Steam heating in a private home and country house based on a stove or boiler

Efficient home heating is one of the most important tasks for every homeowner.An interesting solution to this problem could be a steam heating system, the operating principles and design of which differ from the usual water circuits.

This is not the easiest option, and has its own strengths and weaknesses. We will talk about the rules of design and organization, the features of the system with a vapor coolant. You will learn how to install steam heating in a private home and how to operate it correctly.

Operating principle of the steam system

When water boils at constant pressure, it maintains its temperature constant. The steam formed as a result of such boiling has a significant amount of thermal energy. At the moment of condensation, i.e. When steam turns into liquid, this energy is released and transferred to the environment.

This principle is used in the operation of steam heating systems. Water boils in the boiler, steam moves through the pipes to the radiators, where it condenses and dissolves with heat, thereby heating the air in the room.

The water obtained during the condensation process continues to move through the pipes and returns to a special storage tank, and then flows to the heater naturally or forcibly using a pump.

Depending on the pressure inside the steam heating system, they are divided into:

• vacuum-steam;
• low pressure;
• high pressure.

In the first, the pressure is less than 0.1 MPa, in the second - even lower - up to 0.07 MPa, and in the third - more than 0.07 MPa. Open low-pressure systems have access to air from the atmosphere, but they can also be closed, i.e. completely sealed.

This diagram demonstrates the principles of steam heating wiring. The heating device should be located lower than the radiators; the condensate line should be sloped

Such systems usually use so-called dry saturated steam, which does not contain suspended water particles. The amount of steam in the system affects its operation. If there is too little steam, it will create problems for the free flow of condensate, and cold air will collect at the bottom of the heating device.

A sufficient volume of steam improves the process of outflow of condensate, which is pushed towards the walls and flows down them in the form of a thin film of water.

In closed systems, water immediately enters the heat exchanger after condensation, but open-loop systems are often used in which the coolant is first collected in a storage tank and then pumped into the boiler for heating.

Condensate can completely fill the pipes through which it moves for heating or only partially. The latter option is preferable, since when the system is turned off, the pipes in it will remain dry.

If the steam heating coolant, after condensation, moves directly into the boiler for subsequent heating, the system is called closed.If condensate is first collected in a storage tank, from which it is pumped into the boiler by a pump, the system is classified as open

Features of low pressure systems

A common version of such a system is closed, using gravity return of condensate to the boiler, which does not completely fill the pipes, and an upper pipe distribution is used.

First, the system is filled with water to the required level, after which heating begins. The condensate flows down a common riser and, when a predetermined level is reached, is forced into the boiler.

In the same system with bottom distribution, it is recommended to install pipes with a slight slope in the direction of steam movement in order to reduce noise effects. At the point where the condensate is drained, a loop-shaped water seal is installed, which prevents the movement of steam onto the condensation line.

The steam velocity in such systems should be moderate, no more than 0.14 m/s. Otherwise, the steam will also capture particles of moisture accumulated on the walls. As a result, the system operates with more noise and increases the risk of water hammer.

Combined wiring, i.e. a combination of upper and lower wiring is used if pipes are laid under the floor of the upper or middle floor of the house. The lumen of the pipes through which water returns to the boiler will in this case be closed by condensate.

If the pressure in the system exceeds 0.02 MPa, it should be made open. The air is removed through a condensate storage tank, and to prevent steam from leaving the system, a condensate drain or water seal is installed. Water from the storage tank is pumped into the heat exchanger, which allows the storage tank to be installed below the level at which the heat exchanger is located.

The coolant for heating a private house with a boiler room is heated in a heat exchanger located in the boiler room. Upon reaching the operating temperature, the steam moves to a manifold that divides the flow into two circuits: for the main rooms and for the boiler room (+)

Assessing advantages and disadvantages

What are the benefits of a steam heating system? It is relatively easy to make even on the basis of a conventional wood stove. This is especially true in areas where there is no centralized gas supply, but firewood or other solid fuel is quite accessible.

Steam is significantly ahead of water as a coolant. Its heating rate is three times higher. In addition, a steam heating system is unlikely to fail during winter cold due to lack of heating.

If the firebox burns out, water from the system will collect in the storage tank or heat exchanger, and the pipes and radiators will remain empty. With water heating, freezing of the coolant, which fills the entire circuit, is known to lead to pipe rupture.

Finally, the dimensions of steam heating radiators should be significantly smaller than for water systems, since the amount of thermal energy obtained as a result increases several times. This will slightly reduce the cost of installing a heating system at home.

Decorative grilles for steam heating radiators are not only an element of interior design, but also a means of protection against burns

This concludes the list of advantages of the steam system, and we can move on to its disadvantages, which are quite significant:

• high risk of burns;
• increased noise level during operation;
• difficulties in adjusting the operation of the system;
• the need to purchase expensive pipes, etc.

Safety standards do not recommend steam heating for residential premises, as it poses a high risk to the health and life of people living in the house.

Thus, the operating temperature of the radiators will be very high, and if you touch them you can get a serious burn. Therefore, all radiators will have to be covered with reliable decorative grilles.

Ordinary PVC pipes are not suitable for such a system, since they must withstand high pressure and temperatures of more than 100 degrees. The same requirements apply to other elements of the system. Steam heating pipes must be copper or galvanized steel.

Copper pipes are an ideal, but not at all cheap, communication option for steam heating systems. To connect these pipes you will need a welding machine

In any case, this moment cannot be called budgetary. Security issues must be given the utmost attention. All installation work, for example, welding copper pipes, will require the highest quality performance. If the connection ruptures and a stream of steam escapes through the hole, one of the occupants of the house risks serious burns.

Stainless steel pipes are able to withstand the loads typical of steam heating systems, such as high temperature and increased pressure in the system

Another disadvantage of steam heating is the increased noise level. To fix this problem, you must install the radiators correctly. They are suspended on special anti-noise brackets. It is best to place the boiler or stove in a separate room. In addition, copper pipes can be placed in the thickness of the walls, which will also reduce the noise level.

Finally, it is a little difficult to regulate the heating temperature in rooms with steam heating. You cannot install a thermostat and simply reduce the amount of steam. You will have to reduce the amount of fuel, which is not always easy, or ventilate the premises. Before starting work on installing a steam heating system, all these points should be taken into account.

Design of a steam heating system

Even for a small room, it is best to draw up a project. A system made at random will most likely soon require rework, and a diagram drawn up on paper will allow you to immediately identify weak points and correct them.

For example, in order to create a system with natural coolant circulation, the heat exchanger, and accordingly the heating device, should be located at the lowest point of the house.

The steam and condensate pipelines of heating systems with a natural type of coolant movement are arranged with a slope in the direction of its movement (+)

This means that the stove or boiler must be located below all radiators, as well as pipes that are not vertical, but horizontal or at an angle to the vertical.

If it is not possible to place the heating device in this way (the house does not have a basement, the basement is used for other purposes, etc.), preference should be given to heating with forced circulation.

The diagram shows a heating system with forced circulation. To install it you will need a circulation pump and a storage tank.

Therefore in steam heating diagram it is necessary to turn on the pump that will pump water into the heat exchanger. An important point in designing a heating system is the order in which the radiators are connected.A sequential connection or the so-called one-pipe system involves connecting all radiators in order.

As a result, the coolant will sequentially move through the system, gradually cooling down. This is an economical connection option, which is easier to install and will be cheaper.

But the uniformity of heating with this method will suffer, since the first radiator will be the hottest, and the last coolant will enter in a half-cooled state.

Single-pipe connection of radiators, as can be seen from this diagram, involves sequential installation. The coolant reaches the last radiator already cooled down

A single-pipe solution may only be acceptable when connecting steam heating in a country house or in a small house with an area of ​​less than 80 square meters. m. And for a spacious cottage or two-story building, a two-pipe system in which radiators are connected in parallel is more suitable.

The single-pipe design ensures simultaneous rather than sequential flow of coolant into each radiator, and the rooms are heated more evenly. But with a two-pipe circuit, two pipes will have to be connected to each radiator: direct and return.

Such a system is more difficult to implement, and it will cost a little more than when installing a single-pipe system. However, the vast majority of water heating systems are made according to a two-pipe scheme, despite the difficulties, and function quite successfully.

This diagram shows a two-pipe installation system for steam heating radiators. Each radiator is connected to a common riser and has a return pipe, which ensures uniform distribution of coolant

If you plan to use a wood stove as a heat source, you should immediately calculate and design a special heat exchanger. It looks like a coil welded from metal pipes. This element is built directly into the furnace structure, and is not installed separately.

Therefore, the design of a new furnace should also be considered at the design stage. You can also use an existing stove, but it will have to be partially disassembled in order to install the heat exchanger inside.

To obtain 9 kW of heat, a heat exchanger with a surface area of ​​about one square meter is required. The larger the heated area, the larger the size of the heat exchanger should be.

If you plan to heat the room using a boiler, then everything is a little simpler: you need to buy and install it. Usually, for steam heating in a house, it is recommended to take a water-tube boiler model, as it is the most efficient.

Although fire-tube, smoke-combustion or combined smoke-fire-tube models can also be a completely acceptable option.

Sometimes they use steam heating to organize homemade boiler, in which used engine oil is burned. But this option is considered suitable for use in utility rooms, for example, in a garage. For a residential building, this option is not very good.

Installation based on a wood stove

If the project has been drawn up, it’s time to stock up on the necessary materials and tools. A previously drawn up project will allow you to calculate the required number of system elements.

All turns, connections, tees, radiator installation locations, etc. should be marked on it. In addition, it is necessary to purchase pipe clamps, as well as brackets on which the radiators will be installed.

The boiler of the steam heating system, based on a wood-burning stove, is installed directly in it. A steam line and a condensate line are connected to the boiler

The length of the pipes is also calculated according to the diagram. To reduce the steam pressure in the system if necessary, you will need a pressure reducing valve. The hydraulic seal is required to allow the system to be completely drained for cleaning, maintenance or repair.

It is recommended to install a shut-off valve in front of each radiator, which will allow it to be turned off for repair, flushing or replacement. Also installed on radiators Mayevsky cranesto release any air trapped in the system. Although steam is a gaseous substance and not a liquid, the presence of air in the system can negatively affect its efficiency.

To ensure that the condensation process occurs in the radiators, and not in the storage tank or riser, it is recommended to install a tee with a plug at the outlet through which only water will pass. If you plan to install a system with forced circulation, you will need a circulation pump. In addition, you need a container to collect condensed moisture.

Gravity flow systems do not need such devices. But the pipe that carries the water to the heat exchanger must be wide enough to allow the liquid to move quickly for further heating.

The absence of a pressure reducing valve in the steam heating system, the device of which is shown in the diagram, can lead to serious damage due to excess pressure

In addition to the usual installation tools, you will definitely need a welding machine for copper pipe connections. Galvanized steel structures usually have threaded connections that must be carefully sealed. If you plan to install steam heating from a furnace, you will have to start with the manufacture of a heat exchanger.

A steam heating heat exchanger built into a wood stove consists of a system of hollow metal pipes through which water circulates. The element can have any shape corresponding to the size and shape of the oven

It is made from metal pipes 2.5-3 mm thick or even a little thicker. The heat exchanger can be made either in the form of a coil or in any other form. The main thing is that the device fits inside wood stove, and also that its surface is large enough to heat the water and generate steam.

The welding quality of the heat exchanger must be, without exaggeration, ideal. Even microscopic cavities in the seams are unacceptable, since the device will be exposed to increased pressure from hot steam. Once the heat exchanger is ready for installation, each weld should be checked.

To do this, first coat all seams with white chalk. After this, one of the heat exchanger holes is closed, and kerosene is poured into the second until the device is filled to the top. Now you need to wait a little and then evaluate the condition of the seams. If there are cracks, kerosene will seep through them, and in such places the chalk will darken.

Identified flaws are corrected, and then the test is repeated to ensure the integrity of the device. Now you should wash it, and then start laying the wood stove.The heat exchanger is securely built into the firebox, and pipes are connected to its inlet and outlet, which are then used to connect the heat exchanger to the heating system of the house.

The laying of the furnace is completed in the usual manner for such structures. Then the pipes are installed and heating system radiators in accordance with the project drawn up earlier. First, radiators are installed, using brackets that will dampen the noise from the operation of steam heating.

Mayevsky taps are installed on each radiator so that air can be released. You will need one more shut-off valves than radiators, since you need to install one common shut-off valve at the very beginning of the system. A pressure reducing valve and a reducing-cooling unit are also installed in front of this tap.

At the end, if provided for by the project, a coolant storage tank is installed and circulation pump. For systems designed with natural rather than forced circulation, a tank and pump are not needed. But the pipe that leads to the heat exchanger needs to be given a slight slope, about 3 mm per meter.

Modern boilers for steam heating in the house are reliable devices that operate on various fuels and are equipped with automated control systems

Systems with a steam boiler are installed in approximately the same way: in accordance with the design and adjusted for the features of the equipment. For example, a pressure reducing valve and a cooler will most likely not be needed since the steam pressure and temperature control system is already built into the boiler.

Some useful tips

When installing a steam heating system, you should remember that all its elements must withstand high temperatures, more than 100 degrees.For example, a regular membrane expander will not work as a reserve tank in case of an increase in coolant volume, because its maximum is 85 degrees.

The chimney of a stove with a built-in heat exchanger will become dirty faster than that of a conventional stove. That's why chimney cleaning needs to be planned and executed more often.

If desired, an oven with a heat exchanger can also be used for cooking, but this is not very convenient. In summer, when heating is not needed, this stove cannot be lit. We'll have to look for an alternative. It’s easier if there is a separate, convenient stove for the kitchen in the house.

How to design and assemble a steam heating system with your own hands is described in detail. In this article, which we recommend for reading.

Conclusions and useful video on the topic

Practical experience in converting a wood-burning stove into a steam heating boiler is presented in this video:

The continuation of the steam heating installation process can be viewed in this file:

The difference between forced and natural circulation in heating systems is described in detail here:

Steam heating is not the easiest option for an autonomous heating system to implement. But with proper design and installation, steam can be used to effectively and relatively inexpensively provide your home with the necessary amount of heat.

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