Two -pipe heating system of a multi -storey building scheme

Knowing how our heating systems operate is crucial for keeping our homes warm and comfortable during the colder months. Two-pipe heating systems are a typical kind of heating system found in multi-story buildings. The efficient distribution of heat throughout the building by this system guarantees the comfort of every occupant.

Two-pipe systems have separate pipes for supplying hot water to the radiators and returning cooled water back to the boiler. This is in contrast to single-pipe systems, where hot water heats the radiators through one pipe and returns through the same pipe after cooling down. Because of this design, each radiator’s temperature can be adjusted more precisely, ensuring that the building is heated more evenly throughout.

A central boiler heats water and pumps it through the supply pipes to the radiators in each apartment or unit, according to the schematic of a two-pipe heating system in a multi-story building. Warming the rooms, hot water moves through radiators and releases heat into the surrounding area. After cooling down, the water circulates and is reheated inside the boiler via the return pipes.

A two-pipe heating system’s capacity to deliver consistent heating on various building floors is one of its benefits. Temperature differences between floors are less likely because each radiator has its own supply and return pipes. This promotes comfort and satisfaction by guaranteeing that residents on higher floors receive the same amount of warmth as those on lower floors.

Furthermore, two-pipe systems provide more control and zoning flexibility. Building managers have the ability to modify the hot water flow to specific radiators or groups of radiators, enabling personalized heating configurations according to the unique requirements of every space or unit. This degree of control not only optimizes comfort but also aids in energy optimization, which may ultimately result in cost savings.

How to correctly install a two -pipe heating system

The heating system uses water most frequently. Over 67% of all structures in our nation are heated thanks to it. She comes in a few varieties, the most well-liked being the two-pipe. In order to give you as much information as possible about two-pipe heating systems, we have set ourselves the task of explaining what they are in greater detail, both mechanical and natural circulation.

Two pipe heating systems with mechanical circulation are shown in the picture.

What is based on the principle of operation

There won’t be any surprises in this instance because the system is a closed contour that allows heated coolant to move from the heater to the radiators. The other designs that use water for heating follow the same principle.

The usage of two pipeline branches concurrently is the only distinction:

• The first – transports and distributes hot coolant;
• second – removes the cooled liquid from heating radiators and returns it to the boiler.

Two-pipe horizontal heating system that shows the coolant’s movement direction

Advantage

The two-pipe design has clear advantages over the alternative, which is less popular despite being simpler to implement and less expensive. Think about them in greater detail:

• 2 Pipe heating system allows you to supply a coolant to each radiator, the temperature of which will have the same value for everyone.
• You can set the necessary level of heating for all rooms using the thermostat. It can, if necessary, be installed on each battery.
• Temperature control on a certain radiator does not affect the temperature on other heating devices.

Because there are less pressure losses, you can use a circulation pump that is less powerful and more cost-effective.

The instructions permit the system to be installed in apartment buildings as well as one- or multi-story buildings.

Controversial reinforcement on pipeline supplies enables system repairs without halting the operation of the entire system.

How to connect a one-pipe or two-pipe heating system correctly

The pipeline’s double length, which raises costs in comparison to the single-pipe option, is typically mentioned as one of its drawbacks. Since the pipes in this instance have a small diameter, the fasteners, valves, connections, and shaped products also have small dimensions, even though this cannot be viewed as a negative attribute.

As a matter of fact, the overall expenses will barely surpass those of a single-pipe heating system. Additionally, you will receive a great deal more benefits.

Heating systems consisting of one or two pipes and an open expansion tank

The two primary categories of heating systems are open and closed.

The type of expansion tank used in the design serves as the primary criterion for such a separation.

1. In the open version, it is placed on the upper section of the circuit, from where the coolant can evaporate freely. In this case, the internal pressure of the system will be relatively low.

1. A closed standard two -pipe option is equipped with an expansion tank of a membrane type, allowing fluids to circulate along the contour under compulsory pressure. Since there is no evaporation, this allows you to use in the form of a coolant in addition to water more practical solutions, the basis of which is glycols. Closed systems are considered the safest and most environmentally friendly.

Heating a private home with two pipes while keeping your hands closed

The following can be highlighted, depending on where the pipelines connecting each structural element are located:

1. Vertical two -pipe heating system, when batteries are connected to a vertical riser. Use it in multi -storey buildings, giving the opportunity to attach each floor to it separately. The main advantage of the design is the lack of air plugs when using it. The price of the arrangement will be higher than other options.

A two-pipe vertical heating system featuring multiple types of air intake

1. The horizontal 2-pipe heating system is usually used in one-story buildings with a large area. Connection of heating devices is carried out to a horizontal pipeline. The discharge of accumulated air is carried out using the crane of the Maevsky.

Advice: In this situation, it would be best to install the wiring risers in the hallway or on the landing.

Use these two primary designs:

1. Lower, when the pipeline going from the boiler is laid in the lower part of the structure, for example, in the underground space, floor or basement. The reverse is located even lower, and to obtain normal circulation of the coolant, the boiler is below, so that all heating batteries are placed above it.

Advice: Make sure the circuit has an air line installed from above. It will assist in clearing the network of extra air.

1. Upper, when the divorce line passes along the top of the structure, and the expansion tank is mounted in the highest place of the contour. Usually pass the pipeline in the insulated attic, which is unacceptable for buildings with a flat roof.

Advice: For both horizontal and vertical heating systems, there are two wiring options.

A 2-pipe heating scheme that passes

Hydraulic calculation

Because it will vary depending on the structure, it needs to be completed before beginning work on the installation of heating structures. Both the vertical and horizontal two-pipe heating systems’ hydraulic calculations are often performed using the previously completed "draft" scheme, which includes every component.

The pipeline’s most loaded ring is identified during the calculations, and it should be used as the object to be calculated and split into conditional sections.

Consequently, the home’s owner will be given:

• the magnitude of the possible loss of pressure in the circuit;
• The most optimal diameter of pipelines;
• The area of radiators necessary for heating from which you can get the number of heating devices.

Several techniques are used in the hydraulic calculation of the two-pipe horizontal heating system.

Below, we’ll discuss the most typical:

1. Calculations are carried out taking into account the characteristics of the resistance and values of the conductivity. Thanks to this, it is possible to obtain real data on the temperature of each element of the heating circuit and the accurate water consumption.

1. Calculations are carried out according to the specific loss of pressure. As a result, a visual physical picture of the process is obtained, which demonstrates the real distribution of resistance in the pipeline.

This means that you can determine the precise temperature parameters and coolant flow rate at any point in the circuit by using the hydraulic calculation of the two-pipe heating system. This will serve as the framework for the building’s heating plan organization.

How are multi-story buildings’ one- and two-pipe heating systems installed?

Following calculations, the precise circuit design, and the acquisition of the required equipment, the 2-pipe heating system installation process begins.

The steps involved in putting it into practice will be explained below:

1. Install the heating boiler. The best option is a small separate room where ventilation is correctly equipped, which will derive the combustion products. We recommend that the floor and walls are faced with specially designed refractory materials. Place the boiler in the distance from the walls, with a comfortable approach to it for maintenance.

1. Fasten the circulation pump on the pipeline and the distribution collector, if it is provided for by the plan.

1. Draw the pipeline from the boiler to radiators. Make small holes in the walls, which then fill in a cement mortar. Connections depend on the composition of the pipe material .

Heating systems with two pipes and one pipe: a schematic of radiator connections

1. Connect radiators. The heating circuit of each battery should consist of two pipes – the upper with hot, lower with chilled coolant. DIY radiators installation under the windows using special brackets.

The ideal separation from:

• radiators – 100 mm;
• floor – about 120 mm;
• walls-20-50 mm.

Install the shut-off and regulatory accessories at the output and entrance. Thermals will make it simple to set the room’s temperature to a comfortable level.

1. Conduct a system check after all the work is completed.

This article explained the differences between a vertical and horizontal two-pipe heating system, which are both commonly used today to maintain a comfortable temperature in homes and commercial buildings. Its indisputable benefits have made it extremely appealing to customers.

For heating purposes, over two thirds of homes and businesses opted for this option. It requires careful planning and a proficient hydraulic calculation.

The article’s video will assist you in finding more information about this subject.

The water heating system is two -pipe: varieties and installation

The most popular type of heating system among the various ways to wire thermal trunks throughout the house is the two-pipe system. When installing radiators and highways, it is a practical, dependable, and easy task to complete—especially when using contemporary materials. If desired, the average user can put together such a heating system by hand without hiring installers, whose work is frequently of subpar quality.

General representation and scope of application

The goal of the two-pipe heating system, in contrast to one-pipe wiring, is to supply the coolant to all heating devices at the same temperature. One hot coolant travels from the boiler to the batteries via two different pipelines, and the cooled water is then returned to the radiators. The two-pipe heating system’s design stipulates that both branches are connected to the eyeliners.

In two-pipe heating systems, a circulation pump is typically used to move the water. This enables you to create a branching pipeline network of any complexity to guarantee that even the most remote rooms are heated. However, the circuit can be created naturally through gravity, without the need for a pump. It is necessary to use large diameter pipes that are laid in an open manner and have a slope of at least 10 mm for every meter of pipeline length. The following benefits are associated with a private home’s two-pipe heating system:

• reliability in operation;
• efficiency due to the supply of water with the same temperature in the heating devices;
• universality, which makes it possible to lay the branches of heat supply in an open and closed way;
• ease of balancing;
• the possibility of automatic regulation of thermostatic valves;
• relative ease of conducting installation work.

The scheme’s versatility allows for a very wide range of applications where two-pipe heating can be used. These include administrative offices and production workshops, as well as civil buildings of any size and purpose.

A two-pipe heating system is a clever way to achieve efficient temperature control in a multi-story building. This arrangement, in contrast to single-pipe systems, uses different pipes to return cooler water and supply hot water, guaranteeing uniform warmth throughout the building. Because every floor has its own loop, it is possible to regulate the heating independently, which is especially important in large structures with different heating requirements. This system makes maintenance easier because problems on one floor don’t affect the heating of the entire building. It is also more comfortable and energy-efficient for occupants, which makes it a sensible option for insulation and heating projects in multi-story buildings.

About the methods of laying pipes

The two-pipe heating system’s dead end diagram is most frequently utilized when planning a private home’s heating system. A set of radiators connects two highways in turn, starting with the first and ending with the last device.

Radiator valves with thermal heads are used for automatic regulation and preliminary balancing to guarantee that each radiator uses the necessary amount of water.

Other common turning patterns, besides the dead end, are as follows:

• Associate (loop of Tichelman);
• Collector scheme of wiring.

This horizontal two-pipe heating system functions as a ring that supplies the coolant group of heating devices; it does not have first and last radiators because of passing wiring.

On the feeding line, the battery comes first in a row, and it comes last on the reverse pipeline. In other words, the coolant at the feed and in the return only flows in a forward direction, not in the direction of one another. An initial hydraulic balance is achieved in a two-pipe horizontal heating system with a passing movement because the water in the loop travels the same distance.

The two-pipe connections that link each heating device to the collector, the single distribution unit, are what give the collector heating system with lower wiring its strength. These are employed in the water heating system’s organization. The discrete installation of individual battery branches is done beneath a wooden floor or in screed. All regulation and balancing is done on a collector that has flow meters (rotameters) and special valves installed.

Modern interior design standards for homes dictate that lower wiring heating systems are most frequently utilized because they make it possible to conceal pipes into walls and floors or run them openly above baseboards. When setting up gravity networks, a two-pipe heating system with the upper wiring is required if the feeding line is situated in the attic or beneath the ceiling. After rising directly from the boiler under the ceiling, the heated coolant diverges via the horizontal pipe and passes through the batteries.

Schemes are classified into two types based on the working pressure within the network:

1. Open. At the top of the system, an expansion tank is installed, communicating with the atmosphere. The pressure at this point is zero, and near the boiler is equal to the height of the water column from the top to the bottom of the heating network.
2. Closed heating systems. Here, the coolant is given excess pressure in the amount of 1-1.2 bar, and there is no contact with the atmosphere. A closed expansion tank of a membrane type is located at the lower point, next to the heat source.

Two pipe systems can be wired vertically or horizontally. In the locations where heating devices are installed, both highways become risers that denigrate multi-story floors when designed in a vertical manner. It is distinctive that horizontal collectors located in the lower or upper portion of the house are still used to supply coolant to the risers.

Rules for the choice

In selecting an appropriate heating system, the following general guidelines should be followed:

• with unreliable power supply of the house, when the circulation pump is often turned off, there is no alternative to a two -pipe dead end circuit with the upper wiring;
• In the buildings of small area (up to 100 m ²), a dead end or passing two -pipe heating system with lower wiring will be appropriate;
• Installation of vertical risers is made in multi -storey buildings, where the layouts of each floor are repeated and radiators are in the same places;
• In cottages and wooden houses of large area with high requirements for the interior, it is customary to arrange a collector system with laying branches under the floors.

Since there are so many options, it is impossible to anticipate them all. It is advised to draw a plan of how the homeowner would arrange the batteries, write them down in different configurations, and then figure out how much the materials will cost in order to select the best option.

Independent work tips

Prior to beginning the installation of a two-pipe heating system, pipes with an appropriate diameter must be selected.

This is not hard to accomplish for a lethal network of tiny homes where forced coolant circulation is intended: a 20 mm diameter pipe is used on highways, and a 16 mm diameter pipe is used for carts to radiators. Pipes with a diameter of 25 mm will be needed for a two-story home up to 150 m²; the eyeliners stay the same.

In a collector scheme, 16 mm pipes are used for the eyeliner, and 25–32 mm pipelines, depending on the floor area, are used to line the highways leading to the collector. In all other situations, it is advised that you get in touch with design experts for assistance with the computation; they will assist you in selecting the best plan and branch size.

When installing heating yourself, you should select pipes made of appropriate materials from the following list:

1. Metal -plastic pipelines. When assembly on compression fittings, special tools are not required, only the keys. More reliable pressed connections are made by ticks.
2. Sewed polyethylene. This material is also connected by compression and press fittings, and Rehau pipes – by expanding and pulling the fixing ring.
3. Polypropylene. The cheapest option, but requiring some skills of welding joints and the presence of a welding machine.
4. Corrugated stainless pipe joins clamping fittings.

Pipelines made of steel and copper are not taken into consideration because skill and experience are needed to make heating from them. After connecting the shut-off valves and radiators, the system is assembled starting at the boiler.

Using an assessment pump, the network’s tightness is verified at the conclusion.

see also

• 27.07.2016 Calculation of gas consumption for heating a house 150 m2
• 26.07.2016 Calculation formulas heat loss at home
• 14.07.2016 Types of electric heating of a private house

Two -pipe wiring of the heating system: classification, types and types

One or two pipes may be used in the water heating system. The term "two-pipe" refers to the fact that two pipes are required for operation: one hot coolant that is fed into the radiators directly from the boiler, and another cooled coolant that is taken out of the heating elements and fed back into the boiler. Such a system can operate on any kind of boiler using any fuel. It is possible to use forced or natural circulation. Buildings that have one story, two stories, or more floors are equipped with two-pipe systems.

Advantages and disadvantages

The primary drawback of this heating system organization approach stems from the coolant circulation method: two times as many pipes are required as in the primary competitor’s single-pipe system. In spite of this, the cost of purchasing materials is only marginally higher because the 2-pipe system makes use of smaller diameter pipes and fittings, which are also significantly less expensive. The cost of materials is therefore somewhat higher as a result. In actuality, there is more work involved, which means twice as much time is needed.

Two-pipe radial and standard heating system

This drawback is compensated by the fact that on each radiator you can put a thermoregulating head, with which the system is easily balanced in automatic mode, which cannot be made in a single -pipe system. On such a device, set the desired temperature of the coolant and it is constantly maintained with a small error (the exact value of the error depends on the brand). In a single -pipe system, it is possible to implement the ability to adjust the temperature of each radiator separately, but this requires a bypass with a needle or three -way tap, which complicates and increases the cost of nullifying, nullifying the winnings in money for the purchase of materials and time for installing.

One other disadvantage of two-pipe is that radiator repairs cannot be done without the system being stopped. Although this is inconvenient, you can get around it by placing ball valves close to each heating element on the feed and return. If they’re blocked, you can take out and fix a heated towel rail or radiator. You can use the system for as long as you’d like.

To compensate for the regulatory reinforcement on each radiator, the system can be designed to

However, there is a significant benefit to this type of heating arrangement: in contrast to a single pipe, which exists in a system with two highways for every heating element, water at the same temperature is delivered straight from the boiler. Installing thermostatic heads or taps to control the flow’s intensity fixes the issue, even though the system tries to take the path of least resistance and won’t spread past the first radiator.

One more benefit is that gravity heating or forced circulation systems with smaller pumps can be implemented with less pressure loss and ease.

Classification 2 pipe systems

Heating systems of any type are divided into open and closed. In closed, an expansion tank of a membrane type is installed, which makes it possible to operate on the system with increased pressure. Such a system makes it possible to use not only water as a coolant, but also compositions based on ethylene glycol, which have a reduced freezing temperature (up to -40 O C) and are also called antifreeze. For the normal operation of equipment in heating systems, special compositions designed for these purposes, and not general purposes, should be used, and even more so, not automobile. The same applies to the additives used and additives: only specialized. It is especially hard to adhere to this rule when using expensive modern boilers with automatic control – repairs during problems will not be warranty, even if the breakdown is not directly related to the coolant.

Depending on its type, the expansion tank’s installation location

An open-type expansion tank is constructed at the highest point in an open system. Typically, it has a pipe attached to it to remove air from the system and to set up a pipeline to drain the system’s excess water. There are occasions when they can obtain warm water for domestic use from the expansion tank; however, in these situations, an automatic system must be set up and additives should not be used.

Closed systems offer greater security, which is why the majority of contemporary boilers are designed for them. Click here to learn more about closed heating systems.

Vertical and horizontal two -pipe system

A two-pipe system can be organized in one of two ways: vertically or horizontally. The majority of the time, multi-story buildings use vertical. The ability to connect radiators on every floor is easily achieved, though it does require additional pipes. The primary benefit of this type of system is the air’s automatic output, which exits through a descent valve or an expansion tank depending on its tendency to rise.

Vertical wiring with two pipes for a multi-story building’s heating system

One-story or, at most, two-story homes are more likely to use the horizontal two-pipe system. The "Maevsky" crane is installed to draw air from the system for the radiators.

A two-story private home’s two-pipe horizontal heating system (click on the image to enlarge it)

Upper and lower wiring

By the method of serving the supply, the system is distinguished with the upper and lower feed. During the upper wiring, the pipe goes under the ceiling, and from it down the feed pipe is lowered down to the radiators. The return goes along the floor. This method is good in that you can easily make a system with natural circulation – the height difference creates a stream of sufficient power to ensure good circulation speed, you only need to observe a slope with a sufficient angle. But such a system is becoming less and less popular due to aesthetic considerations. Although, if you hide the pipes at the top under the suspended or stretch ceiling, then only the pipes to the instruments will remain in sight, and they, in fact, can be highlighted in the wall. Upper and lower wiring are used in vertical two -pipe systems. The difference is demonstrated in the figure.

With an upper and lower coolant eyeliner, the two-pipe system

With the lower wiring, the feed pipe goes down, but higher than the return. The feed tube can be placed in the basement or semi -basement (the return is even lower), between the draft and the final floor and t.D. You can bring/take the coolant to the radiators by passing the pipes through the holes in the floor. With this location, the connection is the most hidden and aesthetic. But here you need to select the location of the boiler: in systems with forced circulation, its position relative to radiators does not matter – the pump will “be sold”, but in systems with natural circulation, radiators should be higher than the boiler level, for which the boiler is buried.

Different radiator connection diagram for a two-pipe system

The video shows an example of a two-story private home’s two-pipe heating system. It has two wings, and the lower kind of wiring, known as valves, controls the temperature in each of them. Because the boiler is mounted on the wall, the system has forced circulation.

Dead -end and passing two -pipe systems

A system known as Dead East has multidirectional coolant and return movement. A passing system is in place. It is also known as the "Tichelman" loop or diagram. With longer networks in particular, the latter option is simpler to balance and adjust. The system will automatically balance if radiators with the same number of sections are installed and the coolant passes through them. However, in the case of a dead end diagram, each radiator will need to have a thermostatic valve or needle valve installed.

Two-pipe systems with two coolant movement circuits: a dead end and a passing circuit

The "Tichelman" scheme must be installed even if the radiators and valves/valves of various sections are already installed with it. This is because the likelihood of balancing the scheme is higher than that of a dead end, particularly if the scheme is lengthy.

Strong screwing is required to balance a two-pipe system with multidirectional coolant movement. This valve is on the first radiator. There’s also a chance that it will have to be closed to the point where coolant won’t go there. It turns out that you have to make a decision between the two batteries because in the former case the heat transfer cannot be aligned and the battery in the latter will not warm up on the network.

Heating systems for two wings

And yet, more often they use a system with a dead end circuit. And all because the lining of the return is longer and it is more difficult to collect it. If your heating circuit is not very large, it is quite possible to adjust the heat transfer on each radiator and with a dead end connection. If the circuit is large, but I don’t want to do the loop of the “Tichelman”, one large heating circuit can be divided into two smaller wings. There is a condition – for this there should be a technical possibility of such a network construction. At the same time, in each circuit, after separation, it is necessary to put valves, which will regulate the intensity of the flow of the coolant in each contours. Without such valves, to balance the system is either very difficult or impossible.

The video shows several coolant circulation techniques and provides helpful advice on equipment selection and installation for heating systems.

Component	Description
Boiler	The device that heats water or steam to provide warmth to the building.
Pipes	Two separate pipes, one for hot water flowing in and the other for returning cold water.
Radiators	Devices connected to the pipes that release heat into the rooms.
Thermostatic Valves	Valves on the radiators that control the amount of heat released into each room.

Comprehending the complexities of a multi-story building’s two-pipe heating system is essential to maximizing both comfort and effectiveness. This system works on a straightforward but efficient principle: hot water is sent to the radiators via one pipe, and cooled water is returned to the boiler for further heating via another pipe.

A two-pipe system’s ability to keep the building’s heat distribution uniform is one of its main benefits. No matter where they are in the building, residents can always enjoy comfortable temperatures in every room because there is a constant supply of hot water to every radiator.

When compared to single-pipe systems, the two-pipe system also provides more control and flexibility. Individual radiator valves let residents customize their heating preferences based on their needs by allowing for precise temperature adjustments in designated areas.

To maximize a two-pipe heating system’s efficiency, proper insulation is essential. Insulation helps to maintain the warmth produced by the system by minimizing heat loss through walls, floors, and ceilings, which eventually results in lower energy consumption and utility costs.

To sum up, a well-thought-out and well-maintained two-pipe heating system is a crucial part of contemporary multi-story buildings. This system serves to minimize operating costs for building owners while promoting occupant comfort and sustainability through consistent heat distribution, flexibility, and energy efficiency.