How to design heating in a two-story house. An effective heating system in a two-story house: scheme options

Air heating in residential buildings is a prerequisite for comfort. It is important to know how the heating scheme of a two-story house with forced circulation of the coolant works already at the design stage. This will help save money and supervise the construction crew. The builder's little skills will allow you to implement the heating system yourself.

Construction principles

Two-pipe heating system

Heating schemes in two-story houses are built on the basis of common structural elements.

The composition must include:

boiler-heat generator: electric, gas, solid or liquid fuel;
heat exchangers-radiators;
piping system from the boiler to the batteries;
automation and protection scheme;
expansion tank;
coolant;
adjusting equipment.

In modern gas and electric heaters, automation and an expansion tank are built into the structure. For solid-state heaters, a protective strapping is made.

Structural elements

Heating system elements

There are boilers on sale that can operate on two types of fuel - in the circuits of a gas or wood heater, in this case, electric tubular heaters (TENs) are built in.

Automatic heaters allow restarting heating after shutdown without user intervention or in manual mode. Protection circuits promptly turn off the supply of energy in emergency operating modes (overheating of the coolant, overpressure in the system). Such devices are required in gas boilers. When disconnected, the valve closes and when the supply is resumed, the gas will not enter the premises.

Pipelines are made of steel, copper, metal-plastic or polypropylene products. The latter option is preferable in terms of money costs, it saves installation time. For welding, inexpensive soldering irons are used, costing from 800 rubles. Fittings, adapters from plastic to metal threads are affordable.

The expansion tank is an indispensable element of the heating system. When heated, the water expands and the surplus goes into the reserve tank.

If the inside of the device is in communication with air, the circuit is called open. If the expansion tank rubber diaphragm is not connected to air, the circuits will be closed.

There are no high demands on the strength of heat exchangers in a private house. The maximum pressure in the pipes does not exceed 2 - 3 atm. Even purely aluminum radiators can withstand such pressure, which can collapse in centralized heating systems, where the pressure reaches 14 - 15 atm.

The choice of coolant

Antifreeze in the heating system protects the inner surface of the radiators

Water or special antifreeze is chosen as the coolant. The first option is less expensive. Filling of pipes and radiators takes place through the tap from the water supply. Water as a heat carrier is justified in settlements with a constant supply of energy carrier (gas, electricity). If interruptions are frequent and prolonged, they refuse water. In the event of a shutdown for a long time in cold weather, it will freeze. Ice will destroy pipelines, radiators.

Do not pour water into the heating system of summer cottages that are rarely visited. In addition to stopping the supply of energy carriers, the boiler may stop heating water for other reasons. If the heating is not restarted in time, accidents are inevitable.

Many of us imagine the heating circuit of a one-story building quite clearly.

In the presence of a second floor, the task of organizing the heating system becomes somewhat more complicated.

Let's try to figure out what the heating scheme for a 2-storey private or public building should be. How to implement it yourself?

Let's take a look at all the components of the system first.

Boiler

The purpose of this unit is to generate heat energy, which will be transferred to the working environment of the heating circuit.

By the type of fuel used, boilers are divided into the following types:

gas;
electrical;
solid fuel;
liquid fuel;
combined (for example, capable of operating on electricity and diesel fuel).

The most convenient to operate, and therefore the most demanded, is a gas boiler. When choosing this unit, the determining parameters are the power and material of the heat exchanger.

Power

There is an opinion that the power of the heating boiler should be chosen at the rate of 100 W per square meter of heated area. However, these data are too average. Experience shows that for small buildings with an area of about 100 sq. m, the required power is approximately 130 W / kV. m, while for larger houses, the area of which reaches 500 sq. m, this figure is reduced to 80 W / kV. m. Why is it so?

Floor heating boiler in the house

The fact is that with an increase in the heated area, say, 4 times, the area of the enclosing structures, through which the heat "evaporates", increases only 2.5 times. Thus, the amount of heat loss per 1 sq. m of the heated area, decreases, respectively, the need for heat energy for the same kW becomes smaller. m.

Heat exchanger material

There are two options:

steel;
cast iron.

Cast iron is stronger than steel, and it resists corrosion better.

Pipes and radiators

In individual heating systems, steel pipes are increasingly being replaced by metal-plastic or polypropylene pipes.

These materials lose their strength at high temperatures, but in a private house, where the homeowner himself is engaged in adjusting the operation of the heating circuit, jumps in the temperature of the coolant to critical values are excluded.

Cast iron is considered a traditional material for radiators, but copper or aluminum devices are used if increased heat transfer is required. If there is high pressure in the system, bimetallic radiators should be installed instead. In them, the most critical elements are made of durable steel, and the heat-dissipating surfaces are made of soft copper or aluminum.

Armature

In heating systems, fittings of three types are used:

Shut-off: at the moment, ball valves are most often used, the disadvantages of which have been minimized with the development of technology. If the shut-off element is expected to be used frequently, it is better to install a traditional valve.
Regulating: allows you to smoothly change the volume of the passed heat carrier. Theoretically, for this purpose, shut-off valves can also be used, but they will very quickly become unusable, since they are not designed for such a tough operating mode. Today, instead of manual control valves, automatic ones, connected to temperature sensors, are actively used. Such regulators independently control the flow of the coolant, maintaining a given temperature regime.
Mayevsky valve: this element is used to remove air locks.
Expansion tank: this container receives the surplus of the working medium, which is formed due to its thermal expansion.
Circulation pump (not always used).

In some models of the Mayevsky crane, the stem can be completely unscrewed. If you do this inadvertently while the system is in working order, the coolant will rush into the room and fill everything around until you turn off the nearest shut-off valve. In order to avoid emergency situations, it is better not to install such Mayevsky cranes.

Methods for supplying coolant to the heating system

Choosing the most suitable option for the heating system, the homeowner will have to make a decision on the main question: how to get the coolant to move along the heating circuit. This task is solved in one of two ways:

naturally;
forcibly.

Heating scheme of a private house with natural circulation

As you know, a heated gas or liquid is pushed upward by a colder medium due to its lower density. This phenomenon is called convection. With the correct design of the heating system, it can play the role of an engine that will make the coolant circulate in a closed loop from pipes and radiators.

The most important element of such a scheme is the booster manifold - a vertical section of the pipeline running immediately after the boiler. The powerful upward current formed here pushes the coolant well through the circuit. In such a system, an open-type expansion tank is used, which is an ordinary tank connected to the upper point of the heating circuit.

Heating a two-storey house with natural circulation

The presence of the second floor allows the booster manifold to be made long enough, which, with good insulation of this section, provides a completely decent circulation of the coolant. However, despite this, even in two-story houses, the scheme with the natural movement of the working environment is less and less common. The reason lies in its characteristic shortcomings:

large diameter pipes are required;
on horizontal sections of the pipeline, a significant slope has to be observed - 5 - 7 cm per 1 m of length;
after bypassing the circuit, the temperature of the coolant drops by more than 25 degrees (a prerequisite for good natural circulation), therefore the boiler has to be operated in high performance mode, which reduces its service life;
the maximum pipeline length is limited to 30 meters.

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Forced way

In two-story houses, the forced circulation scheme is used much more often, if only because the length of the heating circuit in such buildings is, as a rule, more than 30 meters. Here the working medium is pumped by a special pump, which is called circulation pump. It is installed at the entrance to the boiler, where the coolant is the coldest. Since the heating system is closed, the pressure developed by such a pump does not depend on the number of storeys of the building and is determined only by the resistance of the circuit (hydraulic).

Forced circulation heating circuit

With this scheme, the speed of movement of the coolant increases, so it does not have time to cool down much. This leads to a more even distribution of heat throughout the entire circuit, as well as the possibility of operating the boiler in a gentle mode. In addition, a forced circulation system is more practical: in spring and autumn, when it is not very cold outside, it can be operated in a low-temperature mode, which would not have been possible with natural circulation of the environment. Horizontal sections of the pipeline are installed with a slope of 0.5 - 1 cm per 1 m.

Due to the high pressure developed by the pump, it is necessary to complicate the design of the expansion tank. Here it is closed and consists of two cavities separated by a flexible membrane. An expanding heat carrier enters one cavity, the other contains compressed air, the pressure of which equalizes the pressure in the system. A closed tank does not have to be located at the highest point of the circuit, it is usually mounted next to the boiler.

Prudent designers keep the boost manifold even in forced circulation systems. In this case, if the power supply is cut off and the pump is then stopped, the system will continue to operate in convection mode.

Types of heating schemes

Heating a two-story house can be organized according to one of the following schemes.

Single-pipe, two-pipe and beam heating schemes for a private house

In a small private house, you can use a sequential scheme for connecting heating radiators. In this case, the circuit will be formed by one pipe, therefore such a system is called one-pipe. This is the most inexpensive, but also the least practical option: the coolant enters the radiators farthest from the boiler relatively cold, which is why the number of sections in these devices has to be increased.

Two-pipe heating circuit with upper and lower wiring

Heat energy is distributed more evenly in the two-pipe system. It consists of two pipelines - supply and return, between which radiators are connected in parallel. For a two-story private house with a large number of rooms, such a heating system scheme is optimal.

The most expensive, but also the most convenient from the point of view of control, is the beam scheme. According to it, each radiator has its own supply and discharge pipelines, which converge in one collector. If, due to an incorrect hydraulic calculation, in some sections of a conventional two-pipe system, weak or no coolant circulation can be observed, then with a ray scheme such phenomena are completely excluded.

Horizontal and vertical schemes with bottom and top feed

In two-story private houses with a small area, a do-it-yourself heating system is often built according to a horizontal scheme.

According to it, all radiators within one floor are combined into a horizontal circuit, and to power each of these circuits, one well-insulated riser is laid through all floors.

With a large floor area, the horizontal contours would turn out to be too long, therefore, it would be impossible to maintain the required slope during their installation.

In this case, they resort to organizing heating according to a vertical scheme. In accordance with this principle, not those radiators that are located on the same floor are combined, but mounted above each other on different floors. For this, several risers are laid.

They can be connected in series:

the coolant from the boiler rises along one riser;
then, along the lintel located on the second floor or in the attic, it enters the second riser, along which it moves in the opposite direction.

But they also practice parallel connection of risers. For this, two circular pipelines are laid, one of which plays the role of a distribution manifold (all risers are supplied from it), and the second performs the function of a "return" (cooled coolant enters here).

If the house has an insulated attic or technical floor, the first of the pipelines can be placed here. In this case, the system is said to be top wired. In the absence of such a room, both pipelines have to be located in the basement or basement (lower wiring).

When designing heating in a private house, many owners are wondering which system to choose: one-pipe or two-pipe? The first is simpler, the second more practical. : its strengths and weaknesses, as well as classification and hydraulic calculation.

You will find out detailed information about a one-pipe heating system in the material.

Video on the topic

Now in the projects of private residential buildings, a heating scheme for a two-story house with forced circulation is being laid, as more optimal and modern. Some homeowners still prefer natural circulation heating, seeing its benefits. To find out the advantages of each of their heating schemes, consider the various options for pipe routing in a two-story house.

Natural circulation of heated water through pipes is still relevant, but a thing of the past

Now, in heating projects for a private two-story house, you will no longer find drawings of heating circuits that work without the inclusion of circulation pumps in the circuit. But not so long ago, heating of private households with individual water heating was carried out exclusively thanks to the natural movement of water through pipes. In some houses, built and equipped with everything necessary earlier, heating systems with gravity circulation of the coolant function to this day.

How does the liquid move in such pipe circuits? The circulation here is provided by the difference in the density of water with different temperatures. Hot liquid is lighter (less density), therefore it tends upward, colder one - downward. The coolant heated by the boiler goes up the riser, it is replaced by cooled water from the return pipeline. This is called convection and provides half of the energy required for natural circulation.

The other half of the driving force comes from gravity. In order for the force of gravity to act more efficiently, the horizontal pipes of the circuit (loungers) are installed with a slope in the direction of the movement of the coolant. The supply pipe is inclined towards the heating radiators, the return lounger towards the boiler. In addition to the slope of pipes in a gravity loop, the following factors are of great importance for the successful implementation of circulation:

the position of the boiler relative to the return pipe (the lower the unit is installed, the better);
diameter of pipe communications (the wider the clearance of the pipeline, the lower the resistance);
section of internal holes in batteries (the same pattern as for pipes).

Compliance with these rules allows you to make an effective gravity circuit in the house with your own hands. However, the conditions that must be observed when installing a system with a natural movement of the coolant are the reason for such disadvantages:

bulky pipes (usually steel) cannot be laid hidden, they are always in sight;
it is necessary to make a deepened platform for the boiler, which makes its maintenance inconvenient;
it is necessary to maintain the difference between hot and cooled coolant at least 25 degrees;
the optimal ones, having the largest internal clearance and less susceptibility to corrosion (with natural circulation in the coolant, there is a lot of air), are cast iron (the choice is small);
large volume of coolant and the need to mount bulky;
it is difficult to carry out correct heat engineering calculations for uniform heating of rooms.

In addition, the gravity circuit is not able to fully heat the overall buildings. Effective natural circulation is possible with the length of the loungers up to 45 m and the area up to 180 m 2 (in a two-storey house). These disadvantages make gravity circuits the least desirable for homeowners. But still, adherents of gravity heating systems remain, arguing their preferences with such advantages of gravity circuits:

independence from an uninterrupted supply of electricity;
noiseless movement of liquid through pipes;
the efficiency of the heating system during the operation of solid fuel boilers (high inertia partially neutralizes frequent and significant temperature drops).

When installing gravitational circuits, two pipe routing schemes are used - one-pipe, when the coolant from the batteries is discharged through the same pipe that is supplied, and two-pipe, when the liquid is supplied and removed back to the boiler by two communications. For natural circulation, the same wiring diagrams apply. The coolant is supplied to the second floor through a riser extending from the boiler, the cooled liquid is discharged from above through a return vertical pipe. Loungers on both floors are connected to the risers according to the applied wiring diagram of heating communications.

Forced fluid flow system - optimal by today's standards

When developing a modern project for heating a two-story house, the authors of the document will certainly include a heating circuit with a circulation pump in it. Systems with the natural movement of liquid through pipes do not fit into the concept of a modern interior, moreover, forced circulation provides the best performance characteristics of hot water heating, especially in private houses with a large area.

Forced circulation makes it much easier to relate to the arrangement of the heating system elements relative to each other, but still there are general rules for the boiler piping, the preferred connection of the heating batteries, and the laying of pipe communications. Despite the presence of a circulation pump in the circuit, when installing the wiring, they try to minimize the resistance of pipes, their connections and transitions in order to reduce the load on the pumping device and avoid fluid turbulence in difficult-to-reach places.

The use of forced circulation in the pipe loop allows you to achieve the following operational advantages:

high speed of fluid movement ensures uniform heating of all heat exchangers (batteries), due to which better heating of various rooms is achieved;
forced injection of the coolant removes the restriction from the total heating area, allowing communications of any length;
a circuit with a circulation pump works effectively at low liquid temperatures (less than 60 degrees), making it easier to maintain the optimum temperature in the rooms of a private house;
low temperature of the liquid and low pressure (within 3 bar) allows the use of inexpensive plastic pipes for the installation of the heating system;
the diameter of thermal communications is much smaller than in a system with natural circulation and their hidden laying is possible without observing natural slopes;
the ability to operate heating radiators of any type (preference is given to aluminum batteries);
low inertia of heating (it takes no more than half an hour from starting the boiler to the maximum temperature set by the radiators);
the ability to make the circuit closed using a membrane expansion tank (although the installation of an open system is also not excluded);
thermoregulation can be carried out both as a whole in the system, and zonal or pointwise (regulate the temperature on each heater separately).

Another advantage of the forced heating system of a two-story private house is the arbitrary choice of the place for installing the boiler. Usually, it is mounted on the ground floor or in the basement, if there is a basement room, but the heat generator does not need to be specially deepened and the level of its location relative to the return pipe must be calculated. Both floor-standing and wall-mounted installation of the boiler is allowed, which provides a wide range of suitable equipment models according to the personal preferences of the homeowner.

Despite the technical perfection of heating with forced fluid movement, such a system has disadvantages. Firstly, this is the noise that is generated during the rapid circulation of the coolant through the pipes, which is especially amplified in places of narrowing, sharp turns of the pipeline. Often, the noise of a moving fluid is a sign of excessive power (performance) of the circulation pump applicable to a given heating circuit.

Secondly, the operation of water heating depends on electricity, which is necessary for the constant circulation of the coolant by a circulation pump. The circuit diagram usually does not facilitate the natural movement of fluid, therefore, during prolonged power outages (if there is no device for uninterrupted power supply), the house remains unheated.

Like a circuit with natural circulation, heating a two-story house with forced circulation of a coolant is done with one-pipe and two-pipe wiring. How such schemes look correctly will be described further.

One-pipe circuit with a circulation pump - easy to make, but far from perfect

With a one-pipe wiring diagram with the inclusion of a circulation pump in the circuit (all heaters on the floor are connected to the same communication), a hot coolant is supplied through it and the cooled liquid is discharged into it. Due to the high circulation rate with a small length of the lounger, the temperature difference between the radiator first from the riser and the extreme battery is insignificant. But with a large contour length, the difference becomes noticeable.

Often, such a wiring diagram is the result of an improvement in a single-pipe heating circuit with natural circulation, when a circulation pump is cut into the system, while heating has been carried out for a long time.

One-pipe distribution can function both as an open system and using a diaphragm expansion tank. If it is an advanced system, an atmospheric expansion tank is usually left. When the circuit is made from scratch, a closed membrane-type tank is installed.

The advantage of such a circuit is the possibility of its temporary operation without the participation of a circulation pump (in the event of a power outage), although with less efficiency. In order for the heating to operate in two modes, the pump is installed in a bypass - a special pipe bypass loop with a system of valves and shut-off valves. The circulating pump is installed on a thinner pipe that bends around the main line. When the coolant pumping device is working, the liquid moves in a bypass way, while the valve on the central pipe is closed. If there is no electricity, the bypass valve is closed, but it is opened on the main line and the coolant begins to circulate naturally.

A 2-storey private house is effective only with a small floor area. In such situations, it makes sense to do the wiring with one pipeline - it turns out more economical in terms of the cost of materials (pipes, fittings) and much faster. If the square of the floors is significant, you will have to spend money on pipes and make the most efficient wiring using two thermal communications.

Two-pipe heating distribution - options for a two-story house, schemes

All the advantages of a circuit with forced movement of the coolant are realized during the construction and operation of a two-story house. With such a wiring, which has several options for working schemes, the supply of the coolant and its removal from the batteries is carried out through different communications. Radiators are connected to the system in parallel, that is, independently of each other.

The hot coolant from the boiler enters the riser, from which a supply branch leaves on each floor and supplies each heater. From the batteries, the outlet pipes discharge the cooled liquid into the return communication. "Cold" sunbeds flow into a discharge riser, which turns into a return pipe on the ground floor. On the return line, before entering the boiler, the following are sequentially installed:

membrane expansion tank;
circulation pump in the bypass system with a complex of shut-off valves;
safety valve that relieves excess pressure in the heating pipe circuit.

Independent supply of the coolant to each battery in a two-pipe heating circuit makes it possible to regulate (including automatically) the rate of fluid flow through the radiator and thereby change the temperature of the heater. This is done manually by means of a shut-off valve at the inlet of the heating medium or by means of a thermostatic valve, which automatically adjusts the opening of the inlet in accordance with the set room temperature. Balancing valves are often installed at the outlet of the radiators, with the help of which the pressure is equalized in each section of the system and in the entire circuit.

A two-pipe heating system can be implemented in several versions, and a different scheme can be applied on different floors. The simplest wiring with two pipes is called dead-end. It consists in the fact that both pipes (inlet and outlet) are laid in parallel, alternately connecting along the way to the batteries, and eventually close on the last heater. The cross-section of the pipes (both) decreases as they approach the last radiator. Such a wiring requires careful pressure regulation using balancing taps (valves) in order to achieve a uniform flow of coolant to the batteries.

The next one and the pipe connections are called "Tichelmann's loop" or counter. Its essence is that the supply pipe and return pipe, which have the same diameter throughout, are fed to the radiators and connected from opposite sides. This wiring is more optimal and does not require system balancing.

The most perfect, but also the most material-intensive, is the collector heating system of a two-story house. Each heating device on the floor is supplied individually, separate supply and return pipes are supplied from the collector to the radiators. In addition to batteries, floor convectors, underfloor heating, fan coil units can be connected to the collector. The advantage is that a heating medium with the required pressure, temperature and circulation rate is supplied to each heating device or system. All these parameters are controlled by devices (servo drives, fluid mixers, thermostats, valve systems) installed on the distribution manifolds.

The topic of this article is a diagram of a two-pipe heating system of a two-story house and its practical implementation. The reader and I have to figure out how to install heating and connect heating devices, how to achieve uniform heating of all batteries, which pipes and radiators to buy for installing the heating system. Let's get started.

Why two-pipe

Why should the heating scheme be exactly two-pipe?

Because, in comparison with the simpler one-pipe Leningrad, it allows you to achieve a more uniform heating of the batteries. With a long single-pipe circuit length, the temperature difference between the supply and return will inevitably become noticeable and force the increase in the size of the radiators, which is unprofitable and not always applicable from the point of view of room design.

A multi-cell battery is a dubious decoration for a living room.

Note that the one-pipe system is cheaper to install (simply because of the shorter total filling length) and more fault-tolerant. As long as there is a differential pressure at the ends of the filling, it is impossible in principle to stop circulation in it.

One-pipe Leningradka is the leader in fault tolerance.

Device

All schemes of a two-pipe heating system of a two-story house have one thing in common: they have separate supply and return outlets. The fillings are interconnected by jumpers with heating devices installed in their gap.

Top and bottom filling

Depending on the location of the filing filling, schemes with lower and upper filling are distinguished.

In the first case, both the supply and return lines of the circuit are located in the basement and are connected by paired risers. Those, in turn, are interconnected by jumpers located in the rooms of the upper floor or in the attic;

Removing lintels in a cold attic is not a good idea. When the circuit stops in cold weather, the water hangs in the risers, and the pipes in the attic are stuck in ice within an hour after the heating is turned off.

In the second case, the supply is divorced in the attic, and the return flow is in the basement. Such a scheme greatly simplifies the reset and start-up of the system: when resetting, it is enough to open the vent on the expansion tank located at the upper filling point of the supply, and all the water hanging in the pipes will drain down; at start-up, air is vented not at every jumper between, but only at the notorious waste vent in the expansion tank.

In my opinion, it is top filling is the most convenient in terms of operation... In houses with an overhead outlet, in my memory, there have never been any serious accidents associated with defrosting heating, while in houses with a bottom filling, radiators and connections in the porches had to be warmed up every winter.

Gravitational and forced

A two-pipe heating system in a two-story private house can be implemented with forced circulation of the coolant (a circulation pump is used for this) or with natural circulation, due to the difference in the density of the hot and cold coolant.

Forced circulation schemes are advantageous in that:

Provide a high speed of movement of the coolant and, accordingly, a more uniform and faster heating of radiators;
Allow to get by with a smaller diameter of the filling.

Their main drawback is volatility: The pump needs 24/7 power. If the problem of short-term blackouts can be solved by installing an uninterruptible power supply, then a power outage of several days will leave your home without heat.

Natural circulation systems are completely non-volatile.

How does such a heating system work?

The boiler (usually solid fuel) is lowered as low as possible - into the basement or pit. The radiators are mounted above the boiler heat exchanger. The difference in height between them, in fact, will provide circulation;

Immediately after the boiler, a booster pipe is mounted - a vertical filling section that rises to the ceiling of the second floor or to the attic. Through it, the water heated in the boiler rises to the upper point of the contour, from where it moves along the filling by gravity, due to its own gravity. Hence, by the way, the name of such a system - "gravitational".
Immediately after the booster pipe, an open expansion tank is mounted, which at the same time performs the function of a safety valve and a filling funnel for filling the circuit with water. If the coolant boils, steam will leave the filling through the tank lid. Through it, you can always add water instead of discarded or evaporated;

Both filling - supply and return - are mounted with a slight constant slope along the direction of movement of the coolant;
The inner diameter of the filling is made as large as possible (not less than DU32, more often DU40 - DU50). The large diameter compensates for the minimum hydraulic head created by the temperature difference.

The hydraulic resistance decreases with an increase in the internal section of the pipe. The thicker the spouts and liners, the faster the water circulates in them.

How it works?

Due to the reduced density, the hot water heated by the boiler is displaced to the upper point of the circuit by colder and denser masses of the heat carrier;
From there, it continues to move along the filling laid with a slope, gradually giving off heat to the air in the rooms through the heating devices;
The coolant that has given off the heat returns to the boiler and is involved in a repeated circulation cycle.

The obvious disadvantages of the gravitational heating system are high inertia, significant temperature differences between the first and the last batteries along the movement of water, and high costs for installing the filling.

For those where interruptions in power supply are of a periodic nature, the installation of combined heating systems is practiced. Actually, they represent a classic gravity scheme with a circulation pump embedded in parallel filling. A ball check valve is installed between the pump inlets.

This scheme works like this:

When the pump is on, water flows through its inset. Due to the excess pressure at the outlet of the pump, the check valve is closed;
When the pump is turned off, the valve opens and the water continues to circulate slowly with natural urge.

Let me emphasize: only ball valves are used in such circuits. A spring loaded check valve requires a significant differential pressure to open. Even if it does open (which is unlikely), a significant part of the hydraulic head will be lost on it.

Convection and trench

The classic heating scheme with wall or floor radiators is called convection: heat is distributed by the heated air currents rising from the heating devices. Unfortunately, the mixing of air with these currents is not effective enough: the temperature under the ceiling is always several degrees higher than at floor level.

Since the inhabitants of the house, as a rule, do not have the habit of spending their leisure time on the ceiling, a stronger heating of the upper part of the room volume has only one consequence - an increase in heat loss through the ceiling and roof.

Warm floorhas no such disadvantage... Pipes laid in the screed or under the final floor covering warm up the room as much as possible exactly at the floor level, which makes it possible to achieve a comfortable temperature distribution at the lowest cost.

Can the floor be combined with a two-pipe system? If all the heating of the house is done by low-temperature underfloor heating, then only the section between the boiler and the collectors will be two-pipe. Further wiring will be collector (beam).

You see, underfloor heating has a limitation on the maximum length of the circuit (100-120 meters), so the heating of a house usually consists of several parallel-connected circuits.

If the underfloor heating is connected in parallel with high-temperature heating with radiators, it needs a temperature matching unit with a temperature sensor, a three-way or two-way valve and its own circulation pump.

The pump drives the coolant inside the low-temperature part of the circuit; the valve opens and lets a new portion of hot water into the pipes of the warm floor only when it cools down to a certain temperature.

Balancing

What is balancing and why is it needed?

To explain this, I need to clarify a couple more concepts.

A dead-end heating system for a private house is a circuit in which, when the coolant passes from the supply to the return thread, the direction of its movement is reversed. Dead-end schemes are used if a panoramic window, a high opening or other obstacle interferes with the wiring in a closed loop;

A passing system (it is also a Tichelman loop) means that the water moves in one direction both along the flow and along the return.

Tichelman's loop is actually several parallel loops of the same length and the same hydraulic resistance. The temperature of the batteries in such a heating system will always be approximately the same.

Tichelman's loop - several parallel contours of the same length.

With a dead-end system, everything is much more complicated. The jumpers between the supply and return outlets with radiators on them are several circuits of different lengths and, accordingly, with different hydraulic resistance.

As you might guess, the difference in hydraulic resistance will affect the rate of circulation of the coolant through the batteries near and far from the boiler. The bulk of the water will move along a short path; distant devices will be noticeably colder, and in severe frosts they can even be defrosted. There were precedents in my memory, and more than once.

To solve this problem, the throughput of the radiators closest to the boiler is artificially limited by throttling. For this purpose, chokes are used that allow you to make adjustments with your own hands, or thermal heads that regulate the patency in automatic mode and maintain the set temperature.

The temperature of the batteries after adjusting the throttles changes within half an hour - an hour. Manual balancing of a sufficiently large circuit can take up to two days.

Materials (edit)

Radiators

In general, aluminum sectional batteries will be the best choice for an autonomous heating system. With a maximum (up to 200-210 watts per section) heat transfer, they are attracted by a very affordable section price (from 250 rubles).

Here is the formula for calculating the heat demand of a house: Q = V * Dt * k / 860.

In it:

Q-power in kW;
V-volume of all heated rooms in cubic meters;
Dt is the temperature difference inside and outside the house;
k - coefficient determined by the quality of the house insulation.

Two variables need comments.

Dt is calculated as the difference between the temperature corresponding to sanitary standards (20 degrees for regions with the temperature of the coldest five-day winter to -31C and 22 for colder regions) and the temperature of the coldest five-day period.

Winter temperatures for some cities in Russia. The value we need is in the first column.

The value for k can be taken from the following table:

For example, for a two-story house 6x12 meters in size and 7 meters high, located in Sevastopol (the temperature of the coldest five-day period is -11), without external insulation and with single-chamber double-glazed windows, the heat demand will be: 6 * 12 * 7 * (+ 20 - -11 ) * 1.5 / 860 = 18 kW.

With a thermal power of 18 KW and a section capacity of 200 watts declared by the manufacturer, their total number will be 18000/200 = 90 (for example, 9 radiators with 10 sections each).

Please note that the manufacturer's data is correct only for the delta of temperatures between the coolant and the room at 70C (say, 90/20). Heat transfer decreases in proportion to the temperature difference and at 60/25 it will be only 100 watts per section.

Pipes

For the distribution of heating in a private house, you can safely use all types of high-temperature (with a declared operating temperature of 90C) plastic and metal-plastic pipes. I have aluminum-reinforced polypropylene installed in my house; with the same success it was possible to choose metal-plastic on press-fittings.

The fact is that the heating parameters in the autonomous circuit with the minimum sanity of its owner are controlled and absolutely stable:

The coolant temperature is usually kept in the range of 50-75 degrees;
The pressure in a closed system does not exceed 2.5 kgf / cm2.

The stability of the pressure in a closed circuit during temperature fluctuations is ensured by a correctly sized expansion tank. Usually it is taken equal to about 10% of the volume of the coolant in the circuit. Its quantity is easiest to measure by filling the heating system with water and draining it into any measuring container.

And since all the parameters are predictable and stable, is it worth overpaying for reliability that simply won't be in demand?

For heating, do not use only metal-plastic on compression fittings with union nuts. The instruction is due to the fact that it is very sensitive to the slightest assembly errors (in particular, to the displacement of the rubber O-rings on the fitting) and often begins to leak at the joints after several heating and cooling cycles.

Using metal-polymer pipes with compression fittings for heating is not a good idea.

What should be diameter of battery connections and spills?

The filling diameter depends on the way the circulation is induced. For the gravitational system I have already given the parameters; for a circuit with forced circulation, the filling diameter is determined by the heat load on it. Here are the data for an average speed of movement of the coolant of 0.7 m / s (at this speed there is still no hydraulic noise):

In practice, with a house area of up to 200 meters, a polypropylene pipe with a diameter of 25 mm is bought for bottling, for connecting radiators - a diameter of 20 mm.

Do not forget that only metal pipes are marked with a nominal bore approximately equal to the inner diameter. For plastic, the outer diameter and wall thickness are indicated. You can calculate the inner section of the pipe by subtracting twice the wall thickness from the outer diameter.

Boiler piping

In a closed system with forced circulation, it includes:

Expansion tank;
Circulation pump;
Safety group - pressure gauge, safety valve and automatic air vent.

In addition, all radiators located above the filling are equipped with Mayevsky taps or automatic air vents. On brackets above filling are placed the same air vents, and on the brackets located below bottling - dumpers for complete drainage of pipes.

Some types of boilers boast a safety group installed inside the body, a pump and an expansion tank. Before going shopping, do not be too lazy to study the description of the device.

Connecting radiators

For sectional radiators, three connection methods are possible:

One-sided side;
Bilateral bottom;
Diagonal.

Which one should you choose?

The answer depends on two factors:

Number of battery sections;
Its location in relation to the filling and / or riser.

With a short heater length (up to 7-10 sections) and standing wiring, lateral connection will be optimal. The difference in diameter between the radiator manifolds and the vertical channels inside the section will ensure its uniform heating along its entire length.

If the number of sections is more than 10 and the heating device is connected to a riser pipe or a filling located above it, our choice is a diagonal connection. It will warm up all sections, regardless of their number.

With a long battery length and location over bottling a two-way bottom connection would be more practical.

Here are the benefits:

The radiator will begin to warm up immediately after starting the circuit, even without bleeding air. The air lock will be forced out by excess pressure into the upper manifold and will not interfere with the circulation through the lower one. In this case, the sections will be heated along the entire height due to their own thermal conductivity;
In an open heating circuit, a periodic renewal of the coolant will contribute to the gradual silting of the batteries and a drop in their heat transfer. However, the continuous circulation of water through the lower collector will prevent sludge from collecting in it: the battery will not need to be flushed in principle. To flush the filling, it is enough to bypass the circuit for discharge once every two to three years.

Conclusion

So, we got acquainted with the varieties of two-pipe systems and with the features of their installation in a private house. The dear reader can learn more information by watching the video in this article. I look forward to your additions and comments. Good luck, comrades!

Two-story houses have gained great popularity in the vastness of our country. They are appreciated not only for their comfort, but also for the rational use of the land area, the economy of building materials and the relative ease of construction. At the same time, competently organizing the heating of two-story housing is not an easy task. There are subtleties and secrets here, without knowing which the house will be heated unevenly or ineffectively. Let's discuss the main heating systems that can be considered for a two-story home.

A feature of the heating system with natural circulation of a two-story house is the absence of a pump that creates pressure in the pipes. The movement of water is provided by the laws of hydraulics and thermodynamics, for which the pipes are installed at a certain angle to each other at a given height. Although this system has a slightly lower thermal efficiency, it is completely autonomous, that is, it does not depend on the power supply and does not consume additional energy.

Heating with natural circulation of a two-story house can be carried out both according to one-pipe and two-pipe schemes. The advantages and disadvantages of these types are discussed in detail below. Here are a few things to keep in mind when organizing any type of natural circulation:

large diameter pipes will be required, otherwise the movement of water will be difficult;
it is unacceptable to use closed-type expansion tanks - this entails the creation of excessive pressure and the system will no longer work by gravity;
the highest point of the pipeline is chosen as the location of the expansion tank, while the boiler is located at the bottom, most often slightly below the return line.

When installing a system with natural circulation in a two-story house, a significant waste of materials and a decrease in heat transfer are inevitable. Such difficulties are justified only in one case - when the risk of a power outage in the cold season is too great.

One-pipe heating systems

A two-story house is understood as a complex of radiators that use the same line to receive hot coolant and discharge the cooled one. This allows you to significantly save on materials, but entails a number of disadvantages:

increased boiler power is required;
the temperature of the water in the mains gradually decreases from the radiator to the radiator;
each next radiator must have more sections than the previous one (which is a consequence of the previous point).

Thus, the implementation of one-pipe schemes makes sense only in regions with a relatively mild climate for heating small houses.

Heating "Leningradka"

As you might guess, this heating scheme was developed in the Soviet Union and was widely implemented in small buildings in the northern capital. The basis of "Leningradka" is one common highway, which runs along the perimeter of the premises below the level of the installation of radiators. The pipes cut into it from above, and to redirect the flow of the coolant under each radiator, the pipe is narrowed or a control valve is installed.

Both natural and forced circulation are possible. In the first case, it is recommended to install no more than four radiators, in the second - no more than six. The connection of seven to eight radiators is possible only after precise engineering calculations; with a larger number of heat consumers, the system is considered ineffective.

Alternative types of one-pipe heating

A further evolution of the "Leningrad" can be considered systems with line breaks and sub-radiator constrictions, which play the role of "bottlenecks", redirecting the fluid flow. This allows you to simplify the main line, getting rid of restrictions and valves, as well as to place radiators away from the area of laying the main pipes. With sufficient power of the injection pump in forced circulation cycles, a slight increase in heated areas is possible.

Two-pipe heating

Found application in large two-story houses, as it has significantly less heat loss from radiator to radiator. The structure of the system includes two main lines: hot and cold. In the first, the heated liquid is supplied to the heat consumers, in the second, the cooled heat carrier is discharged. In this case, the highways have no direct connection with each other.

On a separate primary hot line branch, significantly higher than the pipelines. Closed models are usually chosen. Valves can be cut in front of the radiators, allowing you to selectively disconnect individual rooms from heating, however, overlapping of too many valves can lead to overpressure and leaks, especially in systems with forced circulation and with incorrect thermal calculations.

Dead-end scheme and "Tichelman's loop"

Initially, all two-pipe heating systems worked in a direct dead-end scheme. This meant that the radiator, which was the first to receive the hot coolant, was the first to give back the cooled one, which entails a consequent loss of pressure in the radiators and a decrease in their efficiency. Even if not as significant as with a one-pipe layout. The dead-end scheme is still used for heating small buildings, since it requires significantly less material consumption during installation and is not so demanding on pump power.

The solution to the pressure drop problem was proposed by engineer Albert Tichelman. He developed a reversible coolant return system or, more simply, a return loop. Thus, the radiator, which first received the coolant, dumped it last, and the last installed radiator drained the cooled liquid earlier than the rest. This, of course, doubled the length of the return line. The dead-end scheme is well suited for heating a two-story house.

Beam scheme

Another branch of the evolution of a dead-end heating system was the so-called radial scheme. It assumes the presence of an additional unit - a distribution manifold. It is necessary to separate the primary and return lines to each radiator separately, which ensures the circulation of liquid with equal temperature and equal pressure in all elements of the system.

Further complication of the heating system in comparison with dead-end and lavalier schemes led to an even greater consumption of pipes when laying highways. However, it pays off in high efficiency. The requirements for the expansion tank and the injection pump are the same as in the "Tichelman loop".

Underfloor heating

The main "feature" of the warm floor is the installation of one large, but low-power "radiator" in the underground space, instead of using a system of standard mounted radiators. This ensures a more even distribution of heat, increases the comfort in the room and, if the system is correctly implemented, reduces energy consumption. However, the warm floor is not without its drawbacks. These include:

a long warm-up time for a completely cooled room;
the possibility of condensation due to almost complete isolation from external factors;
the complexity of the calculation and installation of the system.

In the course of recent studies, it was noted that a room with a warm floor, all other factors being equal, can be heated to a temperature 2ºC lower than a room with a classic heating, and this will not affect human comfort in any way. This fact alone can save up to 10-15% of energy.

Today, underfloor heating is quite often used in heating a two-story house. The system can act as the main one, but for this it is important to do all the heat engineering calculations.

Heating by gas boiler

Gas boilers are the main source of energy in most modern heating systems. They guarantee high performance at relatively low energy costs, are distinguished by high reliability and safety, of course, subject to all installation rules and regulations.

Nevertheless, in recent years, there has been a tendency for a constant increase in prices for natural gas, which will soon equate the unit costs of its purchase with the costs of maintaining an electric heating system. And two-story houses are most often built with large areas. As long as gas availability remains, we recommend heating your two-story house with a gas boiler.

Which heating scheme to choose?

When choosing a specific type of heating system, you should be guided, first of all, by the characteristics of the building, pay attention to the availability of electricity and financial possibilities .. If you have engineering documents, look into them, as a rule, all the necessary numbers are indicated. Otherwise, you will have to carry out all measurements yourself. The required minimum is the floor area, the volume of the room, the thickness and material of the load-bearing walls and partitions.

After that, it is worth analyzing the climatic features of the region, the cost and availability of various types of energy. On the basis of these data, the initial choice of options for organizing heating is carried out, after which the planned costs for their purchase and installation, as well as future maintenance, are calculated. It is economic indicators, both short-term and strategic, that are decisive when choosing a specific type of heating.

If there are difficulties with finances, the availability of light is unstable, and coal is the only source of energy, then it may be worth looking towards simple one-pipe heating systems. If there is gas, a stable supply of light and finances allow, then you can look towards the two-pipe and radial heating systems of a two-story house.