With the high level of development of modern technologies, few people use archaic stoves to heat greenhouses: they are replaced by new devices that are able to efficiently and economically prepare the soil for planting plants and maintain the desired temperature during the growing process. The article will focus on one such technical innovation - a self-regulating heating cable.

Cable heating benefits

The advantages of thermal cables are obvious both in the use and absence of the need for maintenance, and in the amount of the crop obtained with their help. For greenhouses measuring about 4 × 12 meters, this solution will be optimal from any point of view.

Advantages of this heating method:

1. Profitability. Low power consumption is provided by regulating its consumption by a semiconductor matrix. In the same way, the system is protected from overheating.
2. Safety. Water, foreign matter in the soil (branches, debris, etc.), overlapping cables, accidental contact will not disable the system and will not have any effect on humans, animals and plants.
3. Convenience of installation. Arrangement of heating elements is carried out only once, after which they can only be turned on / off if necessary. The appearance of the greenhouse does not deteriorate - the coolants are safely hidden in the ground.
4. Simultaneous use multiple systems. In one room you can grow plants with different requirements for soil temperature. For this, heating cables of various sections and capacities are laid.

As for plant growth and productivity, here the benefits of using a thermal cable are undeniable:

• early or continuous soil heating;
• the possibility of year-round laying of seeds and germination of seedlings;
• providing plants with ideal growth conditions in any weather outside the greenhouse;
• cultivation in a cold climate of thermophilic crops;
• the ripening period of the crop of even the same plant can be regulated in different parts of the room;
• extension of fruiting.

Did you know? The world's first greenhouse (more precisely, a winter garden) was created in 1240 in Cologne by gardener Albert Mangus. However, the leaders of the Inquisition did not appreciate the beauty created by the hands of this man, and accused him of witchcraft.

Types of heating cables for greenhouses

Heating cables are resistive or self-regulating. Resistive is much cheaper, but this is where their advantages end. Targeted equal exposure of resistive cable to soil with initially different temperatures leads to overheating or insufficient heating.Resistive cable Self-regulating cables are free from such drawbacks, as they are capable of metering the heating of the earth separately in each section. Despite the high cost (almost three times more than resistive), they quickly pay off due to the distribution of energy consumption and simple maintenance of the system composed of them.Self-regulating cable As for the heating elements used in two different systems for cable heating of the earth in a greenhouse, an active core (single-core or multi-core) is used in resistive wires, when electricity passes through which heat is released into the surrounding soil. Self-regulating thermal cables consist of two carbon conductors separated by a semiconductor material. The semiconductor, due to its non-linear characteristics, changes the resistance depending on the temperature of the soil in a certain area and gives a signal for the necessary heating.

Laying the cable heating system

Profitability and efficiency of heating directly depends on the quality of cable laying.

Important! The system and the soil need to “heal” for some time (1-2 days), after which you can start testing and planting seeds or seedlings.

The heating system is installed in the following order:

1. Remove soil to a depth of about 50 cm.
2. Pour a layer of fine sand - 5 cm.
3. Lay a layer of foam (foam or other heat-holding material) - up to 15 cm.
4. Lay a waterproofing gasket - a dense plastic film.
5. Pour another layer of sand - 5 cm.
6. Lay a prefabricated welded metal mesh with small cells, treated with anti-corrosion agents.
7. Run the cable in the form of a snake in increments of 20 cm. For mounting, you will need plastic clamps, insulation or mounting tape.
8. Pour and compact the sand layer - 5 cm.
9. Cover with a stainless steel or thick plastic mesh 1.5–2 mm thick.
10. Lay a layer of fertile earth - up to 40 cm.
11. The temperature control sensor in the moisture-resistant tube should be located a meter above the ground.

Operational Features

After overcoming difficulties with installing the system, its operation is very simple. How many degrees should be set on thermostats in different areas, the gardener decides depending on the requirements of the culture that will be grown there. If it warms up to the indicated temperature, the sensor will work and the line will turn off. When the soil cools down to the set value, the self-regulating cable will again begin to heat the ground. This approach allows you to save a significant amount of electricity - up to 30%.

The peak period for using the heating in the seasonal greenhouse is from March to May. During the last weeks of spring, heating is used to protect against night frost on the soil. In autumn, it makes sense to turn on the system so that vegetables, the fruits of which did not have time to ripen, still manage to finish bearing.

Important! Year-round heating must be carefully planned in advance. Every nuance is important here - from the vagaries of planted crops to the need for a backup power source in case of a sudden power outage.

Possible problems during use

When using the thermal cable, problems can arise - some of them can temporarily disable the heating system or harm living creatures:

1. Mechanical damage. A mesh made of thick stainless steel or plastic, placed when laying the cable under a layer of fertile soil where crops will grow, will help prevent damage to the current-carrying component by hand garden tools or agricultural technology.
2. Electric shock. In case of violation of the operating rules of any electrical installation, a person may be shocked - a thermal cable is no exception. All elements of the heating system must be reliably grounded and protected from unauthorized persons, children and animals.
3. Malfunctioning devices or the entire system. The heating cable and its control system can fail for various reasons - short circuit, breakdown of the temperature controller or temperature sensor, voltage drops in the supply network, etc.

The consequences of any problem can be very diverse. To avoid emergency situations, it is necessary to carefully approach the installation and operation of heating. Whenever possible, it is important to duplicate the regulators and sensors as backup, to constantly monitor the network voltage and soil temperature.

Did you know? Most of the greenhouses in the world are in the Netherlands - 105 km², which is almost commensurate with the territory of Liechtenstein. Moreover, most of these buildings are covered with traditional glass, and not with newfangled polycarbonate.

Using a self-regulating heating cable in a greenhouse is an excellent solution for growing plants and harvesting without much hassle - for many years to come. It is only necessary to responsibly approach the installation and application of this relatively new technical solution.