Every gardener or summer resident knows that for growing vegetables any greenhouse should be equipped with a ventilation system. It is better if it is an automatic system that provides the correct and reliable temperature regime. In view of the rapid growth of inflation, making automatic ventilation of greenhouses with your own hands is a significant cost savings.
Types of greenhouse ventilation
The following types of greenhouse ventilation are available:
- natural;
- forced;
- automatic.
In natural ventilation, the quantity and degree of opening of doors, windows and transoms of the greenhouse is determined. Also, natural ventilation is provided due to the different level arrangement of window leaves in the roofs and walls of greenhouses. This is the kind of easiest airing. It is provided in small-sized premises of greenhouses. It is important to determine the time duration of ventilation depending on the ambient temperature.
Forced ventilation is carried out by forced air discharge using installed electric fans. It is important to know that equipping forced ventilation to eliminate air stagnation in large-sized greenhouse complexes, it is necessary to install fans for air recovery.
The automatic ventilation system provides for the opening and closing of windows, doors and transoms in automatic mode.
Appointment of automatic ventilation
During the use of solid fuel or gas heating, a large amount of combustion waste accumulates in the greenhouse, as well as carbon dioxide and carbon monoxide, which adversely affects plants: their development, growth, ripening. In this case, the automatic ventilation of the greenhouse, made by hand, is established, and making it possible to maintain the desired microclimate.
Automatic ventilation systems
Raising or lowering the temperature in the room is not a sufficient condition for the process of plant cultivation. The importance is the support of the desired temperature and humidity conditions. Indeed, with increasing air temperature, humidity in the greenhouse rises, contributing to the propagation of fungi. Therefore, to maintain the temperature within 20-30 degrees, various methods or systems for ventilating greenhouses are used.
There are three main ventilation systems for greenhouses:
- electric;
- bimetallic;
- hydraulic.
Greenhouse electrical ventilation system
Making and installing electric automatic ventilation of greenhouses with your own hands is quite simple. It consists of a thermal relay and fan, forming a closed electrical circuit.
The principle of operation is simple: when the temperature in the greenhouse is higher than the permissible value, then the thermal relay starts the air cooling fan. The disadvantage of such a ventilation system is a power outage in the hot season. The way out of this situation is to work from a battery system or install a solar battery.
A kind of electrical ventilation
A type of electrical ventilation of rooms is forced electric ventilation. It is installed in large-sized greenhouses or in complexes consisting of a number of greenhouses: if necessary, create different climatic conditions in different rooms. The whole structure is fans and temperature regulators, closed in the system and working independently, creating a different microclimate. At the same time, the desired number of fans working to create the desired temperature is connected to one thermostat.
Forced electrical ventilation is exhaust and supply.
With the exhaust type of ventilation of greenhouses, ventilation is carried out by the outflow of warm air.
The supply type is the ventilation with cold air inside.
The advantages of an electric ventilation system:
- high power;
- accurate ventilation time according to the setting of thermal sensors;
- high adaptability of the system.
Bimetal ventilation method
The simplest device is a bimetallic automatic ventilation of greenhouses, installed manually. And easily, and without other additional devices.
This design consists of two metal special plates having a different strain coefficient when exposed to external heat. The plate, increasing in size and bending, opens the window when heated. And when the temperature drops - it closes the window, decreasing and bending to its original position.
Advantages of the bimetallic design:
- full autonomy in work;
- reliability;
- simplicity.
The main disadvantage of this method is the inability to lift heavy structures due to low power.
Hydraulic ventilation system
Many summer residents are wondering: how to make automatic ventilation of the greenhouse with your own hands the most effective? The answer is obvious. This is a hydraulic ventilation system. It is installed on the windows, transoms and doors of greenhouses.
Consider the principle of opening and closing transoms.
Structurally, these are hydraulic levers located on the inside and outside of the greenhouse with installed temperature sensors on transoms. When the indoor hydraulic cylinder is heated with air, this heated air moves toward the outer cylinder. Moreover, in view of the imbalance of the structure (overweight), the transom is opened.
The main advantage of such a system is the durability and the ability to lift a lot of weight. The disadvantage is that it cannot be applied on the side windows. In addition, she slowly responds to weather changes.
Modifications of hydraulic systems for ventilation of greenhouses
You can make automatic ventilation of greenhouses with your own hands, which will be based on a thermal cylinder and bellows. It is a sealed system filled with acetone. The principle of operation is the same.
There are industrial automatic windows, consisting of the window and the oil cylinder with a piston and pusher. Oil expanding during heating causes the piston to move, and accordingly the pusher that opens the window. The reverse order of the process occurs when the temperature drops.
Automatic ventilator
There is another device - an automatic thermal actuator or ventilator.
It consists of a metal cylinder filled with a special fluid and a working rod. A fluid heated to a temperature of 23 degrees pushes the rod, which opens the window. This is how the greenhouse is automatically aired. Do-it-yourself thermal actuator with the help of complete fasteners is installed on the window of the greenhouse.
There are various thermal drives. With their help, it is easy to establish automatic ventilation of the greenhouse. With their own hands, craftsmen make working ventilation mechanisms from a shock absorber, a cylinder of a computer table or a hydraulic cylinder of a car.
Cupping system
The most original hydraulic method of ventilation is the can method, which is based on conventional household seaming cans.
For this, three-liter and 800-gram cans are used.
Eight hundred grams of water poured into a three-liter jar are rolled up with an ordinary sealing lid. A copper or brass tube is inserted into the lid, not reaching the bottom of the can about three millimeters, which is tightly sealed. A hole for a flexible tube from a dropper is made in a polyethylene lid worn on a smaller jar, and is also sealed. This will be one of the types of pneumatic siphon. The design is placed inside the greenhouse, adapted to the frame of the counterweight beam.
Such a system works quite simply: when the temperature rises, warm air displaces water from a larger tank to a smaller one. Due to the increase in the weight of the can, the window is opened. If the temperature drops, the water goes into a large jar, and the transom closes with a counterweight. This is how a self-made bottle automatic ventilation system made and installed.
Disadvantages of the system:
- the device works only in the horizontal axis;
- periodic refilling of water in a large tank is required.
Well, to the question of what it is possible to make automatic airing of the greenhouse with your own hands, which would not be costly and time-consuming, you can offer a variant of the bottle method, where instead of glass breaking cans, polyethylene bottles are installed. But this, so to speak, is a lightweight system. But how to make it more rigid? You can do the automatic ventilation of the greenhouse with your own hands from the Zhiguli shock absorber, or rather, from the gas shock absorber from the Zhiguli.
Thermal actuator from gas shock absorber
It is no secret that often the automatic ventilation of the greenhouse with their own hands is made literally from those materials that fall into the arm.
To make a device for automatically ventilating greenhouses with your own hands - a thermal drive from a gas shock absorber - you need to take two pieces of a metal pipe with a diameter of three quarters of an inch and, cutting the threads at the ends of both pieces, connect them using a tee. End ends must be plugged with standard plumbing plugs. In the gas shock absorber from the Niva car, the lower pin is cut off, a hole is drilled and an M10 thread is cut . Having drilled through a bolt from a brake hose and a cap with a drill by 10, we twist a bolt with a lock-nut in a cap.
The remaining free part of the bolt is screwed into the thread in the shock absorber; all connections are sealed with gaskets. The plug with internal thread is connected to the tee by means of a drive with a lock nut. Now you need to unscrew the plug from the end of the pipe and add oil. To do this, the rod moves into the lower position, and in the vertical position of the pipe, the air leaves the shock absorber. It remains only to tighten the plug and fix the structure in the greenhouse.
Thus, the necessary condition for the cultivation of vegetable or berry crops, seedlings or flowers is the automatic ventilation of the greenhouse, made by hand and giving a significant increase to the family budget.