Features of the heating system of the house. Closed-type heating in a private house Two-pipe schemes - ring and dead-end

20.06.2020

Among the life-supporting engineering systems of modern residential and industrial buildings water heating systems occupy a special position. They differ in design features their execution, architectural and construction requirements for placement and operation, technological features. In addition, they must meet certain sanitary and hygienic requirements. All together they form specific, specific requirements for the device, operation and maintenance of heating systems and devices.

Water heating systems - classification

Water heating systems modern buildings are classified according to the following criteria.

1. According to institutional features:

by appointment: for civil objects (residential and public buildings); industrial (industrial, agricultural); special purpose (vehicles, military and other objects);
by forms of ownership: state, collective, private;
according to the method of service: public service, self-service, mixed service.

2. According to technological requirements:

compliance with the requirements of thermodynamics;
standards of reliability and safety of the device and operation.

3. According to the requirements of architectural and building codes, rules and
standards:

on methods of thermal and hydraulic calculations;
by design features: by the method of coolant circulation (natural and forced circulation); at the location of the wiring (upper and lower distribution line); according to the method of connecting the wiring to the heating risers (with a dead-end or with a passing water movement, collector); according to the design features of the risers and the scheme for mounting heating devices to them (single-pipe and two-pipe systems, vertical, horizontal); by type of pipelines used (metal, non-metal); by type of coolants (water, antifreeze);
by power and type of heat generators and heat sources, method of connection: local heat generators on carbon fuel and electricity (boilers for apartments, houses, rooftops, block boilers) with a capacity of up to 3.0 MW; centralized heat sources (supplying it to heating systems from nuclear power plants, thermal power plants, IES, RTS, KTS through heating networks and local or central heating points) with a capacity of over 3.0 MW; heat generators on non-traditional (renewable) heat sources; through hydraulic connection with a centralized source of heat (direct connection, hydraulically isolated); according to the method of connecting heating systems at the heating point (4 options for the main schemes);
according to the method of automation and metering of consumed heat
according to certain sanitary and hygienic requirements.

The main elements and technological features of water heating systems

The main principle technological feature water heating systems, in contrast to single-flow (single-pipe) systems of water supply, gas supply and sanitation, is that, in accordance with the laws of thermodynamics water heating systems can be circulating, double-flow, two-pipe.

The main elements of the heating system include: a heat generator (heating boiler), a coolant (water or antifreeze), supply and return pipelines, a circulation pump (if the system is with forced circulation of the coolant), a safety group, expansion tank and heating appliances (radiators).

Heating systems - principle of operation

The principle of operation of the heating system is that the coolant heated in the heat generator (heating boiler) is pumped to the heating devices of the building through supply pipelines with a temperature of t 1 ºС. In heating appliances, heat is released and the coolant is cooled, and, accordingly, its temperature potential (heat content) is lowered. Cooled to a temperature of t2, °C, it enters the return pipelines, through which it returns to its original position again - to the heat generator for subsequent heating.

Thus, in heating systems, thermal cycles are constantly performed - the circulation of the coolant in the amount of G, kg / h, and useful work space heating systems at temperature difference t1 - t2, °C, heat in the amount of Q, J/h.

As you know, each coolant has its own heat capacity c, J / (kg - ° C). Water has a heat capacity c = 4.19 kJ / (kg - ° C), which means that to heat 1 kg of water by 1 ° C, it is necessary to spend 4.19 kJ of heat. Knowing the values of G, t1, t2, s, it is possible to determine the amount of heat Qnp given off by the coolant in the heating devices of the heated room for one hour or for some period of time z, h, according to the formulas:

Qpr \u003d G -s (t1 - t2), J / h (1)
Qpr \u003d G -s (t1 -t2) -z, J. (2)

At the same time, to maintain a constant air temperature inside the room t pump \u003d Const, this amount of heat Q pr must correspond to the heat loss of the room (building) - Q pom, equal to the sum of heat losses through the external enclosing structures of the room (external walls, doors and windows, floors and ceilings), called transmission - Q transm, and heat consumption for heating the incoming outdoor ventilation air - Q vent, and in industrial buildings, in addition, for heating technological materials and products - Q tech, imported from the street.

The heat balance must be observed:

Q pom \u003d Q pr \u003d Q transm + Q vent + O tech, J / h (3)

V last years they also began to take into account internal heat gains - heat releases: from people in the premises, from household electrical and cooking appliances, from technological devices, from finished products and products, from solar radiation, etc. These heat releases Q tvn, J / h, reduce the need for a room (building) in the heat that it must receive from the heating system. The heat balance of the room, taking into account internal heat release, will look like this:

Q pom \u003d Q pr \u003d Q transm + Q vent + O tech - Q tvn, J / h (4)

To effectively fill the water heating system with a coolant (usually water) and keep the circulation ring in a filled state, as well as to empty the system, three more mandatory elements are required - a make-up device (pump), a descent device and an expansion tank.

With the help of a make-up device, the entire system, including a heat supply source, a circulation pump, supply and return lines of pipelines (supply and return), all heating devices located in the room, as well as an expansion tank, are slowly (through a return line) filled with coolant (water). In the process of filling or replenishing the system, the coolant displaces air from the internal cavities of pipelines and heaters upwards, into an expansion tank or into special, so-called air vents. In some U-shaped heating systems, air vents (Maevsky taps) are installed in the upper plugs of heating appliances.

If it was not possible to completely remove the air from the system, then air plugs are formed that break the coolant flow in pipelines and heating devices and prevent its circulation in the system. Often there are cases of emergency failure of systems due to a violation of the circulation regime (heat carrier overheating due to air locks). For effective air removal, the supply lines of the pipelines are installed with a slight slope (i = 0.010) in the direction from the main riser towards the heating devices, and the pipelines performing the return supply - with the same slope from the heating devices towards the heating source (heat generator) to the drain valve.

When the coolant is heated, gases dissolved in cold water - oxygen, nitrogen and carbon dioxide - are released from it in the form of bubbles, which are removed from the system in the same way (through an expansion tank or air vents) during its operation.

The laying of distributing pipelines with a slope also allows you to quickly remove the coolant in cases of emptying them for repair purposes, and prevents the coolant from “hanging” in the pipes.

An expansion tank with a volume of V (m3) is mounted at the highest point of the system (usually an attic room), and must be insulated. It is a kind of buffer for the heating system, and with its volume it allows to compensate for changes in the volume of the circulating coolant - an increase during heating and a decrease during cooling, as well as to compensate for its small loss due to evaporation and possible leaks through system leaks. An open expansion tank equipped with signal and overflow pipes allows personnel to periodically control the filling of the system with coolant (water), fill and replenish it with a make-up device if necessary.

In small house and cottage heating systems, such filling and make-up is carried out from the drinking water supply by opening a tap on the make-up line. In the absence of a water supply system, it is carried out either with the help of an electric or manual pump connected to an intermediate, periodically replenished with water when the tank is pumped. In water heating systems of large multi-storey buildings, special make-up pumps are installed for these purposes and make-up is carried out with specially prepared softened and deaerated water to prevent corrosion and overgrowth of metal pipelines.

At the lowest point of the heating system on the return line of the pipeline (return), a drain valve is installed, with the help of which the coolant (water) is drained from the system, in cases of repair work or long shutdowns to avoid freezing during the winter. To avoid "hanging" of the coolant in the pipelines and heating devices during the descent, it is necessary to open the air vents installed at the upper points of the system.

The circulation pump of the heating system is installed, as a rule, on the pipeline that performs the return flow (return) in front of the heating source (heat generator). In large branched heating systems of buildings, several (2-3) circulation pumps (one standby) are usually installed.

All the mentioned mandatory elements of water heating systems - a heat generator, a circulation pump, heaters, an expansion tank, air vents and a make-up device, instrumentation and control devices are interconnected by pipelines in a certain sequence and order, forming a complex hydraulic circulation system - a system of closed communicating vessels and rings filled with coolant.

Heating of a private house
Expansion tank
Circulation pump

On the territory of our state, the most popular type of home heating is water heating, as the traditional and most rational option. Its high popularity is due to the relatively affordable price of the materials from which the system is assembled, and the fuel, the role of which in most cases is played by natural gas.

How does it function?

The principle of operation of water heating is remarkable for its simplicity. Such heating is characterized by a closed system, the main elements of which are pipes, radiators and a heating boiler.
The heat generator heats up the coolant (water, glycol solution), which, in turn, flows through pipes to radiators installed in heated rooms.

Hot batteries heat up the air due to heat transfer, and a comfortable temperature. After cooling, the liquid returns to the boiler, where its temperature rises, and the cycle repeats again and again.

Circulation type

As mentioned earlier, water heating functions due to the movement of the coolant through the system. We will now consider existing species water circulation, which have fundamental differences that must be taken into account when choosing a scheme.

Natural (gravitational)

In this case, the heating process consists in different densities of hot and cold coolant.

The heated liquid loses its density and decreases in weight, therefore it is pushed upwards, flowing through the pipeline. Having given off heat and lowering the temperature, the water becomes denser, sinks down and goes back to the boiler.

The advantages of a natural water heating system include its autonomy, since it does not need electricity, and a very simple design.

If we talk about the shortcomings, then an impressive number of pipes with a large diameter will be required here, otherwise the gravity process will be disrupted, and modern radiators with a small cross section will simply not be able to dock with the main. Also, when installing the pipeline, it is necessary to ensure a slope of 2 °, which will contribute to the correct operation of the system.

Forced

The flow of water through the pipeline occurs with the help of circulation pump. The excess mass of the coolant, which is formed after heating, is discharged into the expansion tank (in most cases, a closed design), which prevents the liquid from evaporating.

This rule especially applies when glycol compounds are used as a heat transfer medium. The pressure in forced heating systems must be monitored using a pressure gauge.

The advantages of such a water heating system are very obvious and consist in a small volume of coolant with a low consumption of pipes, the diameter of which is inferior to the previous version.

Also here it becomes possible to set the desired temperature for heating radiators, which can be absolutely any type. The disadvantage is the dependence on the supply of electricity, without which the operation of the pump is impossible.

Equipment

Water heating will be reliable and efficient only if all its parts are correctly selected and the installation is done correctly. In this case, the elements of the system must interact with each other and match each other by type.

Boiler

The choice of the main heater is determined by the fuel that will be used to heat the house. According to their type, boilers are:

gas;
electric;
liquid and solid fuel;
combined.

Natural gas-powered devices are rightfully considered the most economical, but they require a pipeline and constant monitoring by special services.

Complete independence from the central energy system can be achieved using solid or liquid fuels, but you will have to come to terms with the concerns of harvesting and storing energy resources.

The electric boiler is the least in demand, as it consumes a lot of energy and, as a result, entails high heating costs. In this case, it is better to install radiators that directly convert electricity into heat.

The power of the unit is selected according to the area of \u200b\u200bthe room that will be heated using a water heating system. The selection is made at an average ratio of 1 kW: 10 m², while the height of the walls should be no more than 3 m. You also need to take into account the degree of thermal insulation of the room, the size of the window frames and the presence of third-party heat consumption points.

Highways

Traditional pipes for the circuit, which are easily corroded, are increasingly giving way to products that do not have such a significant drawback. They were replaced by samples of galvanized metals and stainless steel.

The most reliable option is considered to be copper parts that are resistant to a sharp drop in pressure and temperature. They do not rust and easily hide in the wall. Their only drawback is the high cost of the material, which is considered a representative of the premium segment.

Pipes from metalplastic differ in the long term of operation. They have excellent strength, are resistant to corrosion, do not accumulate sediments on the inner walls, their installation is simple, and installation work is carried out quickly.

The disadvantage is the high coefficient of linear expansion with temperature changes, which can lead to damage.

Wiring

Water heating of a private house can be mounted in different ways, depending on what types of functions are assigned to it. There are two schemes:

Single-circuit.
Dual circuit.

One circuit

The first type is designed only for space heating. It includes a single-circuit boiler with air exhaust, single-pipe wiring and batteries with the required number of sections.

To ensure the supply hot water, which is used for household needs, you can install two such structures at the same time. So, one of them will heat the house, and the second will be responsible exclusively for the hot water supply. This practical solution, since in the warm season it makes no sense to heat the home for the sake of getting warm water shower or kitchen.

This design is very easy to assemble and affordable. It is suitable for houses with a small area (up to 100 m²). This explains its popularity among owners of small cottages. Single-circuit water heating can be improved by installing a circulation pump, battery-powered temperature controllers and two-pipe wiring.

Two circuits

This principle of wiring provides for the simultaneous supply of hot water and heating of the area. Suitable for houses where no more than 4 people live.

It should be borne in mind that tap or softened water is suitable here. Hard fluid from the well can damage the equipment of the system and therefore cannot be used.

System type

Having familiarized yourself with the methods of circulation of the coolant through the mains, it is worth knowing that the circuit of the water heating system can be single-pipe, two-pipe and manifold. Let's consider all three options in more detail.

One pipe

In this case, water sequentially moves from radiator to radiator, while losing temperature along the way, which makes each subsequent battery colder.

This negatively affects the achievement of a comfortable climate in the rooms.

two pipes

Such a scheme is characterized by better heating of the premises. It provides for the installation of two pipes that are connected to each radiator. One of them supplies the batteries with hot coolant, and the second takes the cooled water back to the boiler, so heat loss will be minimal.

Most effective option, in which a mandatory element is a collector, separately supplying a pipe with hot water for each heating element. Another pipe returns the cooled coolant back.

Given this feature, it is possible to carry out repairs and set the temperature of each radiator separately without decommissioning the entire circuit. Unfortunately, here the consumption of pipes increases significantly and it becomes necessary to carry out work on the installation of a manifold cabinet.

Distinctive characteristics

If we compare with air and electric heating, then water heating has firmly taken a leading position due to many factors. First of all, this is an affordable price for materials, work and operation of the system, including payment for the spent energy resource, which other types of home heating cannot boast of.

Here we can note the high heat transfer of the heating elements, which contributes to the uniform heating of the rooms and the establishment of a comfortable climate. Also important is the fact that the coolant can be heated using any type of fuel, which is impossible with electric heating.

All work on installing a water system is easily done by hand and this is also a huge plus. With air routes, things are more complicated and, most likely, you will have to seek help from specialists.

This guide is intended for owners of small private houses seeking to independently organize the heating of their homes in order to save money. The most rational solution for such buildings is a closed heating system (abbreviated as ZSO), which operates with an excess pressure of the coolant. Consider its principle of operation, varieties of wiring diagrams and a do-it-yourself device.

The principle of operation of closed CO

A closed (otherwise - closed) heating system is a network of pipelines and heating devices in which the coolant is completely isolated from the atmosphere and moves forcibly - from the circulation pump. Any SSO must include the following elements:

heating unit - gas, solid fuel or electric boiler;
safety group consisting of a pressure gauge, safety and air valve;
heating devices - radiators or contours of underfloor heating;
connecting pipelines;
a pump that pumps water or non-freezing liquid through pipes and batteries;
coarse mesh filter (mud collector);
closed expansion tank equipped with a membrane (rubber "pear");
stopcocks, balancing valves.

Typical scheme of a closed thermal

Note. Depending on the scheme, the ZSO additionally includes modern devices for controlling the temperature and flow of the coolant - radiator thermal heads, check and three-way valves, thermostats, and the like.

System operation algorithm closed type with forced circulation looks like this:

After assembly and pressure testing, the pipeline network is filled with water until the pressure gauge shows a minimum pressure of 1 bar.
The automatic air vent of the safety group releases air from the system during filling. He is also engaged in the removal of gases that accumulate in pipes during operation.
The next step is to turn on the pump, start the boiler and warm up the coolant.
As a result of heating, the pressure inside the SSS increases to 1.5-2 Bar.
The increase in the volume of hot water is compensated by a membrane expansion tank.
If the pressure rises above the critical point (typically 3 bar), safety valve will flush out excess fluid.
Once every 1-2 years, the system must undergo an emptying and flushing procedure.

The principle of operation of the ZSO of an apartment building is absolutely identical - the movement of the coolant through pipes and radiators is provided by network pumps located in an industrial boiler room. There are also expansion tanks, the temperature is controlled by a mixing or elevator unit.

How a closed heating system works is explained in the video:

Positive qualities and disadvantages

The main differences between closed heat supply networks and outdated open systems with natural circulation– lack of contact with the atmosphere and the use of transfer pumps. This gives rise to a number of advantages:

the required pipe diameters are reduced by 2-3 times;
the slopes of the highways are made minimal, since they serve to drain water for the purpose of flushing or repair;
the coolant is not lost by evaporation from an open tank, respectively, you can safely fill pipelines and batteries with antifreeze;
ZSO is more economical in terms of heating efficiency and cost of materials;
closed heating lends itself better to regulation and automation, can operate in conjunction with solar collectors;
forced flow of the coolant allows you to organize floor heating with pipes embedded inside the screed or in the furrows of the walls.

The gravitational (gravity-flowing) open system outperforms the ZSO in terms of energy independence - the latter is unable to operate normally without a circulation pump. Moment two: a closed network contains much less water and in case of overheating, for example, a TT boiler, there is a high probability of boiling and the formation of a vapor lock.

Reference. A wood-burning boiler saves from boiling, plus a buffer tank that absorbs excess heat.

Types of closed systems

Before you buy heating equipment, pipe fittings and materials, you need to choose the preferred option for a closed water system. Master plumbers practice the installation of four main schemes:

Single-pipe with vertical and horizontal wiring (Leningradka).
Collector, otherwise - beam.
Two-pipe dead-end with shoulders of the same or different lengths.
Tichelman's loop - ring wiring with associated water movement.

Additional Information. Closed heating systems also include water heated floors. it is much more difficult to assemble radiator heating; it is not recommended for beginners to undertake such installation.

We propose to consider each scheme separately, analyzing the pros and cons. As an example, let's take a project of a one-story private house with an area of 100 m² with an attached boiler room, whose layout is shown in the drawing. The value of the heat load for heating has already been calculated, the required amount of heat is indicated for each room.

Installation of wiring elements and connection to a heat source is approximately the same. The installation of a circulation pump is usually provided in the return line, a sump is mounted in front of it, a make-up pipe with a tap and (if you look downstream). Typical piping of solid fuel and gas boiler presented in the diagrams.

The expansion tank is conditionally not shown in the figure

Read more about installation and connection methods for heating units using various energy carriers in separate manuals:

Single pipe wiring

The popular horizontal scheme "Leningradka" is one ring main of increased diameter, where all heating devices are connected. Passing through the pipe, the heated coolant flow is divided at each tee and flows into the battery, as shown in the sketch below.

Having reached the branch, the flow is divided into 2 parts, about a third flows into the radiator, where it cools and returns to the main line again

Having transferred heat to the room, the cooled water returns to the main, mixes with the main flow and moves to the next radiator. Accordingly, the second heater receives water cooled by 1-3 degrees, and again takes away the required amount of heat from it.

Leningrad horizontal wiring - one ring line bypasses all heating devices

The result: colder water enters each successive radiator. This imposes certain restrictions on a closed one-pipe system:

The heat transfer of the third, fourth and subsequent batteries must be calculated with a margin of 10-30% by adding additional sections.
The minimum line diameter is DN20 (internal). Outer size PPR pipes will be 32 mm, metal-plastic and cross-linked polyethylene - 26 mm.
The section of the inlet pipes to the heaters is DN10, outside diameter- 20 and 16 mm for PPR and PEX, respectively.
The maximum number of heaters in one Leningradka ring is 6 pcs. If you take more, there will be problems with increasing the number of sections of the last radiators and increasing the diameter of the distribution pipe.
The cross section of the ring pipeline does not decrease throughout its entire length.

Reference. Single-pipe wiring is vertical - with lower or upper distribution of the coolant through the risers. Similar systems are used to organize gravity flow in two-story private cottages or work under pressure in apartment buildings old building.

A closed-type single-pipe heating system will be inexpensive if it is soldered from polypropylene. In other cases, it will decently hit your pocket due to the price of the main pipe and fittings (tees) of large sizes. What the "Leningradka" looks like in our one-story house is shown in the drawing.

Since the total number of heaters exceeds 6, the system is divided into 2 rings with a common return manifold. The inconvenience of installing single-pipe wiring is noticeable - you have to cross doorways. A decrease in the flow in one radiator causes a change in the water flow in the remaining batteries, so the balancing of the "Leningrad" is to coordinate the operation of all heaters.

Advantages of the beam scheme

Why the collector system received such a name can be clearly seen in the presented diagram. From the comb installed in the center of the building, individual coolant supply lines diverge to each heating device. Eyeliners are laid in the form of rays along the shortest path - under the floors.

The collector of a closed beam system is fed directly from the boiler, circulation in all circuits is provided by a single pump located in the furnace. In order to protect the branches from airing during the filling process, automatic valves - air vents are installed on the comb.

Strengths of the collector system:

the scheme is energy efficient, since it allows you to clearly dose the amount of coolant sent to each radiator;
the heating network is easy to fit into any interior - the supply pipes can be hidden in the floor, walls or behind a suspended (stretch) ceiling;
hydraulic balancing of the branches is carried out using manual valves and flow meters (rotameters) installed on the manifold;
all batteries are supplied with water of the same temperature;
the operation of the circuit is easy to automate - the manifold control valves are equipped with servo drives that close the flow at the signal of the temperature controllers;
ZSO of this type is suitable for cottages of any size and number of storeys - a separate collector is installed at each level of the building, distributing heat to groups of batteries.

In terms of financial investments, closed beam system not too expensive. A lot of pipes are consumed, but their diameter is minimal - 16 x 2 mm (DN10). Instead of a factory comb, it is quite allowed to use soldered from polypropylene tees or twisted from steel fittings. True, without rotameters, the adjustment of the heating network will have to be done using radiator balancing valves.

The distribution manifold is placed in the center of the building, the radiator lines are laid directly

There are few cons of beam wiring, but they are worth attention:

Concealed installation and testing of pipelines is carried out only at the stage of new construction or major repairs. Laying radiator hoses in the floors of a lived-in house or apartment is unrealistic.
The collector is highly desirable to be located in the center of the building, as shown in the drawing one-story house. The goal is to make the leads to the batteries approximately the same length.
In the event of a leak in a pipe embedded in a floor screed, it is quite difficult to find the defect without a thermal imager. Do not make connections in the screed, otherwise you risk running into the problem shown in the photo.

Joint leak inside concrete monolith

Two-pipe options

On device autonomous heating apartments and country houses 2 types of such schemes are used:

Dead end (another name is shoulder). Heated water is distributed to heating devices through one line, and is collected and flows back to the boiler through the second line.
The Tichelman loop (associated wiring) is a ring two-pipe network, where the heated and cooled coolant moves in the same direction. The principle of operation is similar - the batteries receive hot water from one line, and the cooled water is discharged into the second pipeline - the return line.

Note. In a closed passing system, the return line starts from the first radiator, and the supply line ends at the last one. The diagram below will help you figure it out.

What is good dead-end closed heating system of a private house:

the number of "shoulders" - dead-end branches - is limited only by the capacity of the boiler plant, so two-pipe wiring is suitable for any building;
pipes are laid in an open or closed way inside building structures - at the request of the homeowner;
as in the beam scheme, equally hot water comes to all batteries;
ZSO lends itself perfectly to regulation, automation and balancing;
correctly laid out "shoulders" do not cross doorways;
at the cost of materials and installation, a dead-end wiring will cost less than a single-pipe one if the assembly is carried out with metal-plastic or polyethylene pipes.

The best option for connecting batteries - two separate branches go around the premises on both sides

Designing a closed shoulder system for a country or residential building with an area of up to 200 square meters is not particularly difficult. Even if you make branches of different lengths, the circuit can be balanced by deep balancing. An example of wiring in a one-story building of 100 m² with two "shoulders" is shown above in the drawing.

Advice. When choosing the length of the branches, the heating load must be taken into account. The optimal number of batteries on each "shoulder" is from 4 to 6 pcs.

Connection of heaters with passing movement of the heat carrier

The Tichelman loop is an alternative closed two-pipe network that combines a large number heating appliances (over 6 pcs.) in a single ring. Take a look at the associated wiring diagram and pay attention: no matter what radiator the coolant flows through, the total length of the route will not change.

From here, an almost ideal hydraulic balance of the system arises - the resistance of all sections of the network is the same. This significant advantage of the Tichelman loop over other closed wiring also entails the main drawback - 2 highways will inevitably cross the doorway. Bypass options - under the floors and above the door jamb with the installation of automatic air vents.

Disadvantage - the ring loop passes through the opening of the front door

Choosing a heating scheme for a country house

Dead-end two-pipe.
Collector.
Two-pipe passing.
Single pipe.

Hence the advice: you will not be mistaken if you choose the first option for a house up to 200 m² - a dead-end scheme, it will work in any case. Beam wiring is inferior to it in two respects - the price and the possibility of installation in rooms with a finished finish.

A single-pipe version of the heating network is perfect for small house with a square of each floor up to 70 m². The Tichelman loop is appropriate for long branches that do not cross doors, for example, heating the upper floors of a building. How to choose the right system for houses various shapes and number of storeys, look at the video:

Regarding the selection of pipe diameters and installation, we will give a few recommendations:

If the area of \u200b\u200bthe dwelling does not exceed 200 m², it is not necessary to make calculations - use the advice of an expert on the video or take the cross section of pipelines according to the diagrams above.
When you need to “hang” more than six radiators on a dead-end wiring branch, increase the pipe diameter by 1 standard size - instead of DN15 (20 x 2 mm), take DN20 (25 x 2.5 mm) and lay up to the fifth battery. Then lead the lines with a smaller section indicated initially (DN15).
In a building under construction, it is better to do beam wiring and choose radiators with a bottom connection. Underground highways must be insulated and protected with plastic corrugation at the intersection of the walls.
If you don’t know how to properly solder polypropylene, then it’s better not to mess with PPR pipes. Mount heating from cross-linked polyethylene or metal-plastic on compression or press fittings.
Do not lay pipe joints in walls or screed, so as not to have problems with leaks in the future.

If you need to heat several rooms at once, then one of the solutions with which this can be realized is water heating. Although now there are many types of space heating, but this traditional method is the most practical, common and affordable.

Types of water heating

During the operation of this type of heating, water is heated, which moves through the pipes and heats the premises.

There are several types of such systems:

with natural circulation. In this case, the operation of the system occurs due to the different density of cold and hot water. Heating is carried out from below and, according to the laws of physics, there is a natural circulation of water through the pipes.

With forced circulation. In this system, it is used to move the coolant.

Combined system. Here, the two previous options are used simultaneously.

In addition, water heating may differ in the pipe installation scheme:

Single pipe or single-circuit, here the coolant moves through the pipes in series, so the temperature in the radiators located closer to the boiler will be higher than those that are further away.

Two-pipe, it makes it easier to regulate the temperature and, in turn, can be: star-shaped, loop, collector.

To heat water in such a heating system, boilers are used that run on fuel:

Solid (coal, briquettes).
Liquid (diesel fuel).
Electricity.
Combined devices.

System device

The device of the water heating system is quite simple, but it works efficiently, which explains the popularity of this heating method.

Water heating consists of the main elements:

Boiler, it is used to heat water or antifreeze.
Expansion tank, during heating, the water expands and it needs to go somewhere.
Pipe system, they can be steel, copper, metal-plastic or plastic, they create a closed heating circuit.
Devices that give off heat to the room - these can be ordinary steel or bimetallic, etc. radiators, but now they often install underfloor heating.
The pump, it is necessary for pumping water through the system.
Thermometer and pressure gauge, these devices are necessary to control the temperature and pressure of the liquid in the system, they can be built into the boiler or installed separately.

Operating principle

Some people call water heating steam, but this is wrong. Steam heating is a separate type of heating, in which steam acts as a heat carrier, and in our case, water or another liquid heat carrier.

Regardless of the type, the principle of operation of such heating will be the same. During the operation of the heating device, water or other coolant is heated in it. After that, due to forced or natural circulation, the heated coolant begins to circulate through the pipes and heats the rooms. Heat can be released into the room, both through radiators and through the floor heating system. Through the pipe system, the cooled coolant returns to the heating device, and the whole process is repeated again.

Application area

Water heating is used both for heating multi-storey and private houses. In addition, it is used for heating offices, shops, industrial enterprises. This solution allows you to significantly save the fuel used - it is electricity, coal or gas, etc.

This method of heating is most often used in residential areas where people are constantly. This is due to the fact that it provides a comfortable temperature change mode, since there are no sharp jumps during the operation of the system. In addition, water or antifreeze has a high heat capacity, which allows them to cool for a long time and maintain heat even when the boiler is not working.

Do not think that water heating is an ideal heating system. The installation of such a system is quite complicated, so if you do not have the appropriate skills, then you will not be able to do it yourself. It is necessary to control the operation of the boiler so that it does not die out, with the exception of electric boilers where this process is automated.

When the system is not used for a long time, it is recommended to drain the water from it, especially in winter, otherwise pipes and radiators can be defrosted. It is necessary to control that air pockets do not form in pipes or radiators, as corrosion appears in these places.

If such a system is made by professionals and is properly operated, then it is able to maintain a comfortable temperature for living in any room.

Features of choice

When choosing this home heating system, you first need to decide on the source that will heat the coolant. If the house has main gas pipeline, then it is better to use a gas boiler. A good alternative is an electric boiler, but you can also install solid fuel equipment or something that runs on liquid fuel. It all depends on which energy source will be the cheapest and most affordable in your area. You can connect several heat generators in parallel, which will work in turn, depending on the availability of one or another type of fuel.

When choosing a circulation system, and it can be natural or forced, you must take into account your requirements for the heating system and what financial capabilities you have. If water is heated in a solid fuel boiler or furnace with a water circuit, then natural circulation of the coolant is often used. When using gas or electric heating, it is better to use a forced circulation system of water or antifreeze.

When choosing pipes, there are several options: metal, plastic and metal-plastic. For natural circulation, pipes must be mounted with a slope, metal pipes are better suited for this, but you need to have special skills to install them. metal-plastic and plastic pipes can also be laid with a slope, but they are not designed for temperatures over 95 degrees, so they are usually used to create systems with forced circulation.

To connect metal-plastic pipes, special couplings are used, so their laying is easy to do with your own hands. To install plastic pipes, you need to purchase a special soldering iron, it is inexpensive, and it is easy to work with it.

When choosing a radiator, it is necessary to take into account the way it is connected, it can be from above, below, from one or different sides.

Advantages and disadvantages

The most commonly used water heating with forced or natural circulation, consider their advantages and disadvantages.

Advantages of a system with forced circulation of water or antifreeze:

You can automatically control the flow of heat from the radiators and thus set the temperature in each room separately.
It is more economical, since the ability to control the temperature in each room separately leads to a reduction in the energy required to heat the water in the system.
It is possible to use plastic pipes, and this allows you to speed up the installation of the entire system and reduce the cost of materials.
Plastic pipes are hidden in the wall or placed above the plinth, so they do not spoil appearance rooms.

The main disadvantage of such a heating system is that it requires electricity to operate, otherwise the pump will not work.

If we talk about the natural circulation of the coolant, then such a heating system is completely autonomous, since electricity is not needed for its operation.

Disadvantages of a heating system with natural water circulation:

Radiators cannot regulate the temperature of the water.
Fuel overrun.
Pipes need to be installed. large diameter, and this increases the cost of such a heating system.
Pipes placed on the walls do not look very attractive.
This heating system is not compatible with underfloor heating.

Although there are many ways to heat a house, water heating has remained the most efficient, practical and affordable for many years. Modern industry periodically introduces new or improved heat generators, pipelines and generators, due to which the efficiency of this heating method increases and its cost decreases.

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 during various modes work. By design, expansion tanks are open and closed, respectively, and heating systems are called open and closed.

In recent years, it is the closed heating circuit that has become increasingly popular. Firstly, it is automated and works without human intervention. 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). Tank open type should stand 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 it is possible to organize, but it is difficult - flow regulation 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 install uninterruptible power supplies with batteries and / or small generators that will 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. The first is that a safety group is built into the boiler (gas wall-mounted boilers, pellet boilers 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 a 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 time- 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. Important point: for installation of an oil-fired boiler, it is obligatory separate room 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 equipment periodical action(they warm up during the fire, cool down when the bookmark burns out), but 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). With good fuel quality, 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. It consists of a pressure gauge, an automatic air vent and a 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. A very convenient device that 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. At the top 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 designed for cold water and do not tolerate high temperatures.

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 put a 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, as an additional element of reliability, another is placed between the filter and the ball valve. 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 hand pump hose is connected to the ball valve. 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 a two-pipe system, this may be one of the last in the radiator branch, 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