Single-core and double-core cables for underfloor heating installation look almost the same and generate heat. However, these similar heating systems have significant differences that affect the installation and performance of underfloor heating. When choosing a cable for self-installation, you will need to take this difference into account.
Functional differences between single and two-core cables
In 2 cases only one core acts as a heating element. The second wire in the two-wire version performs a current-supplying function. The fundamental difference between these heating systems lies in the way of connection and installation. However, along with the laying technology, other factors must be taken into account.
Features of single core cable
Warm floors of this type create a rather powerful electromagnetic field around them, which, with permanent exposure, negatively affects human health. The shielding part of the shell only partially absorbs electromagnetic waves. Therefore, this heating method is undesirable for residential premises. The optimal area of application of a single-core cable is in industrial facilities.
In residential premises, it is advisable to use single-core cables for heating those places where people spend little time. These are mainly hallways, loggias or heated balconies. In private homes, they are often used to combat stair icing and heating utility rooms.
Features of the two-core cable
After the appearance of this heating system, the problem of the harmful effects of electromagnetic waves was eliminated. Both cores of the heating element create magnetic fields, but they cancel each other out. Thanks to this feature, the electromagnetic background in rooms is close to natural. Two-core cables can be safely used in residential and office premises – they will not harm your health.
Warm floor cable Rexant Standard RND-100-1500
The power characteristics of this type of heating system are better than that of a single-core cable. However, in this case, it must be borne in mind that the total thickness of a standard two-core cable is greater. This means that when it is laid, the rise of the floor increases. In some cases, due to this feature, you have to choose a single-core cable.
Two-core self-regulating cables deserve special attention. They change the intensity of heating, the rate of which depends on the ambient temperature in the room. Such warm floors are very convenient for use in rooms with a large area. They are ways to change the intensity of heating in different areas, which allows you to evenly distribute heat over the entire area of the room.
Sometimes, in the selection process, the marking applied to the cable sheath helps to orientate. It allows you to check the characteristics provided by the seller. The code system is standardized and used by different manufacturers. The series allows you to determine the type of cable:
single-core – ISM or ISK;
two-core – IP;
self-regulating – IL.
Warm floor cable Rexant Slim RNB-30-370
The marking contains information about the maximum operating temperature, heating braid and the total cross-section of the conductors. Two-core cables are divided into the following modifications:
IPS – cores with a total cross-section of 3 mm can withstand temperatures up to 425 ° C, their braid is insulated with mica and fiberglass, they have an outer casing made of aluminum;
IPH – the calculated maximum temperature is about 285 ° C, the cores have a diameter of up to 2.5 mm and are insulated with fiberglass and mica, fluoropolymers are used as the outer sheath;
IPMM – the total cross-section of the braided cores is 2.5 mm, the operating temperature is within 200 ° C;
IPL – heating braid covers each of the cores with a total cross-section of 1.5 mm, operating temperature up to 200 ° C.
Self-regulating cables also have different maximum temperatures, and also differ in cross-section:
ILS – 200 ° C (up to 12.5 mm in height);
ILH – 150 ° C (up to 12.5 mm in height);
ILM – 100 ° C (up to 15.6 mm in height);
ILL – 85 ° C (up to 10.5 mm in height).
The insulating sheath of cables can be made of different materials and are marked as follows:
C – thermoplastic;
CF – fluoropolymer;
ST – heat-resistant.
The presence of the letter S indicates the additional use of the silicone shell.
When choosing a heating system, the installation technology is of fundamental importance, which directly depends on the number of cores in the cable. The systems have a lot in common:
both types of underfloor heating must be filled with a screed or completely covered with tile adhesive;
single-core and two-core cables can be connected to the Smart Home system .
However, there are also many differences in the styling technology. They must be taken into account first of all.
Features of laying a single-core cable
Installing a single-core cable is more difficult than laying a two-core cable. It is better to hire experienced specialists to carry out the work. After all, both ends of the cable must be accurately brought to the place of their connection to the thermostat. This requires accurate calculation and a firm hand when laying. With self-installation, inexperienced craftsmen often make mistakes, which subsequently negatively affect the operation of the heating system and can cause its premature breakdown.
Features of laying a two-core cable
When laying heating elements of this type, almost jewelry precision is not required. After all, only one end is connected to the thermostat. That is, in this case, the circuit does not need to be closed. Installation of a two-core underfloor heating is not so time-consuming and difficult, therefore, if you have basic skills, installation can be done on your own.
Which cable can be laid without a tie
One of the main disadvantages of cable underfloor heating is the need to fill the screed. This procedure makes styling more difficult:
delays the time of work;
requires additional costs;
increases the load on the subfloor.
Monolithic screed makes it impossible to repair cable heat-insulated floors. Therefore, manufacturers have long been working on creating a cable heating system that can be installed without a screed. It should be a complement to film floors. At the moment, they are ready to offer different solutions to the problem.
Warm floor film Rexant Optima 150-1
Standard cable mats also require screed to be poured or, at a minimum, the use of glue when laying the tiles. However, in addition to these, thin mats have been developed that can be installed directly under the floor covering. They have a heat-insulating layer and a shock-absorbing underlay for laminate or parquet.
Mats have also been developed that are suitable for dry installation with linoleum, carpet, PVC tiles. All heating mats of this type have one feature in common – when they are equipped with heating elements, manufacturers mainly use ultra-thin single-core cables.
Today, dry-mounting mats are produced, which can be connected to each other using built-in connectors. Such mats allow you to assemble a system for heating rooms with a large area according to the principle of puzzles. For installation, it is enough to choose rugs with the most approximate dimensions.
Warm floor cable Rexant Classic RNX -2.5-375
Installation of a warm floor on a dry one can be performed without ready-made mats. For this procedure, you will again need ultra-thin single-core cables. They need to be used in conjunction with additional elements:
connectors with protection class IP X7;
rubber coated upper protective mat.
The resulting multi-layer cake is an enlarged copy of the heating mats for dry installation. The separate method of laying the heating cable system is more economical than using ready-made rugs.
Rigid base for underfloor heating
The function of the tie can be performed by special panels with grooves for cable laying. They are specially designed for dry installation of underfloor heating. The design of such panels provides the necessary rigidity when installing laminate and parquet boards.
Additional elements for installing underfloor heating
The procedure for choosing a warm floor is not limited to the search for heating elements. The heating system also includes:
wires for connecting to the network.
They are necessary for completing both single-core and two-core floor heating. Ready-made kits are often on sale, but more often heated floors and auxiliary elements are sold separately. Therefore, this point must also be taken into account when choosing a system and purchase the most suitable components.
So what should you choose?
As this material has shown, each of the cables has its own pros and cons. Two-core cables have more advantages. They are more practical and do not require the involvement of specialists for styling. However, single-core underfloor heating also has an important plus – the possibility of dry installation. To simplify the selection procedure, we recommend using the comparison table.
Single core cable
Electromagnetic radiation There is Weak
Special skills required for styling Yes (self-assembly is possible with practical skills) You can do it yourself
Average service life 5 to 15 years old Up to 25 years old
Rated linear power Up to 28 W / m Up to 32 W / m
Possibility of installation without pouring the screed (dry) There is Limited due to oversized cable cross-section
Self-regulation function No There is
Sectional shape Round Rectangular and sometimes round
Two-core cables are optimal for residential and office premises cluttered with furniture (in this case, it is better to give preference to underfloor heating with a self-regulating function).
The dry-laying facility for certain types of single-core cables should be used with caution. If installation is required without pouring the screed, it is advisable to consider the option of laying the IR-film . It is recommended to use a single-core cable for technical needs – heating pipes, steps, roof de-icing systems.