Thermal drives for greenhouses: features and methods of use
Ventilation for a greenhouse is a system of measures that is designed to maintain temperature, humidity, and also to replenish the volume of carbon dioxide. Due to this, the cultivation of crops is successful.
The ventilation process is carried out by exchanging the air that is inside the greenhouse with the air that is concentrated inside.
The need for ventilation: the reasons
To grow a large number of quality products, gardeners and gardeners should provide the most comfortable conditions for their land plots. The work of the greenhouse is to maintain optimal conditions for the growth and development of vegetables. To do this, it performs the following functions:
- maintains the temperature, which must be at least twenty-two degrees of heat;
- maintains optimum air humidity, which is unique for each type of plant;
- provides airing.
In order to carry out the process of normalizing such necessary indicators as temperature and humidity, plants must “take air baths”.
A few years ago, airing was carried out by opening windows and doors. But today there are devices for automatic opening and closing of windows in greenhouses. The standard method of airing is not quite suitable for normal plant life. Since a draft is a sharp drop in temperature and humidity in the room, which can have a detrimental effect on culture.
In addition to automating, it controls the necessary climatic indicators, it can prevent harmful bacteria and fungi from entering the greenhouse. That is why to save your personal time and normal microclimate in hotbeds it is recommended to install thermal actuators, they will provide high-quality ventilation, because every farmer knows that the presence of fresh air is the key to rapid plant growth.
Features and benefits of application
The heat drive is an automatic closer that starts its work when the air temperature in the greenhouse rises and the window opens. In other words, its principle of operation is based on the fact that the window opens when the temperature for crops is too high. The autovent has such positive characteristics as:
- it is not necessary to constantly monitor the air temperature in the greenhouse;
- to function, the ventilator does not need to be connected to the mains;
- self-opening automation for windows can be purchased at any building or gardening shop, as well as make your own hands.
Before buying a thermal drive, you should not overlook the peculiarity of the installation and use of the ventilator. It is important to know that the effort during the opening and closing of the window opening should not exceed five kilograms. The thermal drive consists of two elements, the first of which is attached to the wall of the greenhouse, and the second - to the window or door. The peculiarities of the ventilator include the fact that the cavity inside it is filled with liquid. This moment is crucial for the need to open or close the window. That is why it is not necessary to disassemble the autovent on separate elements, as this may harm its design. The device functions fully only if it has the necessary amount of liquid.
Important! The advantage of this device is that it can be used both in a greenhouse made of polycarbonate and in a greenhouse “dome” of a different material and shape.
Characteristics and working principle
Whatever type of thermal actuator is used, its main task is to ventilate the room with high quality as the maximum permissible temperature threshold increases. In case of reduction of this indicator to the optimum rate, the controller closes the door and window. A temperature drive is a device consisting of two parts, such as:
- temperature sensor;
- the mechanism that drives this device.
These components can be located and designed differently.
The autofocus can also be supplemented with a door closer and a lock, which are responsible for the tightness of closing the holes during self-ventilation.
There are several types of automatic airing for greenhouses, which differ in the mechanism of work.
- Volatile. This drive drives the motor. The function of turning on the device is performed by the controller, it is able to quickly respond to the reading of the temperature sensor. The advantages of this thermal drive include programming of its parameters at the discretion of the user. As a disadvantage, it is possible to distinguish its dependence on electricity, with which there are often failures.
- Bimetallic. His device includes several plates of metal, which are interconnected. Each component differs in response to a change in air temperature. The size of the first at the same time increase, and the second, on the contrary, decrease. This feature makes it possible to easily open the vent for airing and in reverse order. This system is simple and autonomous, but at the same time it has the disadvantage of low power for opening and closing.
- Pneumatic. In our time, this species is considered the most common. The basis of his work is the supply of heated air to the piston system. From a sealed heated vessel, air is sent to a piston drive, which is mounted to actuate the entire mechanism. The disadvantages of the device include only the fact that it is quite difficult to do it yourself.
- Hydraulic. It has a simple construction and is therefore often used in recent years. Its basis is two communicating vessels. The fluid from the first to the second is transferred when the air pressure changes, when it is heated and cooled. The positive characteristics of the device include its good power, non-volatility and ease of assembly. Deficiencies not seen.
Thermal actuators have the following positive characteristics:
- reliability - thanks to the quality materials from which the device is made, auto-openers withstand enormous pressure; the products are quite durable, as well as resistant to strong wind and an accidental attempt to close the door manually;
- long service life;
- no need for adjustment;
- universality of use;
- the ability to install without having professional skills.
Many people think that the independent production of thermal drive is an impossible task. But this is not quite the right opinion, since in practice everything looks much simpler than it seemed. To do the work you need to spend time, effort, and apply the appropriate knowledge.
Do-it-yourself self-winding can be made in several ways.
From the cylinder from the computer chair
Using the objects at hand to create something useful is interesting, practical, and effective. The main rules when working are consistency and clarity of execution. For the manufacture of devices for ventilation it is necessary to take a cylinder from a chair for a computer, on one side of it there is a rod made of steel, on the other - from plastic. The process includes the following steps:
- it is necessary to pull the rod out of plastic;
- the cylinder must be relieved of pressure from the inside by putting a metal pin on it;
- the cylinder is cut by the grinder;
- it is necessary to carefully remove the stem from steel without damaging it;
- M8 thread is put on the rod for safety, and the part is clamped in a vice;
- from the internal parts of the cylinder will only need to use a sleeve that is put in place and the piston of aluminum, from which rubberized rings are taken;
- each element should be cleaned by washing in gasoline;
- Carefully insert the stem into the sleeve, the end of which must be outside;
- it is necessary to tighten the nut on the existing thread, which is designed to hold the stem;
- further inserted rod of aluminum;
- an elongated nut is put on the rod thread;
- plug must be inserted and connected to the control levers;
- system should be filled with engine oil.
Thus, the thermal actuator will be ready to use and perform its immediate tasks.
From automobile hydraulic cylinder
Installation of this device should be done with extreme caution. performing the following actions:
- there is a gas in the cylinder, it must be released by drilling holes;
- a hose is attached to the hydraulic cylinder - for this, a thread is cut and the hose is attached with a bolt that has an M6 stud;
- You need to prepare the receiver in advance for a process that is best ordered from specialists;
- after squeezing the air out of the system, it is necessary to refill it completely;
- It is worth checking how well the device is sealed.
Working with gases is quite dangerous, so do not forget about the elementary safety rules.
With consistent and proper implementation of all stages of creating auto-ventilation, this system will work efficiently.
From car shock absorber
This option is not an easy way to make autoscan from improvised means. In this situation, as in the previous one, the main active element is motor oil. It is this substance capable of a subtle reaction to any temperature difference, contributing to the beginning of the functioning of the system. The execution of the thermal drive for the greenhouse from the shock absorber has the following sequence:
- preparation of materials - a gas spring from a car shock absorber, two taps and a metal tube;
- about the window, which will carry out ventilation, you need to install the shock absorber rod;
- it is necessary to prepare a tube for the oil - a tap is connected to the first edge of the pipe, which regulates the flow of engine oil, to the second edge - a similar design that will perform the function of draining;
- The bottom of the gas spring must be cut off and then connected to the tube with oil.
After completing all the above steps, you can create a thermal drive. The main thing is not to forget to check the status of the oil in the system. Tips of professionals, their own ingenuity and perseverance will be excellent assistants in creating a thermal actuator with their own hands, using unnecessary tools at hand.
Installation of the device with a closer and without it also does not become a problem, because the design of this type of ventilation is rather primitive.
Tips for use and care
Thermal drive for greenhouses does not differ whimsical care. Obligatory to perform is the lubrication of the elements of the device that move. And also you should not forget that the level of the liquid must be constantly monitored, as well as the physical indicators changed, which are set in motion by the automatic system. Provided that the greenhouse will not be used during the winter period, it is recommended to remove the thermal actuator from the window or door. Such an event can significantly increase its service life. Important points in the maintenance of the auto ventilator are the following:
- annual oil lubrication;
- It is forbidden to disassemble the device or change their design, as this may cause the thermal actuator to become unusable;
- when working, the fan should not interfere with anything;
- Do not fix the device when it is closed;
- doors and vents should not have handles and latches, which can interfere with the effective operation of the system;
- Do not overdo it when opening the autovent door.
It is worth carrying out installation of the thermal actuator correctly and with all responsibility. The best place to install it will be the ventilation frame - this is exactly the place where the system will work well. Due to the presence of thermal drive work on greenhouses will become much easier. The main thing is to take the device carefully and do not forget to care for it.
There are many good reviews from domestic thermal drives, which have different types. They are characterized by ease of installation, so the installer will be built under the force of everyone who wishes. And also users are pleasantly pleased with the affordable price of devices for airing. A small number of not entirely positive responses associated with the installation of the device. Users say that before installing the auto ventilator, it is necessary to organize a platform for its attachment, since standard polycarbonate walls cannot fully withstand the structures. A plywood, galvanized sheet or profile will help solve the problem.
According to summer residents, it is better to install the autovent on the side located on the opposite end of the opening that opens. People who made the thermal actuator on their own note that their devices have a slightly delayed reaction to a change in temperature. Everything else completely suits both farmers and gardeners-amateurs.
Installing a thermal drive is a great way to automate labor, which will help plants grow, develop and temper well.
From the foregoing, it can be concluded that auto-ventilation for the greenhouse is a necessary thing. The heat drive is a great helper who will create comfort and coziness in greenhouse cultures, without wasting your time. The cost of the discoverer is available and fully pays off. In addition, such a thing can be easily assembled with your own hands. This is ideal for those people who have decided to try themselves in plant breeding, but do not have the ability to constantly monitor vital signs for crops in greenhouses.
How to make a thermal actuator with your own hands, see the next video.