Actual topic

DIY greenhouse

In summer cottages and individual farms, typical and original designs of greenhouses can be used. However, due to the high cost of the former, typical greenhouse blocks are not widely used in private estates and are very rare in operation. For private households, you can choose hangar greenhouses with a wide span of arches or completely custom designs. Many greenhouses currently produced by industry have a steel frame made of galvanized profiles, which allows them to be operated in almost any area, in hot and cold weather. Non-ferrous metals are not forgotten - alloys based on aluminum, which are lighter in weight and have better corrosion resistance in comparison with galvanized structures, but are more expensive to manufacture and sell. There is also a small park of wooden structures, but these are mainly self-made structures or industrial greenhouses of large area (mainly Scandinavian producers) for growing vegetables in greenhouse complexes

Photo 18

The shape of the greenhouse can vary. It can stand alone or be attached to the building, or be built into the living space in the form of a winter garden. A freestanding greenhouse can have straight walls, or it can be inclined inward, sometimes of any other shape, including spherical and rounded. Moreover, for rounded forms of frames, curved glasses or their replacement from plastics can be made. These greenhouses are quite attractive and can even beautify the area on which they stand. In addition, they can compete with conventional greenhouses for a larger usable area - after all, they do not have the central path that exists with conventional greenhouses. One of the disadvantages of such structures is their increased cost due to the individuality of the project and the complexity of the frame. If you apply a little imagination, then a homemade greenhouse on New Year's Eve will become an additional decoration of the site (PHOTO 18).

Continuing the description of the structures, we will dwell in more detail on the frame made of wood. This design is the easiest to implement at the summer cottage and farm plots. This greenhouse (PHOTO 1) differs from the usual widespread designs by some inclination of the side racks inside the greenhouse - 85o and a polygonal (broken) roof. The height of the racks along the lateral surface is 2.05 m, which is due to the width of a standard sheet of cellular polycarbonate - 2.10 m (5 cm will go into the ground) - the width at the bottom of the greenhouse is 3.6 m, the width at the top of the racks is about 3.12 m, the height in the ridge is 3 m, the racks go in increments of 1 m.The material of the frame is a planed bar measuring 70 mm x 35 mm x 3000 mm, the fastening elements are corners (PHOTO 2), mounting pads, cables are not a shortage, so the real cost of such the frame in the basic version - 3.6 mx 6 mx 3 m - may not go beyond the 10 thousand rubles line. The greenhouse can be extended up to 15 m with a central vestibule and an entrance to each half of it through a separate door. The tambour can be used as an outbuilding for storing equipment and fertilizers. Ventilation is provided in the upper part of the tent (PHOTO 3). For a base length of 6 m, there are 4 vents measuring approximately 830x970 mm (0.8 m2), which are located on both sides of the ridge in a checkerboard pattern. The vents are opened using vertical bent rods made of aluminum tubes with a diameter of 15-16 mm and a length of 2 m with hooks or self-tapping screws fixed in them in the upper part with a pitch of 10 cm to fix them on the window opening (PHOTO 4).

Photo 1Photo 2Photo 3
Photo 4Photo 5
Only steel corners are used as foundations - 25x25x700 mm, since the mass of the frame is insignificant. They are driven into the ground (PHOTO 5) according to the scheme at the locations of the axes every 1 m.The process of preparing parts according to drawings is not particularly difficult (with some skill in joinery and carpentry).The main concern is the preparation of stencils for cutting corner joints at the upper and lower elements of the arches and a strictly vertical cut of the ends of all parts. These operations should be carried out with special care, maybe even using a special tool - a miter saw, so that the gaps between the elements are as small as possible - so you get the best quality of assembly of the frame parts. Photo 6Photo 7

Put the first arch, together with the assistant, along a plumb line and level, and fix it with a safety brace, and attach the subsequent ones to it using girders. Then, for the tent and side walls, fix the wind ties (PHOTO 6). They are made of a steel cable with a diameter of 3 mm and tensioning devices (PHOTO 7). This frame is easy to manufacture, but you can always come up with something that will distinguish the structure from the standard series. For growing tall vegetable hybrids, you can carry out a small modernization of an already finished greenhouse.

As for the modernization of industrial design greenhouses, and also of amateur ones, then, of course, the main recommendation is not to do anything worse than it was. After all, every unnecessary hole and cut in metal and wood can reduce the overall strength of the entire part or assembly. Therefore, first it is worth considering all possible options for alterations and only then dwell on the best in terms of safety and ease of execution. If high crops are grown in the greenhouse that require a garter on a trellis, then, first of all, it will be necessary to strengthen the ends of the greenhouse to resist the loads from the mass of plants. In a wooden structure, these elements are made of a bar of the same thickness as the entire frame - 70x35 mm, only placed on the edge to increase rigidity.

All fastening of parts to each other can be carried out using long self-tapping screws or threaded rods with washers and nuts. Additionally, you can make struts with stops that will transfer excessive load to the longitudinal elements of the frame. In arched metal greenhouses, you can use various metal elements and profiles, which can be purchased in large chain stores or in construction markets. In industrial winter greenhouses, this structural element is made of a powerful channel and a pipe, to which the trellis wire is fixed, and a tension device is attached to the other side of the greenhouse. For hobbyists, you can use galvanized threaded studs or bolts of the correct length with nuts and washers and plastic-coated steel cables to reduce corrosion. This tensioning device for the longitudinal trellis carrying the entire load from the plants is attached through the through hole of the frame (PHOTO 8, 9) outside the greenhouse, and the adjusting nuts are thus always in the access zone - outside. The modernization can also include the addition of some devices to maintain a favorable regime inside the greenhouse - a fan (PHOTO 10, 11) for air mixing, a vertical ventilation system (PHOTO 12), etc., which can be connected to a waterproof outlet inside the greenhouse (PHOTO 13).

Photo 8Photo 9Photo 13
Photo 10Photo 11Photo 12

For the device of the top covering of the greenhouse, you can mainly use different materials - polycarbonates, acrylics and other plastics, glass and polymer films of various brands. A characteristic feature of polymeric sheet materials is a lower thermal conductivity compared to glass and plain PE films. Some types of polycarbonate are able to compete in thermal insulation properties with 3 or more chamber double-glazed windows, which are much inferior in weight to polycarbonate. A square meter of polycarbonate with a thickness of 6 to 24 mm can weigh from 1.5 to 3.5 kg, which, with the same area with glass, gives a mass of glass with a thickness of 4 mm about 10 kg. And this is without the weight of the frame and the seals. But one of the disadvantages of plastics is a decrease in light transmission over time (after 10 years). But it seems that all the advantages of these materials cover this disadvantage.During this time, the cost of the coating will pay off many times over and it can be simply changed to a new one. Much less time-consuming operation than replacing the glass on the roof. By the way, glass also loses transparency from dust and other external influences, and it can be very difficult, if not impossible, to wash it, and replacing glass is already much more difficult.

The productivity of plants in greenhouses is significantly influenced by the conditions of illumination, and the relationship between productivity and illumination is directly proportional. An increase in illumination by 1% leads to the same increase in plant productivity. However, for a summer cottage greenhouse, it is hardly advisable to use additional supplementary lighting of seedlings and adult plants. Unless you have a whole greenhouse complex for the continuous cultivation of vegetables. Typically, for such greenhouses, seedlings are grown at home or bought ready for planting. If you grow your own seedlings, then you can recommend using household lamps with tubular fluorescent lamps (PHOTO 14, 15), as the most economical and cheapest. They are a metal case with two lamp mounts and lamp triggering equipment. Modern technologies have made it possible to make lamps without starters and have significantly improved the quality of light and lamp performance. They practically do not make noise and do not blink and have a fairly large resource for work. One luminaire can replace about 10 incandescent lamps in terms of power and light output, and in terms of power consumption it will not exceed 40-60 watts. The effective operation time of the luminaire is about 10,000 hours before lamp replacement.

Photo 14Photo 15

The design norms provide for orienting winter greenhouses in the central regions with skates in the east-west direction, and spring greenhouses in the north-south direction. This arrangement provides the best illumination conditions in the winter months and a moderate light regime in the spring, when overheating is possible.

When choosing a place for a greenhouse, the main criterion is considered to be good illumination and protection from winds. The latter is especially important when growing crops in winter, since heat losses are significantly increased due to wind. In case of shading by trees, the distance to the greenhouse must be at least three times its height. When obstacles are found from the southern sector, the distance to the greenhouse is 4-5 times greater than its height.

Greenhouses are built in a well-drained area with a low level of groundwater. The site is chosen with a minimum slope. This is especially important when constructing large greenhouses. Otherwise, you will have to move huge masses of land to form a flat area, or organize retaining walls and terraces. Accordingly, the foundation will have to be strengthened to resist the mass of earth that supports it.

In the spring-summer period, solar radiation penetrating into the greenhouse is excessive to create an optimal temperature regime, and in this case it is necessary to intensively ventilate the greenhouse to avoid overheating. But spring is also unstable at night temperatures, when frosts can strike, and then you will have to turn on the heating.

Heating systems for industrial and large farm greenhouses are distinguished by the type and parameter of the coolant. By the type of coolant, systems with water and air heating are distinguished. The temperature of the water for heating at the entrance to the system is + 95 ° C, at the outlet + 70 ° C. The temperature of the water for heating the soil is + 35 + 45 ° C. In all industrial greenhouses for year-round cultivation of vegetables, soil heating is additionally used using PE pipes with a diameter of 32 mm, laid at a depth of 40-50 cm from the soil level with a step of 80 cm, with a water temperature of + 35 + 45 ° C. Subsoil heating is supplemented with contour heating running along the greenhouse foundation at a depth of 40-60 cm with a pipe diameter of 57 mm to 100 mm, steel, galvanized with good waterproofing against corrosion. The water temperature in the loop heating is + 70 + 80 ° C.

When using air heating, the calculation is based on the norm of 1.5-3 kW per 1 m2 of greenhouse area. The natural ventilation system is arranged from the norm at least 15% of the total coverage area. Using forced ventilation, a calculation is made of at least 2 m3 / min per 1 m2 of hangar greenhouse area.

The heating mode in the greenhouse is directly dependent on the outside temperature. In the mode of seasonal use of the greenhouse, the operating time of the heating unit can reach 10-15 hours per day. Accordingly, the total energy consumption for heating can reach 180 kW or more per day (with a greenhouse area of ​​about 120 sq. M.).

The year-round use of the greenhouse implies a heating season from October to the end of April. In this case, the operating time of the heating unit can reach 20 hours or more per day. Electricity consumption is appropriate. All of this applies to industrial greenhouses. For amateur greenhouses, only emergency spring heating can be used and, as an outlandish variety, subsurface heating based on electric heating wires for underfloor heating. Household fan heaters (PHOTO 16, 17) for 1-2 kW can be used as heaters for summer greenhouses (for convenience, it is better with a remote control), depending on the parameters of the electrical network. In suburban settlements, the electricity limit for one house is very small, and it is rather wasteful to heat the greenhouse in this way. It is possible to replace electric heaters with others - gas and liquid fuel, of course, in compliance with fire safety measures. Now you rarely find wood stoves for heating light greenhouses - it is too troublesome to constantly maintain combustion in them. On the Internet, you can find many designs of furnaces for used engine oil, which can be obtained practically for nothing at many car services. The burning time of one portion of oil is calculated for many hours and with the correct setting of the mode, you can not go to the stove for a long time to control it.

Photo 16Photo 17

In country greenhouses, manual watering from a watering can or a hose with nozzles is usually used. A drip irrigation system can be offered. This system ensures uniform supply of nutrient solution to the plants and saves water significantly. The multiplicity of drip irrigation can reach 3-6 irrigations per day with a single flow rate through one dropper up to 150 ml. The total total consumption of nutrient solution per plant can reach up to 2.5 liters on hot days. For the entire greenhouse, the total solution consumption per day can reach 750 liters. Irrigation water must meet the requirements for drinking water: the total concentration of salts is not higher than 500-800 mg / l. The temperature of the water supplied to the plants is not higher than + 25 ° C. The drip irrigation system is controlled by a controller and does not depend on the human factor. Thus, you can water not only mature plants in the greenhouse, but also seedlings.

With year-round cultivation of vegetables, additional switching on of lamps will be required to supplement the illumination of plants in the dark period (autumn - winter - spring). The operating time of the lamps during this period can reach 10-12 hours per day. The total power of all luminaires can be up to 18 kW. The number of lamps for the entire area of ​​the greenhouse is about 45 pieces (for a greenhouse with an area of ​​120 m2).

Photo 19Photo 20
Photos 21

Microclimate regulation is reduced to regulation of air temperature, air humidity, soil temperature. For this, specialized devices and sensors are used. Each device paired with a sensor monitors the set parameters and introduces certain adjustments to the microclimate control in the greenhouse, transmitting a signal to the actuators - ventilation drives, heating valves, evaporative cooling system, etc. The controller system allows flexible control of all processes in the greenhouse.For summer cottages and small farm greenhouses, we can recommend the simplest microclimate control devices that can be purchased in electronics stores and on radio markets. To control the temperature and humidity of the air in real time, it is quite possible to use household meteorological stations (PHOTO 19.20), of which there are a lot of models with both remote sensors (PHOTO 21) and built-in ones, with high accuracy of readings and with a large measurement range, and even with a data storage device in the device memory.

$config[zx-auto] not found$config[zx-overlay] not found