Various sources are used to heat the floor. In devices that use electricity for heating, special cables are used that heat up when current flows through them. Today, several types of electric heating devices are used.
- Cable heating method ↓
- Electric heating mats ↓
- Types of thermostat ↓
Advantages and disadvantages
- Manufacturers and selection criteria ↓
- Price and reviews ↓
- Heating cables.
- Electric mats.
- Infrared heating film.
When they say "electric underfloor heating", they basically mean cable heating devices, including heating mats. This is because the principle of operation of cable heaters is the conversion of electricity directly into heat.
Heating occurs by convection of heat from a heated cable through the air. The basis of such heating includes wires of aluminum or copper alloys, laid in a certain order on the rough surface of the floor and filled with a screed.
Cable heating cores made of metal alloy have high resistance. As a result of the passage of current through them, the cable heats up.
Infrared films - This is an innovative development. Heat is transferred directly to objects with infrared radiation created by the passage of current in a special conductor. In this case, electricity is converted to heat indirectly through an intermediate step in the production of UV.
Cable heating method
There are two types of heating: resistive and self-regulating.
With the resistive method, two types of structures are used: with one residential and two.
Conductors of a single-core shielded cable are wires of nichrome, steel with galvanized surface, brass and other metals. The insulation is performed in two to four layers of PVC, fluoroplastic or silicone rubber. A protective shield made of aluminum foil or lead is placed on top of the insulation. He serves simultaneously grounding and reduces the effect of the electromagnetic field.
Core heating temperature can reach 80aboutWITH. At the same time, the insulation must withstand temperatures above 100aboutWITH. The lower the maximum design temperature for heating the core, the better it will withstand overloads during operation.
A twin-core cable consists of a heating and supply (copper) core, parallel to the first. The entire structure is protected by a metallized braid (shield) and a protective sheath.
Laying a cable with two wires is simpler than a single core. It does not require locking ends in one place. At one end of the structure, the wires are closed with a plug, at the other, the ends are placed in a sleeve and have a lead-out end for connection to the power grid.
The magnetic radiation of both veins located side by side partially cancel each other. This is facilitated by the protective screen located around them.
The cost of a two-core design is more expensive than a device with one core, regardless of the manufacturer, because it has a more complex device.
The self-regulating view of the heating device has two conductive cores. A polymer matrix is placed between them, which provides heating and transfers heat. The role of this matrix is to regulate the thermal conductivity of the conductor: if the temperature rises, the thermal conductivity decreases, at a low temperature it increases.
This design cannot overheat. It is placed directly under the finish floor. Furniture and heavy home furnishings can be placed on the floor surface in any place, without fear of damage to the coating and the heating device itself.
Electric heating mats
An improved version of cable heating are heating mats. The design is a heating cable structure, fixed in a certain order (snake) on a polymer grid.
Products are manufactured in rolls with a width of 50 cm to 1 meter and a length of 0.5 to 25 m. The width depends on the power of the device. A cable thermostat usually includes a thermostat with a temperature sensor, as well as a corrugated pipe for placing it on the floor.
In its pure form, the electric cable is sold in limited quantities. Basically, heating mats from various manufacturers are represented on the market. They are in demand, despite the fact that they are more expensive by 20-50% of the cable.
Mats are convenient in laying, have pre-calculated power, they can be cut into fragments without damaging the cable itself.
Types of thermostat
Heating systems alone cannot be used without temperature controllers (thermostats) equipped with a temperature sensor. There are varieties of thermostats designed for use in different conditions.
Among them are:
- Non-programmable type.
- Programmable type.
- Embedded devices.
- Overhead devices.
- Thermostatsdesigned for mounting on a rail in a control cabinet.
The non-programmable type of thermostat is used in small rooms: bathrooms, hallways and others. Temperature adjustment is carried out using a switch or smoothly using a resistor.
Programmable thermostats perform a wide range of tasks:
- Support the set temperature conditions.
- Enable automatic shutdown at a given time.
- They have several controlled operating modes. both in temperature and in time.
- Easily combined with the smart home system.
The use of programmable thermostats allowed the use of storage systems, involving the accumulation heat energy received during grace time tariffs and further use of stored heat with the power off heating up.
Devices are also subdivided according to the installation method, regardless of whether they are simple or programmable. Their device may provide for both a surface-mounted mounting method, and built-in into the walls.
There is also an option for installation in a control cabinet on a special DIN raildeveloped by the German Institute for Standardization and corresponding to GOST R IEC 60715-2003.
If the thermostat does not provide sufficient power, which usually does not exceed 3 kW, a magnetic starter, also controlled by a thermostat, is used. You can also use your device for each heating area.
To determine the surface temperature, temperature sensors are used that can be placed between the cable cores and in the thermostat itself.
If the underfloor heating serves as the main heating of the room, then the ambient temperature indicator is more important indicators of heating the floor surface, so in this case it is better to use a system with a built-in thermostat sensor.
If it is important to control the heating of the surface of the floor, for example, when covering it with laminate or parquet to avoid overheating, it is better to install the sensor in the floor.
At the same time, the sensor in the thermostat itself is not canceled. In humid rooms, the sensor is installed inside them, the thermostat itself must be outside the humid room.
Advantages and disadvantages
An underfloor heating system has its advantages:
- The ability to regulate temperature conditions using thermostats and sensors, which can significantly save energy consumption.
- Even heat distribution throughout the room.
- Quick heating of the floor surface after connecting the cable to the mains.
- Possibility of laying on top of previously mounted old coatings, as well as the replacement of failed sections of the system (referring to heating mats).
- Safe operation, since current-carrying cable cores are equipped with emergency protective shutdown.
- Long service life (up to 50 years old).
Cable heating also has disadvantages.
- Significant power consumption, which limits the use of this type.
- Magnetization of the surrounding area in the working field of the electric cable, although studies have shown that this statement is controversial.
Manufacturers and selection criteria
Among the huge variety of heating systems on the market, a large share belongs to German, Norwegian, American, Korean manufacturers who have extensive experience in producing such products.
Among them, the leading role belongs to Hemstedt (Germany), Nexans (Norway), Tyco Thermal Controls (USA) and others. Today, the production of underfloor heating has been mastered by many domestic manufacturers.
The main manufacturers include the company "Special Systems and Technologies" (Russia).
The market consists mainly of two-core heating designs, as well as heating mats of different capacities. When choosing, one should rely not only on the cost of the heating system, but also on the possibility of use in a particular place and under a certain floor covering.
It is worth considering the power of the heating product, calculated on the area of the room. For the calculation, they rely on the average specific power rating of the floor heating coating, which depends on the thermal insulation of the home and the additional heating option used by the system. It is in the range of 110-130 W / m2.
At the same time, the cable system should occupy up to 70% of the surface area. Under such conditions, it should have a power of 120-150 W / m2. In the accumulating types of devices, the power can reach 240 W / m2. In the case of wooden floors, the maximum power should be no more than 80 W / m2.
When choosing heating products, the nature of the finish coating should be considered. The cable method of heating the surface is well suited for granite and ceramic tiles, linoleum, laminate, parquet board.
The selection criterion is the good thermal conductivity of the coating, which is the most suitable for ceramic tiles. For other coatings, certain conditions must be met. For example, linoleum should be without an insulating layer, and the parquet is made of dry wood.
The cork and carpet are completely unsuitable for electric heating, since they are heat insulators.
Typically, any floor covering is labeled to indicate the possibility of using floor heating.
Price and reviews
The price of cable products for surface heating depends on the following factors:
- From the manufacturer and models.
- Device completeness (the presence of a thermostat, temperature sensor, etc.).
- Power kit.
- Sizes cable mat.
- Square maximum heating.
For example, the price of the “Teplolux” kit Mini MH-155 is 1.00, including a single-core cable mat, designed for an area of 1 square meter. m. and power of 155 watts is 3900 rubles.
“The electric heating method, of course, is convenient, especially in the form of a roll, but I would not bet on such heating only. And if there is a power failure? ”
“We installed such a system as an addition to the main heating of the house. Very pleased. It creates warmth in the lower part of the room, legs are always warm, and in the kitchen and in the bathroom it’s generally comfortable! ”