the contour of the heating system under the influence of the centrifugal force created by the circulation pump. With an increase in temperature, the volume of the coolant increases, creating excess pressure. When it reaches a critical value, the safety valve opens, the excess volume of coolant enters the expansion tank, and the pressure drops to the nominal value. After the boiler is turned off (usually this is done by automation at the command of the temperature sensor), the reverse process occurs: part of the coolant from the expansion tank is pushed back into the system by the membrane. This cycle is repeated during the operation of the boiler.

Video

The now widespread open heating system has a number of serious drawbacks. One of them is direct contact with the atmosphere. As a result, a coolant flows through the pipes, in which there is air. Air bubbles can gradually cause corrosion of the metal elements of the heating system, as well as cause the “noise” of the coolant. All this can be avoided by just making a closed heating system of a private house.

The main feature of such systems (and what does not have open circuit) - complete isolation from the influence of the environment. The closed heating system, which you can do with your own hands, includes the following elements:

• boiler;
• automatic air valve;
• thermostatic valve;
• heating radiators;
• expansion tank;
• balancing valve;
• ball valve;
• pump and filter;
• manometer;
• safety valve.

How does closed water heating work? If the temperature of the coolant rises, then excess liquid is squeezed into the expansion tank. When the temperature drops, the liquid returns to the system, i.e. pressure is maintained within a fairly narrow range.

For efficient circulation of the coolant, a pump is used (an open system may have natural circulation). True, there is also a minus here - in the absence of power supply, a closed system will not be able to function normally (lack of electricity for a country private house is a very urgent problem). But the advantages of using a “pump” more than compensate for the disadvantages - for both an apartment and a private house, installation of additional heating systems is possible. In particular, you can make a warm floor.

The circulation pump is installed on the return pipe ("return") in front of the heating boiler. An expansion tank is also mounted here. Such an arrangement of these important elements allows you to be uncritical about the diameter of the pipes used during installation and the observance of the slope, which open water heating must have.

As a result, less time and materials are spent on the installation of such a heating system (for example, it is no longer necessary to insulate the pipeline, since the expansion tank is installed next to the boiler). However, "abuse" similar benefits not worth it. This is especially true for the slope (it’s better to do it anyway) - if it is observed, the system will at least work in the event of a power outage, but it will still work, i.e. defrosting does not threaten her.

In the video below you can see a detailed example of the organization of closed-type heating using solid fuel and electric boilers.

The closed heating system is isolated from air penetration. However, its operation does not provide 100% tightness: air can fill the pipes, for example, when adding a coolant to the system. In this case, it will accumulate at the top points. You can get rid of it by means of a Mayevsky crane or float diverters operating on an "automatic". The air already dissolved in the water is removed using special separators installed directly in the pipeline.

Good results in terms of saving heat gives the use of a thermostat. It turns on the main consumer of electricity (pump) only when the temperature in the room drops below a predetermined limit.

How to choose a boiler for closed heating

The scheme of closed heat supply of a private house provides for the use of any type of fuel. It can be gas (the most efficient and profitable option), electricity, diesel or solid fuel.

It is necessary to pay attention to the power of the boiler. The approximate value for an insulated room with ceilings up to 3 meters high is 1 kW per 10 "squares" of a private house.

The figure above is very, very approximate. It all depends on many factors: the material from which the building is built, the quality of the insulation, the presence (absence) of a heated attic or attic. The efficiency of heating is affected by the number of windows and how well they were installed. Therefore, a competent thermal calculation is required, which a qualified engineer can do.

The heating boiler can be single-circuit, double-circuit or with a boiler. As practice shows, in general country houses have a small area and, consequently, a small need for hot water. From this point of view the best choice there will be a double-circuit boiler (its installation is simple), capable of heating about 10 liters of water to + 30C in half an hour. Boiler with storage boiler more comfortable - it constantly "has" ready-made several tens of liters of hot water - constant filling is not required.

Expansion tank for closed type heating

Most often, in the heating system of a private house, water plays the role of a coolant. As the temperature increases, the volume increases and the pressure increases. If a closed heat supply scheme is used, then the pressure can overcome a certain critical value and then the elements of the heating system will be destroyed.

To avoid such a development of events, the installation of a heating system for a private house involves the use of an expansion tank.

Features of the design of the tank of a closed type

Any tank of this type has two main parts: a body made of metal and an elastic membrane inside.

The scheme of its operation is quite simple - air is pumped into the upper half of the tank (in expensive modifications - inert gas), the lower part is filled with water from the pipeline.

When the coolant is heated, the pressure rises, while the membrane “bends”, condensing air or an inert gas. Safety valves are available to prevent dangerous situations. When the pipeline with water cools down, the air pressure on the membrane becomes stronger than the coolant pressure, and it fills the heating system. The expansion tank is installed next to the heating boiler. Membranes are of 2 types.

• Fixed - tightly fixed around the perimeter of the expander. Such devices can be found in the tanks of the heating system of a private house or a small enterprise.
  

  These membranes will last a long time if you follow the recommendations for use. In the event of a rupture, it is impossible to change such a membrane - you will have to change the entire tank;

• Replaceable - they are made in the form of rubber pears, balls that must be filled with water. The installation of such a membrane is carried out on the tank flange. If a rupture occurs, then you can replace the damaged membrane with a new one with your own hands, without involving specialists.

When planning a heating scheme, it is important to first of all calculate the power of the heating boiler, take into account the number of radiators and the length of the pipeline.

Careful planning and calculation of the water heating system, and the installation carried out in accordance with the obtained data, will help you achieve productive, economical and efficient heating.

In the last few years, a closed heating system has become increasingly popular. Heating equipment is becoming more and more expensive, and you want it to last longer. In systems of a closed type, the possibility of free oxygen getting inside is practically excluded, which prolongs the life of the equipment.

Closed heating system - what is it

As you know, in any heating system of a private house there is an expansion tank. This is a container in which some coolant is removed. This tank is necessary to compensate for thermal expansion in various operating modes. By design, expansion tanks are open and closed, respectively, and heating systems are called open and closed.

In recent years, it has become increasingly popular closed circuit heating. Firstly, it is automated and works without human intervention for a long time. Secondly, any type of coolant can be used in it, including antifreeze (it evaporates from open tanks). Thirdly, the pressure is maintained constant, which makes it possible to use any household appliances. There are a few more advantages that relate to wiring and operation:

• There is no direct contact of the coolant with air, therefore, there is no (or almost no) free oxygen, which is a powerful oxidizing agent. This means that the heating elements will not oxidize, which will increase their service life.
• An expansion tank of a closed type is placed anywhere, usually not far from the boiler (wall-mounted gas boilers come immediately with expansion tanks). An open tank should be in the attic, and these are additional pipes, as well as insulation measures so that heat does not “leak” through the roof.
• In a closed system, there are automatic air vents, so there is no airing.

In general, a closed heating system is considered more convenient. Its main drawback is energy dependence. The movement of the coolant is provided by a circulation pump (forced circulation), and it does not work without electricity. Natural circulation in closed systems can be organized, but it is difficult - flow control is required using the thickness of the pipes. This is a rather complicated calculation, because it is often believed that a closed heating system only works with a pump.

To reduce energy dependence and increase the reliability of heating, they put blocks uninterruptible power supply batteries and/or small generators to provide emergency power.

Components and their purpose

In general, a closed heating system consists of a certain set of elements:

• Boiler with safety group. There are two options here. First - a safety group is built into the boiler (gas wall boilers, pellet and some solid fuel gas generators). The second - there is no safety group in the boiler, then it is installed at the outlet in the supply pipeline.
• Pipes, radiators, convectors.
• Circulation pump. Provides the movement of the coolant. It is installed mainly on the return pipeline (here the temperature is lower and there is less possibility of overheating).
• Expansion tank. Compensates for changes in the volume of the coolant, maintaining a stable pressure.

Now more about each element.

Boiler - which one to choose

Since the closed heating system of a private house can work offline, it makes sense to install a heating boiler with automation. In this case, after setting the parameters, you do not need to return to this. All modes are supported without human intervention.

The most convenient gas boilers in this regard. They have the ability to connect room thermostat. The temperature set on it is maintained with an accuracy of one degree. She fell by a degree, the boiler turned on, heating the house. As soon as the thermostat has tripped (temperature reached), the operation stops. Comfortable, convenient and economical.

In some models, it is possible to connect weather-dependent automation - these are external sensors. According to their testimony, the boiler adjusts the power of the burners. Gas boilers in closed heating systems are good equipment that can provide comfort. The only pity is that gas is not everywhere.

Electric boilers can give a no lesser degree of automation. In addition to traditional units on heating elements, induction and electrode ones appeared not so long ago. They are compact in size and low inertia. Many believe that they are more economical than boilers on heating elements. But even this kind of heating units can not be used everywhere, since power outages in winter are a frequent occurrence in many regions of our country. And to provide electricity to the boiler power. 8-12 kW from the generator is a very difficult task.

Boilers for solid or liquid fuel are more versatile and independent in this regard. An important point: to install a liquid fuel boiler, a separate room is required - this is a requirement of the fire department. Solid fuel boilers can stand in the house, but this is inconvenient, since a lot of debris falls from the fuel during combustion.

Modern solid fuel boilers, although they remain intermittent equipment (they warm up during combustion, cool down when the bookmark burns out), they also have automation that allows you to maintain the set temperature in the system by adjusting the intensity of combustion. Although the degree of automation is not as high as that of gas or electric boilers, it is.

Boilers on pellets are not very common in our camp. In fact, this is also solid fuel, but boilers of this type operate continuously. Pellets are automatically fed into the firebox (until the stock in the burker is finished). At good quality fuel, ash cleaning is required once every few weeks, and all operating parameters are controlled by automation. Only its high price hinders the distribution of this equipment: the manufacturers are mainly European, and their prices are corresponding.

A little about the calculation of boiler power for closed-type heating systems. It is determined according to the general principle: per 10 sq. meters of area with normal insulation take 1 kW of boiler power. Only take "back to back" is not advised. Firstly, there are abnormally cold periods during which you may not have enough rated power. Secondly, work at the power limit leads to rapid wear of the equipment. Therefore, it is desirable to take the boiler power for the system with a margin of 30-50%.

Security group

A safety group is placed on the supply pipeline at the outlet of the boiler. It should control its operation and system parameters. Consisting of pressure gauge, automatic air vent and safety valve.

The manometer makes it possible to control the pressure in the system. According to the recommendations, it should be in the range of 1.5-3 bar (in one-story houses this is 1.5-2 Bar, in two-story - up to 3 Bar). In case of deviation from these parameters, appropriate measures must be taken. If the pressure has dropped below normal, it is necessary to check if there are any leaks, and then add a certain amount of coolant to the system. At elevated pressure, everything is somewhat more complicated: it is necessary to check in what mode the boiler is operating, whether it has overheated the coolant. The operation of the circulation pump, the correct operation of the pressure gauge and the safety valve are also checked. It is he who should dump the excess coolant when the threshold pressure value is exceeded. A pipe / hose is connected to the free branch pipe of the safety valve, which is discharged into the sewer or drainage system. Here it is better to do it in such a way that it is possible to control whether the valve works - with frequent discharge of water, it is necessary to look for the causes and eliminate them.

The third element of the group is an automatic air vent. Through it, the air that has entered the system is removed. Very handy device, which allows you to get rid of the problem of air jams in the system.

Security groups are sold assembled (pictured above), or you can buy all the devices separately and connect them using the same pipes that were used to wire the system.

Expansion tank for closed heating system

The expansion tank for is designed to compensate for changes in the volume of the coolant depending on temperature. In closed heating systems, this is a sealed container, divided by an elastic membrane into two parts. In the upper part there is air or an inert gas (in expensive models). While the coolant temperature is low, the tank remains empty, the membrane is straightened (picture on the right in the figure).

When heated, the coolant increases in volume, its excess rises into the tank, pushing the membrane and compressing the gas pumped into the upper part (in the picture on the left). On the pressure gauge, this is displayed as an increase in pressure and can serve as a signal to reduce the intensity of combustion. Some models have a relief valve that releases excess air/gas when a pressure threshold is reached.

As the coolant cools, the pressure in the upper part of the tank squeezes the coolant out of the tank into the system, the pressure gauge returns to normal. That's the whole principle of operation of the expansion tank of the membrane type. By the way, there are two types of membranes - dish-shaped and pear-shaped. The shape of the membrane does not affect the principle of operation.

Volume calculation

According to generally accepted standards, the volume of the expansion tank should be 10% of the total volume of the coolant. This means that you must calculate how much water will fit in the pipes and radiators of your system (it is in the technical data of the radiators, but the volume of pipes can be calculated). 1/10 of this figure will be the volume of the required expansion tank. But this figure is valid only if the coolant is water. If an antifreeze liquid is used, the tank size is increased by 50% of the calculated volume.

Here is an example of calculating the volume of a membrane tank for a closed heating system:

• the volume of the heating system is 28 liters;
• expansion tank size for a system filled with water 2.8 liters;
• the size of the membrane tank for a system with antifreeze liquid is 2.8 + 0.5 * 2.8 = 4.2 liters.

When buying, choose the nearest larger volume. Do not take less - it is better to have a small supply.

What to look for when buying

The stores have cans of red and of blue color. Red tanks are suitable for heating. Blue ones are structurally the same, only they are intended for cold water And high temperatures do not tolerate.

What else to pay attention to? There are two types of tanks - with a replaceable membrane (they are also called flanged) and with an irreplaceable one. The second option is cheaper, and significantly, but if the membrane is damaged, you will have to buy the whole thing. In flanged models, only the membrane is bought.

Place for installation of expansion tank of membrane type

Usually they put an expansion tank on the return pipe in front of the circulation pump (when viewed in the direction of the coolant). A tee is installed in the pipeline, a small piece of pipe is connected to one of its parts, and an expander is connected to it through the fittings. It is better to place it at some distance from the pump so that pressure drops are not created. An important point is that the piping section of the membrane tank must be straight.

After the tee they put ball valve. It is necessary to be able to remove the tank without draining the heat carrier. It is more convenient to connect the container itself with the help of an American (flare nut). This again facilitates assembly/dismantling.

Please note that some boilers have an expansion tank. If its volume is sufficient, the installation of a second one is not required.

Empty device weighs not so much, but filled with water has a solid mass. Therefore, it is necessary to provide a method of fixing on the wall or additional supports.

Circulation pump

The circulation pump ensures the operability of a closed heating system. Its power depends on many factors: the material and diameter of the pipes, the number and type of radiators, the presence of shut-off and thermostatic valves, the length of the pipes, the operating mode of the equipment, etc. In order not to go into the intricacies of calculating power, the circulation pump can be selected from the table. Choose the nearest higher value according to the heated area or the planned thermal power of the system, in the corresponding line in the first columns find the required characteristics.

In the second column we find the power (how much coolant it is able to pump per hour), in the third - the pressure (system resistance) that it is able to overcome.

When choosing a circulation pump in a store, it is advisable not to save. The entire system depends on its performance. Therefore, it is better not to save and choose a trusted manufacturer. If you decide to buy unknown equipment, you need to somehow check it for noise levels. This indicator is especially critical if the heating unit is installed in a residential area.

Strapping scheme

As mentioned earlier, circulation pumps are installed mainly on the return pipeline. Previously, this requirement was mandatory, today it is only a wish. The materials that are used in the production can withstand temperatures up to 90 ° C, but it's still better not to risk it.

In systems that can also operate with natural circulation, it is necessary to provide during installation the possibility to remove or replace the pump without the need to drain the coolant, as well as to be able to work without a pump. To do this, a bypass is installed - a bypass through which the coolant can flow if necessary. The installation diagram of the circulation pump in this case is in the photo below.

In closed systems with forced circulation a bypass is not needed - it is inoperative without a pump. But two ball valves on both sides and an inlet filter are needed. Ball valves make it possible, if necessary, to remove the device for maintenance, repair or replacement. The dirt filter prevents clogging. Sometimes like additional element reliability, between the filter and the ball valve they put another check valve, which will prevent the movement of the coolant in the opposite direction.

Scheme of connection (piping) of a circulation pump to a closed-type heating system

How to fill a closed heating system

At the lowest point of the system, as a rule, on the return pipeline, an additional tap is installed to supply / drain the system. In the simplest case, this is a tee installed in the pipeline, to which a ball valve is connected through a small section of the pipe.

In this case, when draining the system, it will be necessary to substitute some kind of container or connect a hose. When filling the coolant, a hose is connected to the ball valve hand pump. This simple device can be rented at plumbing stores.

There is a second option - when the coolant is just tap water. In this case, the water supply is connected either to a special boiler inlet (in wall gas boilers), or to a ball valve similarly installed on the return. But in this case, another point is needed to drain the system. IN two-pipe system this may be one of the last in the branch of radiators, to the lower free entrance of which a drain ball valve is installed. Another option is shown in the following diagram. It shows a single-pipe closed-type heating system.

Scheme of a closed single-pipe heating system with a system power supply unit

When planning to create a water heating system in your own home, the owner is faced with a choice of several options. The list of the most important questions includes the type of system (whether it will be open or closed), and what principle the coolant will be transferred through pipes (natural circulation due to the action of gravitational forces, or forced, requiring the installation of a special pump).

Each of the schemes has its own advantages and disadvantages. But still, nowadays, more and more preference is given to a closed system with forced circulation. Such a scheme is more compact, easier and faster to install, and has a number of other operational advantages. One of the main distinctive features - This is a fully sealed expansion tank for heating of a closed type, the installation of which will be discussed in this publication.

But before you purchase an expansion tank and proceed with its installation, you need to at least get a little familiar with its device, the principle of operation, as well as which model will be optimal for a particular heating system.

IN what are the advantages of a closed heating system

Although Recently there have been many modern appliances and space heating systems, the principle of heat transfer through a liquid with a high heat capacity circulating through pipes - without a doubt, remains the most widespread. Water is most often used as a carrier of thermal energy, although in some circumstances other liquids with a low freezing point (antifreeze) must be used.

The heat carrier receives heat from the boiler (furnaces with water circuit) and transfers heat to heating devices (radiators, convectors, "warm floor" circuits) installed in the premises in the required quantity.

How to determine the type and number of heating radiators?

Even the most powerful boiler will not be able to create a comfortable atmosphere in the premises if the parameters of the heat exchange points do not correspond to the conditions of a particular room. As it is right - in a special publication of our portal.

But any liquid has common physical properties. First, when heated, it significantly increases in volume. And secondly, unlike gases, this is an incompressible substance, its thermal expansion must be compensated in some way, providing free volume for this. And at the same time, it is necessary to provide that, as it cools and decreases in volume, air does not enter the pipe circuits from the outside, which will create a “plug” that prevents the normal circulation of the coolant.

It is these functions that the expansion tank performs.

Still not so much in private construction, there was no special alternative - at the highest point of the system, an open expansion tank was installed, which completely coped with the tasks.

1 - heating boiler;

2 - supply riser;

3 - an open expansion tank;

4 - heating radiator;

5 - optional - circulation pump. In this case, a pumping unit with a bypass loop and a valve system is shown. If desired, or if necessary, you can switch forced circulation to natural, and vice versa.

You may be interested in information on how to properly carry out

Prices for circulation pumps

circulation pumps

A closed system is completely isolated from the atmosphere. A certain pressure is maintained in it, and the thermal expansion of the liquid is compensated by the installation of a sealed tank of a special design.

The tank in the diagram is shown pos. 6, embedded in the return pipe (pos. 7).

It would seem - why "to fence the garden"? A conventional open expansion tank, if it fully copes with its functions, seems to be a simpler and more inexpensive solution. It probably costs a little, and besides, with certain skills, it is easy to make it yourself - weld it from steel sheets, use an unnecessary metal container, for example, an old can, etc. Moreover, one can meet examples applications old plastic cans.

Does it make sense to spend money on a sealed expansion tank? It turns out that there is, since a closed heating system has many advantages:

• Complete tightness absolutely excludes the process of evaporation of the coolant. This opens up the possibility of using, in addition to water, special antifreezes. The measure is more than necessary if country house in winter they do not use constantly, but “arrivals”, occasionally.
• In an open heating system, the expansion tank, as already mentioned, must be mounted at the highest point. Very often, an unheated attic becomes such a place. And this entails additional troubles for the thermal insulation of the container, so that even in the most severe frosts the coolant in it does not freeze.

And in a closed system, an expansion tank can be installed in almost any part of it. The most appropriate place for installation is the return pipe directly in front of the boiler inlet - here the parts of the tank will be less exposed to temperature effects from the heated coolant. But this is by no means a dogma, and it can be mounted in such a way that it does not interfere and does not disharmony with its appearance with the interior of the room, if, say, the system uses a wall-mounted boiler installed in the corridor or in the kitchen.

• In an open expansion tank, the coolant is always in contact with the atmosphere. This leads to a constant saturation of the liquid with dissolved air, which is the reason for the activation of corrosion in the pipes of the circuit and in radiators, to increased gas formation during the heating process. Aluminum radiators are especially intolerant of this.
• A closed heating system with forced circulation is less inert - it warms up much faster at start-up, much more sensitive to adjustments. Completely unjustified losses in the area of ​​the open expansion tank are excluded.
• The temperature difference in the supply pipe and in the return pipe in the currents connected to the boiler is less than in an open system. This is important for the safety and durability of heating equipment.
• A closed circuit with forced circulation to create circuits will require tons of smaller diameter pipes - there is a gain both in material costs and in simplifying installation work.
• An open-type expansion tank must be controlled to prevent overflow during filling, and to prevent the liquid level in it from falling below a critical level during operation. Of course, all this can be solved by installing additional devices, for example, float valves, overflow pipes, etc., but these are unnecessary complications. In a closed heating system, such problems do not arise.
• And, finally, such a system is the most versatile, as it is suitable for any type of batteries, it allows you to connect floor heating circuits, convectors, thermal curtains. In addition, if desired, hot heat supply can also be arranged by installing an indirect heating boiler in the system.

Of the serious shortcomings, only one can be mentioned. This — mandatory "safety group", including instrumentation (pressure gauge, thermometer), safety valve and automatic air vent. However, it is rather no no prosperity, but a technological cost that ensures the safe operation of the heating system.

In a word, the advantages of a closed system clearly outweigh, and spending on a special hermetic expansion tank looks quite justified.

How is the expansion tank for closed-type heating arranged and how does it work?

The expansion tank device for a closed-type system is not very complicated:

Usually the whole structure is placed in a steel stamped case (pos. 1) of a cylindrical shape (there are tanks in the form of a “tablet”). For the manufacture of high-quality metal with an anti-corrosion coating is used. Outside the tank is covered with enamel. For heating, products with a red body are used. (There are blue tanks - but these are water batteries for the water supply system. They are not designed for elevated temperatures, and all their parts are subject to increased sanitary and hygienic requirements).

On one side of the tank there is a threaded pipe (pos. 2) for tapping into the heating system. Sometimes fittings are included in the package to facilitate installation work.

On the opposite side there is a nipple valve (pos. 3), which serves to pre-create the necessary pressure in the air chamber.

Inside, the entire cavity of the tank is divided by a membrane (pos. 6) into two chambers. On the side of the branch pipe there is a chamber for the coolant (pos. 4), on the opposite side - air (pos. 5)

The membrane is made of an elastic material with a low diffusion index. It is given a special shape, which provides an "ordered" deformation when the pressure in the chambers changes.

The principle of operation is simple.

• IN home position, when the tank is connected to the system and filled with a coolant, a certain volume of liquid enters the water chamber through the pipe. The pressure in the chambers equalizes, and this closed system takes on a static position.
• With an increase in temperature, the volume of the coolant in the heating system expands, accompanied by an increase in pressure. Excess liquid enters the expansion tank (red arrow), and bends the membrane with its pressure (yellow arrow). At the same time, the volume of the chamber for the coolant increases, and the volume of the chamber for the air, respectively, decreases, and the air pressure in it increases.
• With a decrease in temperature and a decrease in the total volume of the coolant, the excess pressure in the air chamber contributes to the movement of the membrane back (green arrow), and the coolant moves back into the pipes of the heating system (blue arrow).

If the pressure in the heating system reaches a critical threshold, then the valve in the "safety group" should work, which will release excess fluid. Some models of expansion tanks have their own safety valve.

Different models of tanks may have own features designs. So, they are non-separable or with the possibility of replacing the membrane (a special flange is provided for this). The kit may include brackets or clamps for mounting the tank on the wall, or there may be stands - legs for placing it on the floor.

In addition, they may differ in the design of the membrane itself.

On the left is an expansion tank with a membrane - diaphragm (it has already been discussed above). As a rule, these are non-separable models. Often a balloon-type membrane is used (figure on the right), made of an elastic material. In fact, it is itself a water chamber. With increasing pressure, such a membrane is stretched, increasing in volume. It is these tanks that are equipped with a collapsible flange, which allows you to independently replace the membrane in the event of its failure. But the basic principle work does not change at all.

Video: device expansion tanks brand "Flexcon FLAMCO»

Prices for Flexcon expansion tanks FLAMCO

Flexcon expansion tanks

How to calculate the required parameters of the expansion tank?

When choosing an expansion tank for a particular heating system, its working volume should be a fundamental point.

Calculation by formulas

You can find recommendations to install a tank, the volume of which is approximately 10% of the total volume of coolant circulating through the circuits of the system. However, it is possible to carry out a more accurate calculation - for this there is a special formula:

Vb =Vwith ×k / D

The symbols in the formula are:

Vb- the required working volume of the expansion tank;

Vс- the total volume of the coolant in the heating system;

k- coefficient taking into account the volumetric expansion of the coolant during heating;

D- coefficient of efficiency of the expansion tank.

Where to get the initial values? Let's go in order:

1. The total volume of the system ( VWith) can be defined in several ways:

• It is possible to detect by the water meter what total volume will fit when the system is filled with water.
• The most accurate method that is used in calculating the heating system is the summation of the total volume of pipes of all circuits, the capacity of the heat exchanger of the existing boiler (it is indicated in the passport data), and the volume of all heat exchange devices in the premises - radiators, convectors, etc.
• Quite acceptable error gives the simplest way. It is based on the fact that 15 liters of coolant are required to provide 1 kW of heating power. Thus, the nominal power of the boiler is simply multiplied by 15.

2. The value of the coefficient of thermal expansion ( k) is a tabular value. It varies non-linearly depending on the heating temperature of the liquid and on the percentage of antifreeze in it. ethylene glycol additives. The values ​​are shown in the table below. The heating value line is taken from the calculation of the planned operating temperature of the heating system. For water, the value of the percentage of ethylene glycol is taken - 0. For antifreeze - based on a specific concentration.

Heat carrier heating temperature, °C	Glycol content, % of total volume
	0	10	20	30	40	50	70	90
0	0.00013	0.0032	0.0064	0.0096	0.0128	0.016	0.0224	0.0288
10	0.00027	0.0034	0.0066	0.0098	0.013	0.0162	0.0226	0.029
20	0.00177	0.0048	0.008	0.0112	0.0144	0.0176	0.024	0.0304
30	0.00435	0.0074	0.0106	0.0138	0.017	0.0202	0.0266	0.033
40	0.0078	0.0109	0.0141	0.0173	0.0205	0.0237	0.0301	0.0365
50	0.0121	0.0151	0.0183	0.0215	0.0247	0.0279	0.0343	0.0407
60	0.0171	0.0201	0.0232	0.0263	0.0294	0.0325	0.0387	0.0449
70	0.0227	0.0258	0.0288	0.0318	0.0348	0.0378	0.0438	0.0498
80	0.029	0.032	0.0349	0.0378	0.0407	0.0436	0.0494	0.0552
90	0.0359	0.0389	0.0417	0.0445	0.0473	0.0501	0.0557	0.0613
100	0.0434	0.0465	0.0491	0.0517	0.0543	0.0569	0.0621	0.0729

3. The value of the efficiency coefficient of the expansion tank ( D) will have to be calculated using a separate formula:

D = (Qm – Qb ) / (Qm + 1 )

Qm- the maximum allowable pressure in the heating system. It will be determined by the threshold of the safety valve in the "safety group", which must be indicated in the product passport.

Qb- pre-pumping pressure of the air chamber of the expansion tank. It can also be indicated on the packaging and in the product documentation. It is possible to change it - pumping with a car pump or, conversely, bleeding through a nipple. It is usually recommended to set this pressure within 1.0 - 1.5 atmospheres.

Expansion tank volume calculator

To simplify the calculation procedure for the reader, a special calculator is placed in the article, in which the indicated dependencies are included. Enter the requested values, and after pressing the "CALCULATE" button, you will receive the required volume of the expansion tank.