Underground greenhouse thermos: technology, reviews

Probably everyone who grows products for their table, and even more so for sale, would like to have this opportunity all year round and at minimal cost. Thanks to the technology of building a winter thermos greenhouse, this has become possible. Moreover, even in those regions where the cold season is pronounced and abounds in precipitation. Thanks to successful results and positive reviews, the thermos greenhouse is becoming more widespread throughout the world. Its design is being finalized and adapted to the conditions of a particular area.

What is an underground greenhouse and who invented it?

The main feature of such a greenhouse is the location of its main part in the ground. From above, there is only a dome that retains heat and transmits sunlight (its shape depends on the conditions of a particular area and can be gable, single-pitch and arched). The depth in the earth also depends on the climate of the region, the guideline is the level of soil freezing. In the middle zone of Russia, the optimal indicator is 2-2.5 meters. Due to the underground location, the thermos effect is achieved.

The principle of constructing pit greenhouses was known at the beginning of the last century, but the author of the patented new-generation thermos thermos is Anatoly Patiy, a Ukrainian engineer and breeder. He achieved stunning results in the cultivation of not only local crops, but also exotic fruits, harvesting in excess of quantity and frequency even harvested in natural conditions for their growth. Instead of 3-4 times a year, habitual for picking citrus fruits in Africa, he received 9 full-fledged crops, and the number of lemons grown by him turned out to be three times as much. Bananas ripening in nature during the year were obtained by A.V. By pushing for six months. Thanks to these indicators, the payback of the greenhouse is significantly accelerated, amounting to no more than two years (with an industrial approach to growing), in contrast to the seven-year average for standard greenhouses.

Benefits

Currently, the underground greenhouse is one of the most successful indoor equipment options. What are its virtues?

• The main advantage of the thermos greenhouse is a unique energy-saving technology that allows not only to save heating costs, but also to maintain the temperature balance. In summer, the design helps to avoid overheating, and in winter, even in severe frosts, a positive temperature is maintained without additional heating (to create the microclimate necessary for plants, of course, heating will be required, but the costs will be several times less).
• Year-round possibility of growing in it the most diverse, almost any crop.
• Strength and durability - the small elevation of the structure above the ground makes it resistant to strong winds. When using quality materials for construction, the service life is at least 15 (and is claimed even up to 50) years.
• Shortened payback period.
• The naturalness of the conditions. The technology of the greenhouse-thermos allows you to create a microclimate close to natural.
• High light transmission. The materials used for coating allow penetration of the maximum amount of sunlight, while protecting plants from excessive ultraviolet radiation.
  

The disadvantages of the pit greenhouse

Like any other construction, the underground thermos greenhouse has its drawbacks. However, their negative impact can be significantly reduced, knowing about the negative factors in advance and providing for the arrangement of the structure. Both adverse moments are associated with the location of the main part of the greenhouse in the ground:

• Excessive humidity. A large amount of precipitation, their accumulation in the soil leads to the fact that the humidity increases and indoors. With this development of events, mold, moss, pathogenic bacteria and fungi may appear. To avoid such troubles will allow the supply and exhaust ventilation equipment.
• Labor input or financial costs. Since the foundation of the thermos greenhouse is a pit with a depth of at least 2 meters, digging it with your own hands can become quite difficult. If you plan to build a large-scale construction, most likely, you will have to use special equipment, for the hiring of which significant financial resources will be required (which, with proper planning of further activities, will return pretty quickly).

DIY greenhouse thermos

The construction of this type of greenhouse is not a very long process (it can be completed in one season) and is quite simple, but for maximum efficiency with subsequent use of the structure, you need to know the main key points and take them into account when creating a project and choosing a construction site.

Seat selection

The greenhouse thermos is stationary, so the initial location is extremely important:

1. The construction should in no case be obscured.
2. Orientation of the building from east to west. In this case, maximum exposure to sunlight will be ensured.
3. The proximity of groundwater should be excluded, otherwise it will lead to excessive humidity in the greenhouse.
4. If strong gusty winds are frequent in the area where the building is located, it is necessary to provide the possibility of erecting a protective barrier at an optimal distance. Positioning it too close makes no sense. For example, if the roof rises 2.5 meters, the barrier will be functional, remote at 8-10 meters.
5. It is important to ensure accessibility to the construction site in advance in order to avoid inconvenience during work and difficulties during further visits to the greenhouse, irrigation (the location of the water supply in relation to the building should be such as to avoid unnecessary time and labor).

Sizing and shape

The size and type of the dome directly affect its heat-holding and light transmission:

• The maximum width recommended for greenhouse thermoses is 5 meters. Otherwise, the power of heating and light reflection will decrease significantly.
• The recommended height of the walls of the pit for the underground greenhouse is 2-2.5 meters. The calculation is based on data on the freezing of the soil - the depth of the pit should be twice this indicator. In this case, the soil will not only allow the accumulation of air heated by the sun and the heater, but will itself give up some heat.
• The length of the greenhouse-thermos is any, depending on the needs in the volume of the harvest.
• The design of the ground part depends on the terrain. On a flat surface, horizontal models in which the longitudinal walls are the same in height will be more convenient. Inclined greenhouses (one longitudinal wall is significantly higher than the other) are more suitable for placement on slopes. The correct angle of the roof is very important. Studies for conditions of mountainous cold terrain have shown that an indicator of 39 ° will be optimal to achieve better illumination. In this case, the sun's rays will be directed to the plants perpendicularly. This format of the structure is quite compact, but on flat terrain it is not the most preferable, since the level of natural light is significantly reduced. Possible options for the extension of such a greenhouse to the house.
• The shape of the dome can be of three types. The classic version is gable. The roof is located at an angle of 30-40 °. If the region has snowy winters, the slope should be increased. A more technological option is also possible - the equipment of the roof with a vibrator. A pitched roof is an indicator of an inclined greenhouse. Its pros and cons are discussed in the previous paragraph. An arched roof (aka a tunnel) has significant advantages in simplicity of assembly of the structure and improved illumination from all sides, but is less resistant to strong gusty winds.

When designing a thermos greenhouse, it is important to provide a vestibule. It will separate the place of direct growth of plants from the cold air of the street and serve as a place to store equipment.

Base and walls

The first stage is the excavation of the pit, based on the planned size of the structure. Soil and walls are aligned as much as possible, angles are well worked out. Then the foundation is poured (preferably for temperate and cold climates) and / or concrete blocks are laid around the perimeter. At the same stage, communications are thought out and established. A very good result is achieved when constructing floor heating in a greenhouse. The cable is laid in the soil and protected from possible mechanical damage by a mesh or poured with concrete, but this technology requires more significant costs.

The second stage is the construction of walls. This part of the structure is most often made of thermoblocks (it is possible to use another warm material or insulation from the outside, for this foam material or other material with similar functions is suitable). The blocks are mounted on a concrete base and fixed on a metal frame. To make the wall strong, they are used as formwork, then poured with concrete. The inner surface of the walls is covered with thermal insulation with reflectivity, which will save heat and evenly distribute the light penetrating from the outside. Recommended wall height above the ground - at least 50 cm.

Erection of a roof

The frame can be wooden or constructed from a metal profile. In the first case, the advantage lies in the simplicity of execution, which does not require special skills. The metal structure is much stronger and more durable, but welding work may make it necessary to invite a professional with the associated costs of paying for his services.

Shelter is made of film, glass or polycarbonate. The advantage of the film is its low cost, but the big disadvantage of this material is its short life and poor resistance to damage. Glass has good refractory properties, however, such a coating will be brittle and expensive. Polycarbonate is today recognized as the best material for the execution of the dome of the thermos greenhouse. It has good light transmittance and heat-holding ability, great strength and long life, serves as a protective shield against ultraviolet rays. The most optimal choice for a thermos greenhouse is a 6-mm honeycomb polycarbonate, and in regions with low winter temperatures - installed in two layers.

Internal arrangement

The organization of the space inside the greenhouse implies:

• The construction of beds. They should be high - bulk or placed on shelves, the width and location depends on the size of a particular building.
• Arrangement of paths - framing aisles with bounding boards and facing with brick or concrete chips, wood or other non-slip and preferably natural material. Such refinement of the space between the beds will not only protect it from the ingress of excess water during irrigation, which can make it slippery and dirty, but also give the room a more neat, well-groomed appearance.
• Filling the fertile layer on the beds.
• The supply of electricity, the installation of an irrigation system and other improvements to the interior of the greenhouse, depending on the imagination and capabilities of its owner.

Feedback from entrepreneurs and just lovers of healthy food from their garden who have already tested this technology, speak about the rationality of this choice and the achievement of very high results.