How to choose pipes for underfloor heating?

When starting the idea of ​​creating an efficient heating system in a residential building, it is important to determine the goals and objectives that heating equipment will solve and how suitable certain consumables are for a given situation.

Recently, there has been a trend of transition from traditional radiator heating to floor heating equipment. This method of heating, as shown by statistics and practical application, is much more efficient than all existing heating options. Heating of a water circuit laid in a concrete screed or in a wooden structure is carried out due to the circulation of the coolant. The supply of warm water can be carried out through the operation of an autonomous boiler or using a centralized supply of coolant. The design is based on water pipes used for the main work of a warm water floor. From which pipes the heating circuit lines are made, not only the efficiency of the home heating system, but also the comfort and safety of the inhabitants of the house depends. What materials are needed to install underfloor heating? What material can the pipelines of the heating system be made of and how to correctly calculate the required number of pipes for the project.

We will try to find answers to these questions that will help you successfully cope with the task.

How important is the correct choice of pipes for underfloor heating

The water heating system, when the channels through which the coolant circulates, are laid on the floor and warm water circulates through them, is at first glance simple and understandable. Another thing is how to carry out the installation of the pipeline on the prepared surface, correctly lay the loops of the water circuit, ensure a strong connection of the pipes and, accordingly, connect the finished lines to the distribution equipment. There are many questions here, to which you should look for the right answers and, accordingly, make competent engineering decisions.

Different tasks can be assigned to a warm floor at home. Some prefer to use a similar heating option in limited areas of residential premises. Others set large-scale tasks for underfloor heating — heating the entire living area of ​​​​the object. The pipe for the warm floor in this case plays an almost decisive role. The quality of the pipe, its strength and reliability are the main conditions for the efficient operation of the heating system, especially when it comes to the long length of the water circuits.

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Currently, the market for consumables for heating systems is quite diverse. In the distribution network, you can see consumables specially designed for installation in the floor, differing in the method of manufacture and composition. At first glance, only the cost of materials can be decisive in terms of choice, but in fact, the issue of choosing a water line should be taken more carefully. There are a number of criteria according to which consumables for underfloor heating circuits should be selected.

Among the most important criteria, the following aspects should be noted:

• the cross section of the water channel should not exceed 16 mm, taking into account the thickness of the screed;
• all consumables must be marked accordingly, designed for use in low-temperature heating systems;
• the ability of the pipe to withstand significant drops in the working pressure of the coolant in the system;
• technological stability of the material to high temperatures;
• resistance of the pipeline to mechanical stress and the reaction of the material to heating;
• ease of use, including routine and emergency repairs.

Important! When buying pipes, pay attention to the name of the company, the manufacturer. A well-known brand will become for you a guarantee of the quality of consumables, the reliability of the entire heating system.

In most cases, today preference is given to working with metal-plastic and polymer pipes, which are based on cross-linked polyethylene. Such materials have already been tested in practice and serve as the main elements of pipelines of heating systems for more than one year and in a variety of conditions.

If desired, and with financial capabilities, you can bet on copper pipes, but in this case, the warm floor will become golden for you, in the truest sense of the word. Underfloor heating, in which the pipe is the main working element, can have a different length. Doing floor heating throughout the house, using expensive consumables, is a thankless task. Copper piping is suitable for installing a water circuit in a bathroom or kitchen. Using copper lines for other purposes is a waste of money.

Each type of main water circuits used in floor heating systems has its own technological characteristics. Accordingly, pipelines in such a situation have different technical parameters and differ in installation conditions.

For reference: in practical terms, plastic products are most often used. Up to 90% of all water floor installations are made of polymeric materials. The reason for such popularity and prevalence is that this consumable is affordable and convenient from a practical point of view.

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What are the options when choosing the optimal consumables for underfloor heating? Let’s figure it out in more detail

Option one — use copper pipes

In this case, it is not worth dwelling on this option for a long time. It has already been written above that copper for a warm floor is an expensive pleasure. Here, not only the cost of consumables is taken into account, but also the complexity of installing the entire heating system. Laying pipes made of copper is carried out using special equipment and in compliance with a certain technology, so it will not be possible to make this heating option on your own. Despite the high cost of copper pipes, and the costs associated with installation, such products have high technological characteristics. Copper conducts heat well and is highly resistant to corrosion.

Option two — metal-plastic pipes

Unlike copper pipes, a good and convenient option for underfloor heating will be the use of metal-plastic heating water circuits. This material is quite common today and is quite popular.

For reference: metal-plastic pipelines have high efficiency and are durable. Having a layer of aluminum foil inside, metal-plastic pipes have a relatively high thermal conductivity. Due to the inner and outer layers of polymers, the products have the necessary strength and good resistance to corrosion processes.

The cost of such a consumable is considered acceptable, so many consumers rely on metal-plastic. The choice of what material, metal-plastic, copper, or polymer materials is used for the pipe used for your underfloor heating, which one is better, which one is worse, is up to you. All options have the right to be sold and do not differ in anything cardinal, except for the price. The following aspects are very important to pay attention to:

• metal-plastic pipes are able to withstand hydrodynamic, thermodynamic and mechanical loads;
• consumables are easy to install and in the process of further maintenance;
• products have a long service life.

To date, manufacturing companies mainly produce a five-layer metal-plastic pipe, in which three layers are basic, and two are adhesive, i.e. binders.

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The inner layer is the main one, being responsible for the technological parameters of the pipe: working pressure and coolant temperature. The peculiarity of this layer is that it is made of cross-linked polyethylene by extrusion. The thickness of aluminum foil can vary between 0.2-2.5 mm, depending on the main diameter of the pipe.

Due to the multilayer nature of metal-plastic pipes, they withstand mechanical and dynamic loads, which is important for the successful installation of underfloor heating pipelines. Water circuits are laid in loops, in the form of a snake or a spiral, therefore, during the installation process, the water loop has many bends and turns.

The third option is polymer pipes, made of cross-linked polyethylene

Copper or metal-plastic, which pipe is better for underfloor heating equipment, cannot be answered unambiguously. The answer to this question is the popularity of the third option, the use of polymer pipes. Products are made of cross-linked polyethylene. The amorphism and chemical neutrality of polymers provides water loops made from it with excellent resistance to high temperatures. The design temperature parameters at which polymer pipelines can be used make it possible to work with a coolant with a temperature of 95⁰C. All polymer consumables have a special PN marking.

On a note: For underfloor heating, a special marking PN 10 is used. In a pipeline with this marking, the working pressure of the liquid should not exceed 10 atmospheres. For products of the PN10 brand, the recommended maximum coolant temperature is 55⁰FROM.

The strength of the material is achieved through production technology. Cross-linked polyethylene pipes for underfloor heating should have a cross-link density in the range of 65-80%. Depending on the surface treatment, the cross-link density depends. The strength and tightness of the connections of all loops into a single heating complex is ensured by special fittings. Using a welding machine, you can successfully make a water heating circuit of the required length. The length of the water circuit pipe for underfloor heating is one of their main technological aspects of the implementation of the «warm floors» project. Unlike copper and metal-plastic pipes, polymer consumables allow you to build heating loops of the maximum allowable length (up to 120m).

The only drawback of this variant of consumables for heating systems, heating floors, is a rather large bending radius of the pipe (8 diameters or more). In other words, with a channel diameter of 20 mm, the distance between the two loop lines will be at least 320 mm, which significantly affects the degree of heating of the concrete screed and flooring.

The fourth option, as an alternative — PEX pipes

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The cheapest way to solve water circuit installation problems is to use PEX pipes. The cost of such consumables is low. Such material perfectly gives off thermal energy to the floor covering and is designed for long-term operation. The only argument put forward by specialists in warm water floors when working with this material is the need for rigid fixation of the pipeline at the time of installation. If you neglect this remark, your pipe can easily straighten up and then the entire layout and layout of the pipeline will be violated.

In order to avoid such troubles, it is necessary to lay the heating circuit from these materials on a special substrate, in which cells for the highway are provided.

How to calculate the optimal pipe consumption for underfloor heating

If the situation is quite clear with the materials from which pipes for floor heating are made, then with the amount of consumables required for the equipment of the “warm water floor” heating system, many questions arise. Which pipe to choose for installing a warm floor, and in what quantity, special calculations will help.

Material consumption is determined at the design stage of the heating system itself. It is necessary to proceed from the calculations that the maximum allowable length of the water circuit should not exceed 120 m. One loop of the water circuit must be made from one single piece of pipe.

Important! The underfloor heating system does not allow the laying and installation of pipelines with multiple connections. The only exception may be fragments inserted into the body of the circuit during an emergency leak during the repair process.

On sale there are pipes twisted into bays. As a rule, one bay is enough to cover the floor in a heated room with an area of ​​20 m². If the total area of ​​​​heated premises is known to you, then you can calculate the approximate footage of the water main. When calculating, take into account the pipeline pitch, i.e. the distance between adjacent turns of the loop. The maximum allowable step size is 35 cm. No more, less please if you want to create a higher temperature in the room.

Conclusion

If you want to do everything competently and at the highest level, invite specialists to install the heating circuit. You can independently perform work on laying underfloor heating in small areas. The correct calculation of the flow of water lines will provide you with significant cost savings.

Do not neglect the importance of design work for the equipment of the heating system. The prepared project will ensure normal installation, without excesses and failures. The result of competent work will be a full-fledged heating system in your home, designed for long-term operation.