How to choose a heat exchanger for underfloor heating

Principle of operation

The main element of heat transfer fluid. Liquids flow counterflow through the channels created by the corrugated plates that form the channels. Wall corrugated layer, due to high flow velocity begins to gather turbulence. Each medium advances on the same plate, but on different sides of it, to avoid mixing. All plates of the heat exchanger are the same and it is as easy to install as a welded heat exchanger. Thanks to this device forms a kind of package, in which there are 4 manifolds, they are intended for inlet and outlet of different media. All plates except the outermost (first and last) take part in the heat exchange.

Having even the lowest values of hydraulic resistance, the heat transfer can be increased by a thin flow and turbulence. Both turbulence and fine flow clean the plates from unwanted and even the most stubborn fouling.

choose, heat, exchanger, underfloor

Can you use heat exchangers in Floor Heating?

Rear and front plates have openings that connect to the piping and produce heating media. Pipes can differ in the method of connection (for example, there is a type with GOST 357 thread and with GOST 2815 thread). Both depend on the type of device. Heat exchanger plates that are placed in parallel create channels. Passing all the channels the medium exchanges and leaves the equipment. This means that the plates are the most important element of the whole heat exchanger. They are only 0.5 mm thick and are cold-formed from stainless steel. A temperature-resistant rubber is installed between the plates, which makes the ducts airtight. Inlet and outlet holes are reinforced with a special gasket and rings, front and back, respectively.

The choice of the heat exchanger is based on its operating requirements. The higher they are the more plates are needed. It is the number of plates that determines the overall efficiency.

What the heat exchanger is for?

Consider the plate heat exchanger is not dismountable. There are four outlets on the body, i.e. two circuits. The device divides the streams by pressure, temperature, etc. д., Can be used for cooling, however, we need it for heating to ensure proper connection of underfloor heating. On one circuit is connected to this system, and on the other. CHP. Direct connection of water underfloor heating to the central heating system can be associated with the risk of rapid failure of the underfloor heating, since the heat transfer medium of CHP is characterized by high temperatures, high pressure, here also special chemical reagents and a lot of debris. All these factors clearly will not contribute to the service life of underfloor heating.

Thus, the heat exchanger allows you to create a home standalone floor heating system with uncontaminated water and optimal pressure. On one side of the plate goes dirty water from the CHP with high pressure, and on the other. clean water from our autonomous system with low pressure. Such a plate provides a clear hermetic separation, quality heat transfer, mixing of the flows is completely excluded. The number of such thin plates determines the power characteristics of the heat exchanger.

Types of models

Devices differ in the way they are installed. And this directly affects the efficiency of the entire system. Very often the boiler design is used, which already has a heating coil inside. Heat loss in such devices, almost to zero. And for productive work requires only a competent adjustment.

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External designs are much less productive. Because their position does not allow to warm up the coolant well. But they are used where there are no individual heating boilers. For example, in homes that use centralized heating.

Techniques for underfloor heating must be energy efficient, easy to operate and maintain. Models are distinguished by the type of fuel on which the boiler works. Consider 4 popular types of units.


Modern equipment operates on both mains and liquefied (cylinder) gas. The body of the equipment is made of cast iron or steel. The first varieties are very large, heavy and expensive. The cost is recouped by easy repair and durability. The latter types are light in weight, affordable and do not take up much space during installation.

Maximum efficiency of standard gas boilers begins at a temperature within the range of 70-90 C. The underfloor heating system operates within the limits of 55-60 C. If you set the parameter at 55 C on the equipment, the performance drops. In “low” mode, the efficiency of the equipment is reduced to 85-80%.

Low-temperature operation provokes the formation of condensation on the parts of the gas boiler. Constant moisture negatively affects the life of the device. The design can be upgraded by connecting simultaneously with the floor heating radiators.

To work in the underfloor heating system provided separate equipment. condensing boilers. These models have a low-temperature capacity of 92-100%. The equipment is additionally fed from the condensate that is formed.

Gas boiler must be installed in a separate non-residential premises. Ceiling height in the boiler room should be at least 2.2 m, and the volume of the room. 7.5 cubic meters per piece of equipment. The equipment is placed 10 cm from the walls, plastered with noncombustible building materials. Openings in the space are necessary for the flow of air.


Apparatus, working from the network. the best option for a warm water floor. Boiler quickly converts the electricity into energy. Automatic devices are easy to set up and operate, ideal for residential and commercial premises. The operator can make adjustments remotely. According to the type of heating element there are:

The equipment is ready to use, the owner does not need to purchase additional consumables. The package often comes with an expansion tank with a pump. Compact, lightweight unit is easy to install. The design has no open flame, so it is installed in any room.

choose, heat, exchanger, underfloor

Electric boiler for water floor heating is designed for low-temperature operation. To heat a small room, the circuits of the floor equipment are immediately connected to the technique. In a large-sized cottage, it is additionally necessary to install a mixing and distribution unit.

For electric boilers there are strict requirements for the network. The unit operates on dedicated single-phase lines, the voltage of which is 220 V. For safety it is necessary to install an individual automatic circuit breaker (ASB) and grounding.

Solid fuel

The principle of work of a boiler for a warm floor on solid fuel reminds coal (wood) furnace. Burning of raw materials inside the construction occurs without access of oxygen. As a result, gas is released, which heats the heat carrier.

Solid fuel boiler does not work at low temperatures. As the degree decreases, condensation builds up on the metal walls, growing into a thick plaque. Soot does not allow the equipment to productively burn fuel.

For such models to function with the maximum efficiency, it is necessary to maintain the limit of 80 C. To protect water pipes of a warm floor from boiling help buffer tank. The excess energy is stored in the heat accumulator. With the help of mixing nodes as needed the system takes away the necessary volume.

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Solid fuel boilers with output of less than 360 kW don’t need boiler rooms. The appliance can be installed in any room except for the bedroom. A solid foundation of heat resistant material is required under the base. Distance from walls. 30 cm.


Operating principle of liquid fuel boilers resembles the one of gas models. In the process of combustion, the diesel fluid turns into a volatile substance that warms the coolant. Advantages of the technique:

choose, heat, exchanger, underfloor

The equipment is fully automated, which eliminates human intervention in the work. A pungent smell is the main drawback of the models. Because of the heavy chemical odor boiler for water floor heating put in a separate non-residential room (boiler room).

Installing the heat exchanger

Mounting is most often done vertically. The diameter of the connection, size and power connection of the water floor heating to the central heating can be different in different devices. We want to pay special attention to connection diameters. The power is better to take with reserve, because this parameter does not correlate with the size, the difference can be only a few centimeters. This increases the inertia of the heat sink. This is especially true if the temperature from the heating plant is not too high, for example, if it is seventy degrees or less.

After the floor heating distributor is installed, a pump with a three-way valve is assembled on it. Next, the installation of the electric boiler (for off-season use), including the necessary attachments. That is, first the heat exchanger supply from the boiler is connected, then the tees are cut in, the distributor is connected to the valve, the thermometers are installed and the expansion tank is installed in the most convenient place, for example, you can do it under the sink. It is necessary to carry out the installation in such a way as to ensure easy access to all equipment.

Watch a detailed video on how to connect water floor heating to central heating through a heat exchanger:

If the scheme was installed incorrectly, then the consequences can be negative, so the errors should not be allowed in any case. It is better to entrust this work to experienced professionals who are aware of all the possible nuances.

LEAVE A REQUEST and our expert will help you choose the equipment

Before you pick up plate heat exchangers, it is necessary to make a calculation of the necessary heat exchanger apparatus. The calculation of the TO involves knowing many of its characteristics:

1) DHW connection diagram;

2) heat load, in Gcal/hour;

3) information about the heating medium:

  • inlet temperature (for winter/summer), in C;
  • Outlet temperature (winter/summer), in °C;
  • flow rate of the medium (in case of lack of load data), in m3/hour;
  • pressure loss, in atm (allowable).

4) information about the heated medium:

  • inlet temperature (for winter/summer, in °C);
  • outlet temperature (for winter/summer, in °C);
  • flow rate of the medium (if no load data is available), in m3/h
  • pressure loss in atm (allowed).
  • 3. Information about the heating medium: pressure drop (permissible) atm; power reserve (surface), in %.

We select and calculate online plate heat exchangers for hot water, heating, swimming pool, boiler room and other needs. You need only to leave an application on our website and describe your requirements and wishes.

Plate Heat Exchanger Calculation

Plate heat exchanger calculation is a technical calculation process designed to find the desired heating solution and implement it.

Heat exchanger data needed for the technical calculation:

  • type of medium (e.g. water-water, steam-water, oil-water, etc.).)
  • heat load (Gcal/h) or power (kW)
  • Mass flow rate of the medium (t/h). if the heat load is not known
  • Temperature of the medium at the heat exchanger inlet C (hot and cold side)
  • Temperature of the medium at the outlet of the heat exchanger С (hot and cold side)
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To calculate the data you will also need:

  • Technical specifications (TU), which are issued by the district heating company
  • From the contract with the district heating company
  • From the terms of reference (TOR) from the head of the Department of Energy of the Ministry of Energy of the Russian Federation. engineer, technologist

What do you need the heat exchanger for??

Consider the plate heat exchanger which is not dismountable. There are four outlets on the body, i.e. two loops. The unit separates the fluids by pressure, temperature, etc. д., Can be used for cooling, however, we need it for heating, to ensure the correct connection of the underfloor heating. One circuit is connected to this system and the other to the CHP unit. Direct connection of water underfloor heating to the central heating system can be associated with a risk of rapid failure of the floor heating, since the coolant is characterized by high temperatures, high pressure, there are also special chemical reagents and a lot of debris. All these factors clearly will not contribute to the service life of the underfloor heating.

Thus, the heat exchanger allows you to create a home standalone floor heating system with uncontaminated water and optimal pressure. On one side of the plate comes dirty water from the high-pressure cogeneration plant and on the other side clean water from our low-pressure autonomous system. Such a plate provides a clear airtight separation, quality heat transfer, mixing of streams is completely excluded. The number of such thin plates determines the capacity characteristics of the heat exchanger.

Heat exchangers for underfloor heating. types, description, prices

Heat exchanger for underfloor heating is a device that connects pipe circuit to the main heating system for heating the floor surface. With the help of a heat exchanger, heat energy is extracted from the coolant from the boiler or central heating system and transferred to the heated medium with its further supply to the underfloor heating system.

  • Brazed is the most demanded type in this task on private objects, because it is compact and universal. Represents a block of metal plates brazed between each other by copper solder in a vacuum environment. Our catalog includes brazed pieces with connections of different diameters and types (thread, flange).
  • Collapsible has an important advantage. it can be dismantled for maintenance and increased capacity, and put back together. You can replace the internal rubber plates and gaskets with new ones.

Most often, the system of underfloor heating is in demand among private customers, who organize it in their private houses and at pre-house territories, but given the increased level of comfort with this system is more and more often implemented in industrial buildings and areas. The company “TeploGarant” is a major supplier of modern heat-exchange equipment of various modifications and offers to buy a heat exchanger for underfloor heating of any area, both in closed and open areas. for heat exchangers underfloor heating we have the lowest in the market, we also provide delivery and favorable conditions with an individual approach to any client.

Look for where to buy a heat exchanger as profitable as possible?

Contact the experienced specialists in “TeploGarant”

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