Closed heating systems. A closed heating system is the best choice for a private home

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Today, an open heating system is in steady demand, but at the same time it has a number of disadvantages that have an extremely negative impact on the efficiency of such a design (read: ""). The most important disadvantage is contact with the atmosphere: air in the system contributes to rapid wear of the pipeline and impairs system performance. It is to avoid this process that the heating system scheme was developed closed type, which is not influenced by the atmosphere.

Operating principle of closed type heating

What does a closed heating circuit look like? The main design feature, which determines the name of such a system, is its tightness. A closed-type heating system, the diagram of which includes elements, some of which are used in other types of heating, looks like this:

A closed heating system is protected from air ingress, but this process cannot be eliminated. For example, when adding liquid to the system, some air can still leak into the pipeline. Air trapped in the pipes will accumulate at the top of the system and form air pockets, which will impair the performance of the system and increase the risk of problems.

To drain the air that has entered the system, you can use a Mayevsky valve or float valves that operate automatically. If air has dissolved in water, it can be removed using separators that are installed directly in the pipeline.

To save heat, a closed-type heating system uses a thermostat that automatically turns the pump on and off when the room temperature changes.

Choosing a boiler for a closed heating system

A closed heating system in a private house can work with any type of fuel: you can use both gas devices, electricity and solid fuel. The choice of a suitable boiler should primarily be influenced by the results of calculations of the required heating output. You can entrust the calculations to a specialist, or you can do it yourself - but in this case, the result obtained will be approximate.

There are different types of heating boilers: single-circuit, double-circuit or with a boiler. In country houses, double-circuit boilers are often installed, since their efficiency in small areas is quite sufficient. A boiler equipped with a boiler is a little more convenient: it always contains hot water, and it does not need to be constantly refilled.

Selecting an expansion tank for closed heating

The coolant in heating systems of private houses is usually plain water. When heated, water tends to expand, thereby increasing the pressure in the system. If the pressure in a sealed system exceeds a critical point, a pipeline rupture may occur. How to make a closed heating system that will not damage pipes?

To solve this problem, expansion tanks were created that eliminate excess fluid, thereby preventing pressure build-up.

The expansion tank consists of two parts: a metal body and an elastic diaphragm, which is located inside and divides the body into two halves. The “back” part of the tank is filled with air or gas, and the expanded liquid enters the lower part. As the temperature rises, the water continues to increase in volume, affecting the membrane, which begins to shrink.

In case the pressure in the system nevertheless turns out to be critically high, there are safety valves (read also: " "). As the liquid cools, the diaphragm begins to expand, filling the closed-type heating system with water by displacing it from the tank.

The expansion tank is usually installed near the boiler.

Membranes in tanks can be of two types:

1. Fixed. Such a membrane is fixed around the perimeter of the expander and ensures stable operation, but if it is damaged, the entire tank will need to be replaced.
2. Replaceable. Membranes of this type usually produced as bulk rubber products that are filled with water. Replaceable membranes are installed on the tank flange, and if they rupture, you can replace them yourself.

Conclusion

The heating system is an important element of the house, and its calculation must be carried out in accordance with all rules. The question of which is better: a closed heating system with your own hands or one built by professionals remains open, but it is not the most important.

It is very important to choose the right system elements that will ensure maximum efficiency and cost-effectiveness, are reliable and of high quality. A closed heating system, the diagram of which is shown in the photo, can become excellent choice ensuring that all requirements are met.

If everything was done correctly, the closed heating system will heat the building for many years, creating a cozy and comfortable environment.

The heating system of a private house is a sequence of elements connected by pipes through which coolant circulates. The temperature is usually unstable, sometimes higher and sometimes lower. Along with the temperature, the volume of the coolant increases/decreases, since it, like any liquid, expands when heated, increasing in volume, and contracts when cooled. To prevent pipes or radiators from bursting when heated, install special device– an expansion tank into which excess coolant is forced out at high temperatures. From there, when the temperature drops, it comes back into the system. This way it is supported stable pressure in the heating circuit (within certain limits). The tank can be of an open or closed type, respectively, and the system is then called open or closed.

Open and closed heating system

If an open type expansion tank is installed, then the system is called open. In its simplest form, it is some kind of container (saucepan, small plastic barrel, etc.) to which the following elements are connected:

Today, open systems are made less and less often, and all because it is constantly present a large number of oxygen, which is an active oxidizing agent and accelerates corrosion processes. When using this type, heat exchangers fail much faster, pipes, pumps and other elements are destroyed. In addition, due to evaporation, you have to constantly monitor the coolant level and periodically add it. Another drawback is that it is not recommended to use antifreeze in open systems due to the fact that they evaporate, that is, they are harmful. environment, and also change their composition (concentration increases). That’s why closed systems are becoming more and more popular - they exclude the supply of oxygen, and the oxidation of elements occurs much slower because they are considered better.

In closed systems, membrane-type tanks are installed. In them, the sealed container is divided into two parts by an elastic membrane. Below is the coolant, and top part filled with gas - ordinary air or nitrogen. When the pressure is low, the tank is either empty or contains a small amount of liquid. As the pressure increases, an increasing amount of coolant is forced into it, which compresses the gas contained in the upper part. To prevent the device from bursting if the threshold value is exceeded, an air valve is installed in the upper part of the tank, which is activated at a certain pressure, releasing part of the gas and equalizing the pressure.

Advantages and disadvantages

In addition to the fact that oxidation in a closed system occurs more slowly, they have several other advantages:

• the coolant does not evaporate, there is no contact with external environment, which allows you to use not only water, but also special compounds that increase heating efficiency and improve its characteristics;
• higher pressure and circulation speed of the coolant, therefore its silent movement through the pipes.

With proper heating organization, the difference between the return and supply temperatures is small, which has a positive effect on the duration of operation of the boiler (an exception is, but there is a different operating principle).

Single-pipe open-type circuit - the expansion tank is installed at the top point

There are few disadvantages:

• For efficient work active movement of the coolant is required, which is achieved either by installing a pump or creating natural circulation with sufficient slopes;
• at large volume system requires tank big size, a place for which is not easy to find (its volume should be 10% of the coolant volume).

Monitoring the performance of a closed system

The main indicator of performance is pressure. It is controlled by pressure gauges. For individual closed heating systems with forced circulation operating pressure is 1.5-2 Atm. Moreover, it is advisable to embed pressure gauges into key points through three way valves, which make it possible to remove the device for repair/replacement, blow it out or reset it to zero.

If the system is large and powerful, then there are many control points (pressure gauges):

• on both sides of the boiler;
• before and after the circulation pump;
• when using heating regulators - before and after them;
• It is advisable to install mud traps and filters before and after them to control the degree of clogging.

Using pressure gauge readings at these points, you can monitor the performance of the entire system.

What to do if the pressure in the system drops/increases

If you notice a decrease in pressure, the first thing you need to do is turn off the pump. And then act based on the pressure gauge readings:

• If the static pressure also drops, there is a leak somewhere. It is necessary to inspect all the elements and eliminate it. Please note that even a very small hole (less than a millimeter) can be the cause, so it can be difficult to find the damage. If the pipeline is long, you can localize the leak area by disconnecting the branches one by one. As soon as the fall has stopped, the area is determined - depressurization on the one that was just turned off.
• If the pressure is stable when the pump is turned off, the pump has failed and needs to be repaired or replaced.

An increase in pressure is observed less frequently, but it also happens. It is usually caused by an increase in temperature in the system, and it rises due to insufficient coolant circulation. But why the coolant circulates poorly needs to be understood.

• First, we check the functionality of the pump. Let's turn it off and watch. If the pressure continues to rise, the problem is not with the pump. If it stabilizes, it’s his fault.
• We clean filters and dirt traps.
• If the pressure still rises, an air lock may have formed - bleed the air in the system.
• If this does not help, we check the condition of the shut-off valves - maybe someone accidentally or intentionally closed it, blocking the flow of coolant.
• Another reason is that due to a breakdown or failure of the automation system, the system is under constant recharge.

Using this algorithm, you can independently determine the cause of the abnormal condition of the heating system and eliminate it.

How to deflate

Now a little about how to bleed air in a closed system. It all depends on the type of wiring. If the wiring is lower, Mayevsky taps are installed on each radiator. Air is vented through them in each battery. To do this, use a special key or screwdriver to turn the lock located in the center. If there is air, you can hear hissing and if water flows, it is not a steady stream, but like carbonated water. When the air is released, the stream flows smoothly. So they go around all the radiators in a circle several times. Since with bottom wiring the tops of the radiators are practically the highest points of the entire system, all the air accumulates in them.

To bleed air from the system, install a Mayevsky valve on the radiators

If the system has a bypass circuit (for example, above the door), the upper points are above the level of the batteries and boiler. Then in the circuit they put bleed valve, through which air is automatically removed.

At top wiring similar drain valves are installed at the upper supply points. They also operate automatically, preventing the flow from clogging. In many modern boilers, the same valves are installed in built-in safety groups. If there is no such device, install pumps with deaerators. Even if there is a valve in the boiler, when designing the system, it is better to provide for their installation at the highest points: the costs are low, and operation becomes easier.

Bleed valve - automatically vents air

How to create pressure in a closed heating system

For rapid movement of the coolant through the pipes, a certain pressure must be created. Its value is determined by the type of system - for natural circulation the pressure should be only slightly higher than atmospheric pressure, and this will be sufficient, but for forced circulation its value is required as high as possible, but not exceeding 2 Bar.

The gravity flow system is single-pipe with vertical distribution into two wings (circuits). A slope is required for normal operation

To create the required pressure drop, it is necessary to maintain a slope of 1 cm per 1 meter of pipeline length. On the supply line the slope goes down from the boiler. On the return side, on the contrary, the pipes go down to the boiler with the same height difference. When using pipes of insufficient diameter, this value may not be enough, then the slope can be increased to 5% (5 cm per meter of pipe). In general, for a normal gravity system, careful selection of pipe diameters and slope is necessary - only then will it work normally.

The EC scheme requires the mandatory installation of a safety group, which includes a pressure gauge and a blast valve set to the operating pressure. As the pressure increases, the valve will operate, preventing the “weakest” element from rupturing. This situation can happen when using a boiler without automatic control, in particular a solid fuel boiler, which either gets very hot or almost goes out. This group also helps out in case of automation failures.

Types of closed heating system diagrams

The main advantage of natural circulation schemes is their independence from the availability of electricity, but they have a limitation: the length of the circuit must be no more than 30 meters, otherwise the system will be inoperable. There is one more nuance - with natural circulation, even in a closed system, you need to install a drain valve at the top point, with the help of which you can remove air that has entered, for example, when adding coolant.

Natural circulation system one-story house. Single-pipe circuit, top wiring

In circuit c, pressure is created by a circulation pump. Some boilers have it built in, some don't. Some long circuits require the installation of two pumps. Then it is not necessary to observe slopes; the most important thing is not to make the sections slope in the other direction, which will negatively affect the performance of the heating and may even require rework.

On the one hand, the use of circulation pumps is a disadvantage, since its performance depends on the availability of electricity, but on the other hand, it is a big plus:

• allows you to use pipes of a smaller cross-section and radiators of a smaller volume, which means you spend less money on purchasing materials;
• increase the speed of movement of the coolant, and therefore reduce its inertia and increase the level of comfort;
• less coolant, less fuel is wasted on heating it - money is saved.

Reduced volumes of pipes and radiators mean a decrease in the volume of the system, which again makes it possible to reduce the heating inertia of the coolant - it heats up faster, and the heating is more efficient. Less coolant volume – less volume expansion tank, and there is no need to look for a place to install it. Modern boilers have built-in membrane tanks (for example), and the heating efficiency using them is very high due to the fact that a powerful pump is installed (it is also built-in).

It is better to connect the pump with a bypass - to be able to repair/replace it without destroying the system

When choosing a pump, remember that there is a direct relationship between its power and heating efficiency. Therefore, choose one that is low noise, powerful and reliable.

It is worth noting that it is easy to make a closed one from an open system - you just need to change the expansion tank - install a membrane type and the system will be operational. To make it more efficient, you will need to install a pump. Moreover, modern pumps can be installed in both supply and return. Previously, they were installed on the return line because the coolant temperatures there are lower. But modern pumps use heat-resistant materials; the temperatures of heating systems are not so critical for them. Just when buying, pay attention to the operating temperature range, or put it in the return line - only so that it “presses” into the boiler. In this case, the pump power may be small, since open systems use larger pipe diameters than closed ones, and the hydraulic resistance of the system is small.

Results

There are many nuances and features in heating a private home, and it’s not easy to figure it out. But once you set a goal, you can do everything with your own hands - create a workable good project, choose the right equipment and install everything yourself. And closed systems in this sense are no exception.

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 home, the heating system becomes a mandatory attribute of your residence. The heating system is thought out in detail and calculated at the stage of the construction (or reconstruction) project of the facility - it is designed for many years of operation, and correcting errors in the future will be very expensive.

Closed heating system of a country house.

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

Components of a closed system and their purpose

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

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

1. It is best to choose an automatic source of thermal energy (boiler). This makes it possible to operate the heating system in autonomous mode according to preset parameters, depending on the outside temperature and the level of desired comfort. In this regard. In addition, today they are the most economical. Thanks to the sensitive thermostat, the temperature can be set to the nearest degree - very convenient and economical.

Wall-mounted Hermann gas boiler without decorative casing.

Electric boilers are not inferior to gas boilers in terms of automation level, but for heating large areas, energy consumption 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 current electricity tariffs cannot compare with their 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 this is still a rather troublesome option: their level of automation is minimal, and you still have to prepare and throw firewood (coal, sawdust, etc.) into the firebox manually. But sometimes this is the only option 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 circuit of the heating system under the influence of the centrifugal force created by the circulation pump. As the temperature rises, the volume of the coolant increases, creating excess pressure. When it reaches a critical value, it opens safety valve, the excess coolant volume enters the expansion tank, and the pressure drops to the nominal value. After the boiler is turned off (usually done automatically at the command of a 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 while the boiler is operating.

Video

An important question that arises after the installation of heating devices is completed concerns how to fill a closed-type heating system and put it into operation. The process is simple, although its features cause typical difficulties for ordinary users. These include the choice of injection point and coolant pressure.

Open and closed heating systems: filling principle

Open system equipped with an expansion tank at its highest point. The surface of the coolant fluid in it is in direct contact with atmospheric air. The closed system is equipped with a membrane expansion tank, hermetically sealed from the atmosphere.

Heating systems of any type can be filled as follows:

• tap water supplied to the lowest point of the system - through the make-up valve;
• water (distilled) or antifreeze, supplying liquid from a container (well, reservoir):
• by pouring manually and/or using a pump to the top point (fitting under the air vent or through an open expansion tank);
• pumping through the lowest point - the make-up inlet.

Many homeowners know the simplest (and worst!) way to fill open systems through an expansion tank. Water/antifreeze is poured inside with breaks to release air. It is not recommended to repeat this method in closed systems using the pipes of the upper air vents. The air that initially fills the system passes up through the layer of water being poured, dissolving in it. Air locks that prevent the flow of water through pipes and radiators will be guaranteed.

Then how to fill a closed heating system? The recommended method of filling any heating systems is to supply fluid under pressure (from a water supply or container via a pump) through the bottom fill valve.

Location of the heating system make-up unit.

When filling with coolant

There are only two known situations that require this technological operation:

• putting the heating system into operation (at the beginning heating season);
• restart after repair work.

Usually the coolant water is drained late spring for two reasons:

1. Water inevitably becomes contaminated with corrosion products (inside radiators, metal-plastic and polypropylene pipes are not subject to it). Leaving the old water on new season, you risk breaking the circulation pump with solid contaminants.
2. Unstarted flooded systems country houses may “defrost” during a sudden cold snap - such cases are not uncommon. In this sense, antifreeze coolant is preferable. The high-quality composition has high anti-corrosion properties, increasing the drain interval to 5-6 years. There are known cases of uninterrupted heating operation with the same volume of antifreeze for 15-17 years. It is recommended to drain low-quality antifreeze after 2-3 years.

Pumping antifreeze into the heating system.

Filling technology: where to supply coolant

The necessary means are a container and a pump that creates the required pressure coolant liquid. Submersible type “Gnome” or “Kid” are quite suitable (popular with gardeners who use them for watering areas located above the levels of reservoirs). There is evidence of successful filling of closed systems using hand pumps - from those used for spraying protective solutions garden crops, to specialized hand pumps used for pumping motor fuels or liquid chemical products from barrels. Any heating circuit can be successfully filled by monitoring the pressure using a pressure gauge.

Filling the system with antifreeze using a submersible vibration pump.

The first step is to select the fluid entry point. If the pressure created by the pump raises the liquid to the top of the system, it should be connected at the lowest point of the boiler room - the coolant make-up pipe, cut into the “return” in front of the boiler. In addition to the make-up inlet, a structurally separate drain outlet is required (two different system components). The first is equipped with a valve (ball valve) and a check valve, the second - only with a valve (ball valve). If nadir system is the water drain fitting from the boiler, you can drain/fill the system with water through it. Since a check valve is not installed behind the boiler drain (behind the drain at all), any shutdown of the pump will cause the pumped liquid to leak out - you need to quickly turn off the tap in front of the fitting.

Design of a typical drain/recharge unit.

Filling the system from below

So, let's get back to pumping fluid into the system. We use a container of suitable volume (a 200-liter plastic barrel works well). We lower a pump into it, creating the pressure required for pumping liquid no higher than 1.5 atm (typical value in the range of 1-1.2 atm). Such pressure requires the pump to create a pressure of 15 m (for the submersible “Malysh” it reaches 40 m).

Having filled the barrel with water, we start the pump, monitoring the liquid level, which should be located above its inlet pipe to prevent “airing”. The level drops - add water. Antifreeze should be pumped from a smaller container (bucket) so as not to immerse the submersible pump housing in the liquid (and then wash it) - just immerse the inlet pipe. You will have to add antifreeze frequently, turning off the pump periodically.

Filling the system is carried out with Mayevsky taps open on installed heating radiators with substitute containers for collecting water. When liquid comes out of all air vents, close the taps and continue the injection process.

We control the pressure using a pressure gauge (a boiler gauge will do). When its value exceeds the hydrostatic pressure, equal to the pressure in the liquid column height from the bottom to the top point of the system (a height of 5 m gives a static pressure of 0.5 atm), we continue to fill the system, monitoring with a pressure gauge the moment the pressure reaches the required value.

Pumping antifreeze with the “Malysh” pump.

Having filled the system, turn off the pump, open the air valves (the pressure will inevitably drop), and then pump up the water. We repeat the process several times, displacing air bubbles.

We complete the filling by inspecting the system for leaks. After the pump is turned off, the liquid in the hose connected to the outlet pipe is under pressure. If antifreeze was pumped in, first disconnect the hose from the pump inlet pipe and drain the liquid into a container, being careful not to drench the mechanism body.

How to properly fill a closed heating system from above

If there is no electric pump, then filling the system, which has a height difference between the lower and upper points of 10 m, using a hand pump is a rather tedious procedure. In this case, the closed system can be filled through the upper point (for example, the connection fitting of an automatic air vent) by gravity with the drain valve open at the lower point until water begins to flow out of it. The drain valve closes, and at the bottom point of the system we have static pressure equal to the pressure in the liquid column up to the top point (at 10 m the pressure will be 1 atm).

Now you need to increase the pressure to a design level of no higher than 1.5 atm. We connect to any fitting of the system via ball valve ordinary watering hose about 1.5 meters long. We are coming up with an easily removable adapter for it to the hose of a regular car pump with a pressure gauge. We fill the vertically straightened hose with water, attach a pump through the adapter and pump water from the hose into the system with air. Close the ball valve. 3-5 repetitions of the process are enough to increase the initial static pressure at any point in the system by 0.5 atm. Avoid pumping air into it.

Injecting antifreeze with a hand pump.

Selecting pressure values ​​in the system and expansion tank

The higher the operating pressure of the coolant, the less likely it is that air will enter the system. It is necessary to remember that the operating pressure is limited to the maximum permissible value for the heating boiler. If, when filling the system, a static pressure of 1.5 atm (15 m of water column) was reached, then the circulation pump with a pressure of 6 m of water. Art. will create a pressure of 15 + 6 = 21 m of water column at the entrance to the boiler.

Some types of boilers have a working pressure of about 2 atm = 20 m water column. Be careful not to overload the boiler heat exchanger. high pressure coolant!

The membrane expansion tank is supplied with a factory set pressure of inert gas (nitrogen) in the gas cavity. Its common value is 1.5 atm (or bar, which is almost the same). This level can be raised by pumping air into the gas cavity with a hand pump.

Initially, the internal volume of the tank is completely occupied by nitrogen, the membrane is pressed against the body by the gas. That is why closed systems are usually filled to a pressure level of no higher than 1.5 atm (maximum 1.6 atm). Then, by installing the expansion tank on the “return” in front of the circulation pump, we will not get a change in its internal volume - the membrane will remain motionless. Heating the coolant will lead to an increase in its pressure, the membrane will move away from the tank body and compress the nitrogen. The gas pressure will increase, balancing the coolant pressure at a new static level.

Pressure levels in the expansion tank.

Filling the system to a pressure of 2 atm will allow the cold coolant to immediately press the membrane, which will also compress the nitrogen to a pressure of 2 atm. Heating water from 0 °C to 100 °C increases its volume by 4.33%. The additional volume of liquid must enter the expansion tank. The large volume of coolant in the system gives a large increase in its growth when heated. Too much initial pressure of the cold coolant will immediately use up the capacity of the expansion tank; it will not be enough to receive excess heated water (antifreeze). Therefore, it is important to fill the system to the correctly determined coolant pressure level. When filling the system with antifreeze, you need to remember that its coefficient of thermal expansion is greater than that of water, which requires the installation of a larger capacity expansion tank.

Conclusion

Filling closed heating systems – not just standard final operation before putting into operation. Correct or incorrect execution of this step can seriously affect the performance of the system, in the worst case, even destroy it. Compliance with filling technology is the key to obtaining stable heating.

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What and how to fill the heating system in a private house: choice of coolant, solutions for open and closed systems

What liquids can be used as a coolant? How to start the heating for the first time after its installation is completed? What should be the operating pressure of a cottage heating system? Today we have to answer these and some other questions.

Our task is to fill the empty water heating circuit.

Selection of coolant

First, a few words about what liquids can be used to fill the heating system. Here are the key properties of popular coolants.

Water

• Price: minimal (when pumping from a water supply with a water meter installed at the entrance to the house - from 20 rubles per cubic meter);
• Heat capacity: high (4183 J/(kg deg) at +20°C);
• Viscosity: low (which means little load on the circulation pump);
• Corrosivity: average (steel in contact with water rusts only in the presence of oxygen);
• Toxicity: none;
• Expansion coefficient when heated: 0.03%/deg.

For heating it is better to use distilled water, which is non-conductive. electricity and having minimal corrosive activity.

Antifreeze

Antifreeze was developed several decades ago as a winter filler for water cooling systems of automobile engines. Nowadays, it is often used as a winter coolant. The numerical designation in the marking of antifreeze (30, 40 or 65) means its freezing temperature.

• Price: from 40 rubles per kilogram for wholesale supplies and from 60 for retail sales;
• Heat capacity: average (3520 J/(kg deg));
• Viscosity: high (the load on the pump increases due to an increase in the hydraulic resistance of the system);
• Corrosive activity: low due to anti-corrosion additives;
• Toxicity: high (the original antifreeze contains toxic ethylene glycol);
• Expansion coefficient when heated: 0.05%/deg. The higher the expansion coefficient, the larger the expansion tank must be in a closed heating system. It is this that compensates for the expansion of the coolant as the temperature rises.

Antifreeze is antifreeze for water cooling systems of engines.

Due to zero corrosive activity, antifreeze creates leaks at the slightest violation of the tightness of the heating circuit. Water and other coolants quickly clog small leaks with rust and crystallizing mineral salts.

Propylene glycol

Non-freezing coolants are produced on the basis of propylene glycol, designed specifically for heating systems.

Packaging of coolant based on propylene glycol.

• Price: from 100 rubles per kilogram;
• Heat capacity: low (2400 J/(kg deg));

Propylene glycol is used in the form of an aqueous solution. Mixing with water increases its heat capacity to the level of antifreeze (3500-4000 J/(kg deg) depending on the proportion of the mixture).

• Viscosity: high;
• Corrosivity: low due to additives;
• Toxicity: zero (canisters with coolant are marked green and the designation “Eco”);

Polypropylene glycol mixed with glycerin is used as a cosmetic product.

• Expansion coefficient when heated: approximately 0.05%/degree.

Brine

Concentrated solution table salt, calcium chloride and other salts can also be used as a coolant: its freezing point is inversely proportional to the salt concentration. These are a typical budget solution, which is limited to use only in open systems with natural circulation.

• Price: from 5 rubles per 1 kg of table salt;
• Heat capacity: low (at 30 percent concentration - 2700 J/(kg deg);
• Viscosity: low;
• Corrosive activity: extremely high. Salt literally corrodes steel pipes;

This is how contact with steel acts on steel. sea ​​water- brine with a small concentration of salts.

• Toxicity: zero;
• Expansion when heated: approximately 0.03%/deg.

At high brine concentrations and slow movement of the coolant in the system, excess salts will gradually be deposited on the walls of the pipes, reducing their cross-section. In a forced circulation circuit, brine has a detrimental effect on the pump: the shaft and impeller become overgrown with crystals, which leads to a drop in performance.

conclusions

The instructions for choosing a coolant are quite obvious:

1. If you have the opportunity to maintain a positive temperature in your home throughout the heating season, heating circuit It's best to fill with water. It is better to use distilled water, but you can also use drinking water or even well water;
2. If the cottage is periodically left without heating, your choice is non-freezing coolants based on propylene glycol.

The freezing point of antifreeze depending on the concentration of the solution.

A time to reset and a time to fill

When do you have to fill the heating circuit?

In just three cases:

1. When you first start;
2. After repair of shut-off and control valves, boiler, bottling, replacement of heating devices, etc.;
3. After resetting the heating system for a long winter period of inactivity. It is practiced if the circuit is filled with water and the house remains without heating for a long time.

To completely drain the circuit, vents must be placed on all brackets below the bottling level. When resetting, you need to open at least one vent at the top point of the circuit so that it sucks in air.

In the photo there is a discharge brought to the street, located at the lowest point of the heating outlet of my house.

Open system

Autonomous heating can operate according to two fundamentally different schemes:

A peculiarity of the installation of an open heating system is that its bottlings (supply and return) are laid with a constant slope from the open expansion tank at the top point of the circuit.

This pipe layout has two practical consequences:

1. You can pour water into the system directly through the expansion tank (in buckets or through a water supply tap located in the attic);

The open tank device allows you to fill the heating circuit using buckets or any other container.

1. All the air remaining in the circuit at the time of filling will be displaced there.

How to run such a system with your own hands? It’s as easy as shelling pears: fill the circuit and light the boiler. If the circuit is designed to operate with natural circulation, circulation will begin immediately after the boiler heat exchanger warms up. In a system with a pump, you must additionally turn on its power.

Closed system

How to fill a closed heating system with water or antifreeze?

The fittings can provide partially automated and manual filling of a closed-type heating system. In the first case, its set looks like this:

The safety group and expansion tank are often located in the housing of a single-circuit or double-circuit boiler with electronic control. In this case, the readings of the pressure sensor, which replaces the pressure gauge, are displayed on the front display panel of the device.

When filling the circuit with water from the cold water system most of air is forced out through the automatic air vent of the safety group (immediately upon filling and when the circulation pump is turned on). After startup, all that remains is to bleed the air from individual devices through Mayevsky’s taps. The filling pressure is controlled by a pressure gauge.

The tap for feeding my heating system from hot water supply.

How to properly fill a closed heating system if there is no power supply from cold water supply?

To pump water, you will need a vent installed at the top of the circuit (a ball valve pointing upward) and... a bicycle pump.

It is necessary to bleed all the air from the expansion tank through the spool, fill the circuit with water through the funnel inserted into the vent, close the vent and re-pump the expansion tank to operating pressure (1.5 kgf/cm2).

Manipulations with the air pressure in the expansion tank are possible even if it is mounted in the boiler body.

Conclusion

As you can see, starting an autonomous heating circuit is not particularly difficult. The video in this article will help you learn more about it. Feel free to add and comment on it. Good luck, comrades!

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How to fill water into a closed heating system with or without plumbing?

Arkady How to fill water into a closed heating system?

No heating system will function without a coolant, because it directly ensures the transfer of energy to radiators and subsequent heating of the air in the room. So after installation and repair work, you will inevitably need to pour new water into the equipment. For many, this procedure seems overwhelming. Especially if you need to fill a closed system. Indeed, the task is troublesome, but at the same time absolutely achievable if you do everything according to the rules - they will be discussed further.

Preparatory operations

Before you start pouring coolant into a closed heating system, prepare it for operation. In particular, the following procedures should be followed:

• Hydraulic test - before filling the system, it must be pressurized. This is done using a special device that applies pressure and fills compressed air all pipes and batteries. Pressure testing is performed at a pressure 25% higher than the base pressure for a specific heating system.
• Checking for problems - after completing the pressure test, you should check all joints of the heating equipment for depressurization and leaks. If there are any problems, they need to be corrected.
• Shutting off the valves - to avoid unplanned water consumption when filling, shut off the shut-off valves that drain liquid from the system.

When the preparatory work is completed, you can start pouring water. It can be run from a centralized water supply or, in the absence of the latter, from another source of water - we will consider both options.

Hand pump for pressure testing the heating system

Filling water from the water supply

If your home is connected to the water supply network, there will be no problems filling the heating system. First, you need to determine which fittings are closest to the heating boiler - it is through it that the coolant should be introduced.

Next, the heating boiler must be connected to a centralized water supply and a special shut-off valve must be installed between them. Filling is carried out precisely thanks to this valve: when it is opened, water begins to flow from the water supply into the boiler, which is then poured into the pipeline.

Important! Water must enter the heating system at a minimum speed - this will allow the air that remains in the pipeline to be removed without consequences through special Mayevsky battery-powered taps.

If the house has more than one floor, the system can be filled not at once, but in parts: starting from the lower radiators and ending with the upper heating points.

Filling water without running water

If the source of coolant is not a centralized water supply, but a well, a well or a reservoir, auxiliary equipment will be required to fill a closed heating system. This could be a powerful pump or an expansion tank.

Heating system diagram

In the first case, you will need a manual or electric pumping unit. With its help, filling is performed according to the following scheme:

1. Connect the pump hose to the drain pipe.
2. Open the special valve on the pipe.
3. Open the Mayevsky taps.
4. Start the pump and begin running water into the system.

In the second case use membrane tank with a partition into two parts and a regular bicycle pump:

1. Connect the tank to the heating system pipeline and fill it with water.
2. Unscrew the nipple at the top of the expansion tank and bleed the air from the tank.
3. Connect the bike pump to the nipple and begin pumping air into the tank, creating pressure to force water into the system.

Advice. Pump the tank until the pump pressure reaches 1.5 atm.

Now you know that you can pour water into a closed-type heating system either from a water supply or without it. The main thing in both cases is to carefully prepare for the procedure and observe all the technical details of the work. So, if you follow the rules, filling the system will not be an overwhelming task for you.

Filling the heating system: video

sandizain.ru

Options for pouring water into a closed heating system

Heating a private home » Heating installation

Procedure

Before you figure out how you can pour water into a closed-type heating system, you need to decide on the system itself and find out what elements it consists of and why it is called that.

Let's start with the fact that there are two types of it:

In the first case, the coolant comes into contact with outside air through an expansion tank, which is installed at the highest point of the heating network. The expansion tank itself performs the function of collecting coolant, which expands as the temperature rises. One of the physical laws applies here. Typically, an open heating system is used if the principle of natural coolant circulation is applied.

We will talk about closed-type heating. From the name itself it is clear that this system is sealed, and in it the coolant does not come into contact with the outside air. A distinctive feature of this type is the presence of two elements - a circulation pump and a membrane expansion tank. It turns out that a closed-type heating system uses the principle of forced circulation of coolant.

And just a few words about the membrane expansion tank, because it plays one of the most important roles. This is a sealed structure, separated inside by a rubber membrane. The lower part is usually filled with coolant, and the upper part is filled with air pumped inside at the factory under a pressure of 1.5 kg/cm² (atm.). When expanding, the coolant presses on the membrane, raising it to a certain level. Air under pressure resists this. It turns out that inside the heating network the coolant pressure will always be 1.5 atm.

Closed heating circuit

Now about the heating itself. If the house has a centralized water supply network, then there will be no problems with filling. In the water supply system, water is always under pressure of 3–4 atm, and this is enough to fill the heating network. To do this, the boiler is connected to the water supply, and a shut-off valve is installed between them. When it is opened, it is filled, and the air inside the system is released through Mayevsky valves installed on the radiators.

To drain the coolant, a drain pipe with a valve is installed at the lowest point. This important element heating circuit when it comes to pouring water into it in the absence of running water in a country village.

Heating system diagram

The options for filling closed-type heating are as follows:

1. You will need a pump that can be used to draw water from a well, well, or any open body of water. The pump discharge hose is connected to the drain pipe, on which the valve opens. This gives you direct access to heating. This is how you can fill a closed-type heating system. In this case, all available taps open completely. This is especially true for Mayevsky taps, through which air from the inside is exhausted to the outside.

Please note that the supply pump may have a pressure greater than that required for heating. Therefore, be sure to monitor this indicator using a pressure gauge installed in the pipeline or in the boiler.

2. What is 1.5 atm? This water pressure, equal to 15 meters of water column. That is, by raising a water tank to a height of 15 m, you can achieve the required pressure inside the system. If you don’t have a pump at hand and you use water from a well, then you can fill the heating circuit by raising the hose to a height of 15 m, and then pour water into it in buckets. The hose, as in the case of the pump, is connected to the drain pipe. Let's face it - the option is not the best, but it can be used as an alternative.
3. And now, regarding the expansion tank. It is usually attached to the pipeline threaded connection. It will be very easy to remove it. An open pipeline is a great place to add water. To do this, you need to prepare a funnel to make the filling process easier. As soon as water appears in the pipe, we can assume that the system is completely filled. After all, the location where the tank is installed is the highest point in the heating system. Although in closed systems this is not always the case. After this, you can install the tank in place.

Tank structure

When using the last filling option, the question arises how to create required pressure? Everything is simple here. At the top of the expansion tank there is a nipple, which is used to bleed air if there is a situation with excess pressure inside the tank. So the nipple can be easily removed. A hose from a regular bicycle pump is applied to the hole from the nipple, and the pumping is done last. Pay attention to the pressure gauge - as soon as the indicator reaches 1.5 atm, stop pumping.

Here's how to fill a closed heating system. Of course, the best option is to use a pump to pump water. By the way, you can take a low-power unit. To do this, install a metal barrel or other tank near the house, fill it with water from an open reservoir in buckets (you can use collected rainwater), connect the pump to the heating, and lower the other hose (suction) into the barrel. If the volume of the tank is less than the required volume of coolant, when operating the pumping device, carry water in buckets and pour it into the barrel.

And the last thing regarding bleeding air. This is a serious and difficult matter. You will have to bleed it from each heating device. This will take some time, but this procedure cannot be neglected. There should not be any bubbles left inside the system as this will affect the operating efficiency.

Conclusion on the topic

The closed circuit type is the most effective. The fact is that the coolant begins to evaporate at high temperatures. And if there is a way out for the vapors, the volume of the coolant will decrease. You will have to constantly monitor this and fill the network with water through a water pipe or buckets. In cases with buckets, this causes a lot of trouble. But all this can be avoided.

If a country house is designed not only for the periodic arrival of its owners during the summer season, but for their long-term or even permanent residence in it, then there is no way to do without a heating system. This issue is always carefully thought out at the design stage of construction or reconstruction, and is taken into account when purchasing ready-made housing.

This question is extremely serious, requiring scrupulous consideration of all existing conditions: periods of future operation of the building, climate zone terrain, the presence of power supply lines, utilities, building design features, the total estimated cost of implementing a particular project. And yet, most often, homeowners come to the conclusion that the optimal solution would be a closed-type water heating system in a private house.

This publication will discuss basic principles closed system, its differences from a covered one, existing advantages and existing disadvantages. Attention will be drawn to the main elements of such a system with recommendations for their selection, given standard schemes wiring of the heating network inside the house.

Closed heating system in a private house - main features

A private house can be heated in different ways.

• For a long time, the main source of heat was one or more stoves (fireplaces), each of which heated one or another section of the building. The disadvantages of this approach are obvious - uneven heating, the need to conduct regular fires, monitor the combustion process, etc.

Stove heating- it’s already “yesterday”

Currently, this type of heating is used less and less, and, as a rule, when it is absolutely impossible or completely inappropriate to use another, more efficient system.

• System electric heating using convectors or oil radiators– extremely expensive to operate due to the high price of electricity and its high consumption.

True, alternative methods are emerging, in the form of film infrared elements, but they have not yet gained widespread popularity.

• Most owners of private houses still opt for water heating. This is a proven efficient system, which, by the way, can work from almost all energy sources - natural gas, liquid or solid fuel, electricity, which makes it completely universal - the only difference is in the type of heating boiler. A well-calculated and correctly installed water heating system ensures uniform heat distribution throughout all rooms and is easy to adjust.

Not so long ago, the main scheme for organizing water heating in a private house was open with the gravitational principle of moving the coolant through pipes and radiators. Compensation for the thermal expansion of water occurred due to the presence of a leaky tank, which was installed at the highest point of the entire circuit of the heating system. The openness of the tank, of course, causes constant evaporation of water, so there is a need to constantly monitor its required level.

The movement of the coolant through the pipes is ensured in this case by the difference in the density of cold and heated water - the denser cold water seems to push the hot water forward. To facilitate this process, an artificial slope of the pipes is created along their entire length, otherwise the effect of hydrostatic pressure may occur.

It is quite possible to install a circulation pump into an open system - this will dramatically increase its efficiency. In this case, a valve system is provided so that it is possible to switch from forced circulation to natural circulation and back if necessary, for example, during power outages.

The closed type system is structured somewhat differently. Instead of an expansion tank, a sealed compensation tank for the membrane or balloon type. It absorbs all thermal fluctuations in the coolant volume, maintaining closed system one pressure level.

The main difference between a closed system is the presence of a sealed expansion tank

IN currently this the system is the most popular because it has many significant advantages.

Advantages and disadvantages of a closed heating system

• First of all, the coolant does not evaporate. This gives one important advantage - you can use not only water, but also antifreeze. Therefore, the possibility of the system freezing during forced breaks in its operation is eliminated, for example, if it is necessary to leave the house for a long time in the winter.
• The compensation tank can be located almost anywhere in the system. Usually a place is provided for it right in the boiler room, in close proximity to the heating device. This ensures the compactness of the system. An open-type expansion tank is often located at the highest point - in an unheated attic, which will require its mandatory thermal insulation. In a closed system, this problem does not exist.
• Forced circulation in a closed-type system ensures heating of the premises much faster from the moment the boiler is started. There is no unnecessary loss of thermal energy in the expansion area tank.
• The system is flexible - you can adjust the heating temperature in each specific room, and selectively turn off some sections of the general circuit.
• There is no such significant difference in the temperature of the coolant at the inlet and outlet - and this significantly increases the time of trouble-free operation of the equipment.
• For heating distribution, pipes of a much smaller diameter can be used than in an open system with natural circulation without any loss of heating efficiency. And this is both a significant simplification of installation work and significant savings in material resources.
• The system is sealed, and when properly filled and normal operation valve system there simply should not be any air in it. This will prevent the appearance air jams in pipelines and radiators. In addition, the lack of access to oxygen contained in the air prevents corrosion processes from actively developing.

You can also include “warm floors” in a closed heating system

• The system is highly versatile: in addition to conventional heating radiators, it can be connected to water-based “warm floors” or convectors hidden in the floor surface. A water heating circuit for domestic needs is easily connected to such a heating system - through an indirect heating boiler.

There are few disadvantages to a closed heating system:

• The expansion compensation tank must have a volume larger than with an open system - this is due to the peculiarity of its internal design.
• Mandatory installation required so-called "security group"– safety valve systems.
• The correct operation of a closed forced-circulation heating system depends on the continuity of the electrical supply. It is possible, of course, to provide, as with the open type, a switch to natural circulation, but this will require a completely different arrangement of pipes, which can reduce a number of the main advantages of the system to zero (for example, the use of “warm floors” is completely eliminated). In addition, the heating efficiency will sharply decrease. That's why natural circulation if it can be considered, then only as an “emergency” one, but most often a closed system is planned and installed specifically for the use of a circulation pump.

Main elements of a closed heating system

So, the general closed-type heating system for a private house includes:

- heating device - boiler;

- circulation pump;

— pipe distribution system for coolant transfer;

— expansion compensation tank of sealed type;

- heating radiators installed in the premises of the house, or other heat transfer devices (“warm floors” or convectors);

- safety group - valve system and air vents;

— necessary shut-off valves;

- in some cases - additional automatic monitoring and control devices that optimize the operation of the system.

Heating boiler

• The most common are . If a gas main is connected to the house or there is a real possibility of laying one, then most owners have no alternative but to give preference to this method of heating the coolant.

Gas boilers — optimal solution, if it is possible to install them

Gas boilers are distinguished by high efficiency, ease of operation, reliability and cost-effectiveness in terms of energy costs. Their disadvantage is the need to coordinate the installation project with the relevant organizations, since such a heating system is subject to very special safety requirements.

The variety of gas boilers is very large - you can choose floor-standing or wall model, with one or two circuits, simple in design or rich in electronics, requiring connection to a stationary chimney or equipped with a coaxial combustion product removal system.

• They are usually installed in conditions where gas supply to the house is impossible for some reason. Such an installation will not require approval - the main thing is that the requirements for electrical safety and compliance of the boiler power with the capabilities are met electrical network. Such heating devices are compact, simple and easy to adjust.

Behind heating systems with electric boilers The reputation of being “uneconomical” has been firmly established due to the relatively high cost of electricity. This is only partly true - modern electric heating devices, thanks to new water heating technologies, have very high efficiency, and with reliable insulation of the house should not burden the budget too much.

In addition to the familiar boilers with heating elements (which are really not very economical), modern developments are actively used.

"Battery" of three electrode boilers

For example, they are widely used in which heating is carried out due to the flow alternating current directly through the coolant (however, this will require a specially selected chemical composition water in the system). Such boilers themselves are inexpensive, but there are certain problems with adjustment.

Induction boiler - unpretentious and very economical