Thermal drive for greenhouses: features and benefits of operation

Life in the style of organic and eco forces modern craftsmen to resort to the most comfortable arrangement of their land plots in order to develop more qualitative products. Often, everything that is planted on the plot is used for itself, rarely among modern farmers with a small garden, they organize the cultivation of vegetables, fruits and berries on an industrial scale. However, simple summer residents and gardeners have much to learn from professional farmers. For example, the automation of various processes in greenhouses.

The need for ventilation

All residents of apartment buildings are aware that you can get fresh vegetables in the winter or early spring only in the store.But those who have at their disposal at least a small piece of land, can personally arrange a vegetable feast during the cold weather and the poor harvest. For these purposes, greenhouses are often equipped in kitchen gardens. Such household building can be made of various materials: from dense industrial film to heavy glass. The most popular today greenhouses made of polycarbonate.

The main principle of the greenhouse is to create the most comfortable conditions for growing crops.

Several factors contribute to this.

  • Maintain temperature. For the full functioning of the greenhouse inside should be at least 22-24 degrees Celsius.
  • Optimum air humidity. This parameter is developed for each individual plant. But there is also a certain rate, which ranges from 88% to 96%.
  • Ventilation. The last item is a combination of the previous two.

In order to normalize the necessary indicators of temperature and humidity in the greenhouse, it is necessary to arrange air baths for the plants. Of course, you can do it yourself.In the morning - opening the doors or windows, and closing them in the evening. So they did before. Today, agricultural technological progress has allowed inventing devices for automatic opening and closing of windows in greenhouses.

It should be understood that the standard methods of device drafts for plants are unacceptable. Too sharp temperature or humidity level can cause deterioration of the culture and its death. If in film greenhouses there is a variant of self-ventilation (due to the lack of tightness of such structures), then glass and polycarbonate buildings very much need automatic ventilation.

In addition to monitoring these indicators, there is also a risk of developing pathogenic bacteria and microorganisms., negatively affecting the growth of fruits and vegetables. Many insects also prefer warm and humid places for their dislocation. Periodic air baths in greenhouses will bring them discomfort. Thus, no one encroaches on your future harvest.

In order not to worry and not to run every half hour or hour to the greenhouse, checking all indicators, experts in the field of agriculture advise to purchase and install thermal actuators. What is it and how it works, we will understand further.

Features and benefits of application

In fact, the thermal actuator is an automatic closer, which is driven by increasing the temperature in the room. Relatively speaking, when the plants get too hot, the window opens.

This auto ventilator has a number of nice benefits.

  • There is no need for constant monitoring of the temperature in the greenhouse.
  • For his work there is no need to conduct electricity.
  • You can buy a thermal drive in many gardening stores and departments of building hypermarkets at an affordable price. You can also make it yourself from practically available tools.

Before proceeding to the choice of one or another automation for ventilation of the greenhouse, pay attention to the features of installation and use of this tool.

The first and basic rule is to pay attention to the fact that the effort to open and close windows and doors should not exceed 5 kg.

The second nuance is the selection of the required place where the ventilator will be located. Since it consists of two parts and has two fasteners, one of them must be attached to the wall of the greenhouse, and the second to the window or door.In this case, you need to check how convenient and easy it will be to mount one of the fixings on the wall of the structure.

The third feature of greenhouse thermal actuators is that the internal cavity of the working cylinder is always filled with liquid. This circumstance and controls the opening and closing of windows and doors. Therefore, manufacturers do not advise to disassemble the design of the device, so as not to harm. Full functioning is possible only if there is a certain amount of liquid.

Pleasant is the fact that self-opening windows and doors can be applied to any design: from standard film to durable polycarbonate structures. Even in a dome-type greenhouse, an automatic thermal drive would be appropriate.

Characteristics and working principle

Regardless of what type of thermal drive is used, its main function is auto-ventilation in case the temperature exceeds the maximum allowable threshold. When this indicator decreases and becomes optimal, the drive is activated when the window or door is closed.

There are only two main working devices in the thermal drive: temperature sensor and the mechanism that drives it. The design and location of these components can be very diverse. Also, this device can be equipped with closers and special locks, which ensures tight closure.

Machines for doors and vents in the greenhouse are usually divided into types according to the mechanism of action.

  • Volatile. This is an electric drive that moves with the help of a motor. To turn it on, the device has a special controller that responds to the readings of the thermal sensor. A huge advantage of this type of thermal drive is the ability to program it according to your individual parameters. And the biggest drawback is its volatility. An interruption of electricity is possible when you do not expect it at all, for example, at night. First, the centralized power outage may cause a malfunction in the program of this type of thermal drive, and secondly, the plants may undergo freezing (if the autofocus remains open after the light goes off) or overheat (if the ventilation did not happen at the scheduled time).
  • Bimetallic. Arranged in such a way that the plates of different metals, interconnected in a certain configuration, react to heating in different ways: one increases in size, the other decreases. This bias makes it easy to open the window for ventilation in the greenhouse. The same action takes place in the reverse order. You can rejoice in this system by the simplicity and autonomy of the mechanism. The disorder can provide the fact of insufficient power to open a window or door.
  • Pneumatic. Today it is the most common piston system of thermal actuators. They act on the basis of supplying heated air to the actuator piston. This happens as follows: a sealed container is heated and air from it (increased, expanded) is transmitted through the tube to the piston. The latter brings the whole mechanism into action. The only drawback of such a system is the increased complexity of its independent execution. But some craftsmen were able to think of this. Otherwise, there are practically no complaints about pneumatic thermal actuators.
  • Hydraulic. The most simple and often used in private garden farms. The basis is taken two communicating vessel. Fluid from one to the other is transmitted by varying the air pressure during heating and cooling. The advantage of the system lies in high power, full energy autonomy and ease of self-assembly from improvised means.

Very good reviews today receive domestic thermal drives of various kinds. Install at least one of them is not difficult even for a person who does not understand anything about it. And the pleasant cost of systems for automatic airing of greenhouse structures pleases both the eye and the budget owners' wallet.

If you decide to make a thermal drive yourself, use the step by step instructions for this process. It is necessary to make not only efforts, but also diligence and maximum attention to all the details in order to achieve the desired result.

How and what to do yourself: options

Plus, creating a thermal drive with your own hands is the ability to use scrap materials. It is enough to prepare all the necessary details for this.

An office chair is a very convenient and simple way to make a car thermometer. How often, while working at a computer, did you raise, then lower the seat to the required level? It was possible thanks to gas lift. Sometimes it is also called lifting cylinder.

To make a thermal drive for the greenhouse with your own hands out of this part of the office chair, perform such manipulations with it.

  • The cylinder consists of two elements: plastic and steel rods. The first stage of work is to get rid of the plastic body, leaving only the second, more durable.
  • Putting the spare part from the main piece of office furniture to the side, pick up a metal rod with a diameter of 8 mm. Fix the part in a vice so that a piece of about 6 cm is left on top.
  • Tighten the prepared cylinder on this rod and push as hard as possible so that all the air escapes from the latter.
  • Cut a part of the cylinder with a tapered end and squeeze a steel rod through the hole. Try not to damage the smooth surface and the rubber band.
  • At the end of the stem it is necessary to make a thread that will fit under the M8 nut.
  • Now the extruded sleeve can be put back in place, being careful and protecting the aluminum piston.
  • The steel rod is inserted into the inner sleeve and pulled out from the back of the cylinder.
  • So that the piston does not move, it does not fall into the cylinder during operation, screw the M8 nut onto the prepared thread.
  • Insert the aluminum piston into the valve seat. Weld the steel tube to the cut end of the cylinder.
  • Attach the resulting mechanism to the window control unit.
  • Release all the air from the system and fill it with oil (can be machine).

Thermal for the greenhouse of the parts of the office chair is ready for use. It will only check the device in practice and use it.

Of course, the manufacture of such structures with his own hand is a very laborious process. But the result of painstaking work and care will exceed all expectations.

Another available tool for creating an automatic greenhouse ventilation system is a conventional car shock absorber. The main active ingredient here will also be motor oil, which reacts very subtly to minor temperature drops,what drives the whole mechanism.

The thermal drive for the greenhouse from the shock absorber is performed in a specific sequence.

  • Prepare the necessary materials: gas spring shock absorber car, two cranes, metal tube.
  • Near the vent, the opening and closing of which is planned to automate, install the shock absorber rod.
  • The third step is to prepare the pipe for engine oil. Attach a valve to one end of the pipe for the input of engine fluid, to the other - the same design, but to drain it and change the pressure in the system.
  • Trim the bottom of the gas spring and connect it to the oil tube.

Thermal drive from the parts of the automotive shock absorber is ready for operation. Watch the oil level in the tube to avoid incorrect operation of the system.

After talking with professionals, digging in their unnecessary parts in the garage or shed, you will find a large number of parts needed to create your own design of thermal drives. If the installation of finished products is carried out as quickly and simply as possible, then even making a hand-made mechanism with a door closer or lock will not be difficult for you.

After putting the system into action, it is necessary to take care of it so that it also justifies its peculiarity in terms of the durability of the mechanism.

Tips for use and care

Thermal drives for greenhouses are very unpretentious in the care. They need periodic lubrication of the moving elements, control of the fluid level, changes in the physical parameters of which drives automatic systems.

Also, if you do not plan to use the greenhouse in the winter season, experts recommend removing thermal actuators from windows and doors in order to prolong their service life.


Today, the market has a wide range of domestic thermal drives for greenhouses. Feedback about them is ambiguous. Some buyers complain about the high cost of the automatic discoverer of a plain construction (about 2000 rubles apiece).

Among the advantages, consumers emit, of course, the automation of the process of ventilation of the greenhouse structure, but at the same time they rejoice at the possibility of manually opening / closing the greenhouse if necessary.

Reviews on the installation of thermal actuators are present in small quantities.For example, buyers focus on the fact that the installation of most of them on the wall of the greenhouse is necessary. That is, the standard polycarbonate “wall” is not able to withstand one of the parts of the thermal actuator. To do this, it must be strengthened, for example, with a sheet of plywood, a board or a galvanized profile.

The rest of the modern farmers are pleased with this purchase and happily share their impressions of the mechanism that automates their efforts to grow high-quality agricultural plants.

How to make a thermal drive for the greenhouse with your own hands, see the video below.

Information provided for reference purposes. For construction issues, always consult a specialist.

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