Automatic opening of the greenhouse: do-it-yourself thermal drive

Thermal drive for a greenhouse - Everything you need to know

Thermal drive disassembled

1. If you keep a greenhouse or greenhouse, then you know how important it is to ensure timely and properly organized ventilation. During this time, the incoming fresh air provides: An acceptable level of humidity - harmful bacteria, as well as all kinds of parasites, will not be able to reproduce in such conditions
2. Good conditions for photosynthesis
3. Suitable temperature - plants may freeze or dry out if the heifer is not exposed/exposed too much
4. Microclimate - the better it is, the higher the return from the greenhouse in the form of a healthy harvest
5. Healthy plant immunity
6. Natural pollination - insects performing this task also need to somehow penetrate the greenhouse/greenhouse

In addition, you are unlikely to be able to cope with this problem on your own, as they say “by hand”. After all, then you would literally have to live in a greenhouse and unlock/close doors and windows strictly according to the schedule.

Installed thermal drive

Ventilation is indeed a very important aspect in gardening. It can become either your ally or your enemy - it all depends on how you approach its technical organization. The most optimal solution in this case would be automatic ventilation of the greenhouse. And an automatic thermal drive for ventilation will come in handy.

Why do you need to ventilate a greenhouse?

In greenhouses, it is necessary to maintain a temperature regime that is favorable for the planted plants. The greenhouse effect creates suitable conditions for the growth and development of heat-loving seedlings, but if there is no circulation of fresh air, the plants in the greenhouse begin to get sick. Without ventilation, the seedlings' photosynthesis process is disrupted and they do not receive enough vital elements. The air temperature rises and the plant dies. Therefore, ventilation of greenhouses is necessary and should be carried out regularly.

Gardeners often face the problem of opening windows or doors in a timely manner. There are situations when a person simply forgot that the greenhouse is closed or open. When he remembers this, the plants have already suffered and require immediate resuscitation. To prevent such cases, a thermal drive was invented that opens the windows or doors of the greenhouse automatically.

How does a thermal drive work?

The operation of the device depends on the air temperature. On a clear day, when the sun heats the greenhouse, the liquid in the thermal drive parts heats up, parts of the device expand and push the door or window. It opens and air flows to the plants. Closer to sunset, the air temperature outside and, accordingly, in the greenhouse decreases. The thermal drive cools down and contracts, the vents close completely.

Comment! To ensure that the thermal drive located under the ceiling does not heat up from the sun's rays, but only from the air temperature, it is recommended to shade it.

Automatic ventilation machine Thermodrive - DV

The operating principle of the DV thermal drive device for automatically opening doors and vents in greenhouses is very simple. Full opening of the sash occurs at an air temperature of +30 degrees. When the temperature drops, the auto-opener begins to close the greenhouse flap and closes it completely at a temperature of +21 degrees. The thermal drive DV sensitively reacts to changes in temperature during the day, either opening or closing the greenhouse and, thereby, guaranteeing automatic ventilation of the greenhouse.

Types of thermal drives for greenhouses

Thermal actuators are divided into types, the principle of operation of which differs from each other. Each of them is designed for different types of vents and provides different ventilation methods. If the sash opens upward, some thermal actuators may be unusable. Each type of device has its own advantages and disadvantages that you need to know about.

Electrical

It is a ventilation system with blade elements that are activated using temperature sensors.

The temperature at which the vents open and close can be adjusted manually. Standard mode: opening from + 23 °C, closing from + 17 °C.

Another option for an electric drive for greenhouses is a mechanism similar to a device operating on a hydraulic principle. The pin is driven mechanically, following a signal from a temperature sensor. You can make such a thermal drive yourself.

Pneumatic

The thermal actuator consists of a cylinder with compressed air and a rod, which, when the air is heated, moves out of the structure and lifts or opens the doors of the greenhouse. The rod drops inward when the temperature begins to drop.

Comment! If the window is located on the wall and opens to the side, then a spring or a closer is needed to close it.

Hydraulic

Such devices work similarly to the previous ones, the only difference is that instead of compressed air, there is liquid in the cylinder. Basically it is oil, the particles of which expand when heated and push out the rod. The vent closes slowly when the temperature drops. Ventilation is carried out by a smooth change of air, thanks to the inertia of the thermal drive.

Bimetallic

The thermal actuator consists of metal plates that have the ability to expand when exposed to warm air. When the air in the greenhouse heats up, one of the plates bends and pushes the window.

Gardeners using bimetal as a thermal drive for greenhouses noted that the plates heat up slowly. Therefore, this type of device is not popular.

What is a thermal drive, advantages, disadvantages

A thermal actuator is a device that allows you to automatically open and close ventilation holes in order to regulate the microclimate.

The operating principle of a thermal drive is based on the use of a liquid in a closed cylinder that can change its volume depending on temperature. A change in volume activates the mechanism. Cyclohexanol is commonly used.

The advantages of thermal drives include:

• the ability to open/close/open a wide range of devices: vents, doors, windows, frames;
• reliability;
• ease of operation and no need to manufacture
• additional settings;
• ease of installation.

Despite the obvious advantages, thermal drives are not without disadvantages:

• fastening to glass windows requires devices of greater power due to their relatively high mass;
• When installing the device, it is necessary to take into account the size of the greenhouse.

Practice shows that the best results can be achieved when installing thermal actuators in greenhouses made of cellular polycarbonate.

Homemade thermal drive for a greenhouse

Ready-made devices for automatically opening greenhouses are expensive; in order to save money, you can make a thermal drive yourself. First, you need to decide how long the service life of the homemade device is expected to last. There are options that will last only one season, but you can make a thermal drive that will last several years. For those who are familiar with electricity, you can make an electric drive for the greenhouse door, but there are simpler options.

From an inflatable ball and cylinders

This version of a homemade thermal drive can last 1-2 seasons. To make it you will need:

• wooden box;
• 2 cylinders;
• rubber hose;
• board;
• the ball or camera from under it.

The cylinders are fastened together using tape or wire. A rubber hose is attached to them. The other end of the hose is attached to the inflatable valve of the ball. The ball is placed in a box so that when it expands it pushes out the wooden lid. The box is placed under the window, and a board is placed on the lid so that when it is moved, the board opens the window. The cylinders are suspended from the ceiling.

As the temperature rises, the cylinders heat up and supply warm air through the hose into the ball. He inflates and pushes off the lid of the box. The board fixed at the top puts pressure on the window frame, opening it. When the air temperature decreases, the process occurs in the opposite direction.

Comment! The hose must be of such length that air can pass through unhindered. You can't leave any extra length.

From a plastic bottle

The cheapest and fastest way to build a thermal drive for a greenhouse with your own hands. This option will only last 1 season.

Materials:

• 2 bottles, one of which is 5 l and the other is 1 l;
• dark tint film:
• board;
• pipes 2 pcs.;
• thin tube over 100 cm long.

The bottles are washed and dried. A large container is wrapped in dark film and a hole is drilled in it. Insert the pipe and connect it to one end of the tube. The joint is made airtight by coating the joint with a special paste. A 5-liter bottle is fixed under the ceiling. The second end of the tube is connected to the neck of a liter bottle, and a board is attached on top.

A liter bottle crumpled under the board under the influence of air from the top 5-liter container will straighten and lift the board. That, in turn, will have an impact on the window frame, lifting it.

Comment! This design is not suitable for opening massive, heavy doors.

From an office chair cylinder

Office chairs have a mechanism that adjusts the height of the seat, it is called a gas lift. This part is suitable for constructing a thermal drive.

Additional tools:

• machine oil;
• a piece of metal pipe of suitable diameter;
• welding machine;
• Bulgarian saw;
• vice.

The end of the plastic rod is clamped in a vice and pulled out until the pin on the valve becomes visible. Bleed air from the main cylinder. Its axis is fixed in a vice and pressed from above. The upper part of the cylinder is carefully trimmed with a grinder. There is a risk of damaging the seal and the surface of the part itself.

The rod is carefully removed from the sleeve, monitoring the condition of the seal. It must not be damaged. To prevent the rod from falling back into the cylinder, a nut is screwed onto it. Then the aluminum piston is inserted and welded. The final step is to screw the nut onto the thread, and then fix the rod on the window frame. Oil is poured into the ventilator and it is ready for use. The operating principle will be hydraulic.

From an automobile hydraulic cylinder

This thermal drive option will last for several years. To make such a device for ventilating greenhouses, it will take about 1 hour.

First, the gas is squeezed out of the shock absorber, and then a small hole is drilled and threaded. The brake hose is fixed in the hole. The receiver for the thermal drive is made independently or ordered from turners. Oil is poured into the shock absorber, and the rod is completely immersed inside. The device is ready, all that remains is to make sure that it is completely sealed and make sure that the oil does not drip. The structure is attached with a rod to the window, and the other end is fixed to the support.

Comment! The device will work better if it is placed at the top of the greenhouse.

From a car shock absorber

What is required to create such a thermal drive:

• shock absorber piston or spring;
• taps 2 pcs.;
• cylindrical container for oil (metal pipe);
• machine oil.

Taps are welded at both ends of the pipe. One of them will serve as a pressure regulator, and the other as a hole for filling with oil. The bottom of the spring is cut off using a grinder. Then it is welded to the pipe. The final step is to check the device for leaks.

Comment! This type of thermal drive is suitable for large greenhouses and heavy window frames.

The need and importance of ventilation

A summer resident who has installed a greenhouse on his plot is faced with many tasks, the resolution of which is necessary to obtain a rich harvest. But often he has to solve real puzzles. It is necessary to simultaneously maintain heat, as well as protect the plants from bad weather and establish a flow of fresh air to get rid of excess moisture.

We are talking about organizing high-quality ventilation. For those new to gardening, its role is not entirely clear. Meanwhile, without it you cannot grow a good harvest. There is even a threat of killing it in the bud due to the creation of a harmful microclimate in the greenhouse.

Reasons for ventilating a greenhouse:

• Where there is no access to fresh air, a high humidity regime is established. This is fraught with the appearance of pathogenic microorganisms;
• Not only bacteria like a stuffy environment. Various pests happily reproduce in it;
• The process of photosynthesis requires a fresh atmosphere. In a waterlogged environment with a high carbon dioxide content, it is impossible;
• Plants love warmth, not heat. At constantly high temperatures, even with an abundance of water, they burn and die;
• Regular ventilation strengthens the immunity of plants and hardens them;
• The same can be said about seedlings standing in a greenhouse. Systematic air baths prepare it for an independent struggle for life on the ground;
• Without ventilation, the pollination process is impossible.

Heat above +40°C and scorching rays of the sun harm plants. In this case, excess heat is not beneficial, but can destroy the fruits of the summer resident’s labors. In a closed room, the temperature rises very quickly. If ventilation is organized correctly, this will ensure equalization of the microclimate. The condition of the plants will return to normal, which will ensure a good harvest.

When talking about organizing the microclimate, you need to remember one rule: what suits humans does not suit plants. Therefore, a primitively open window will not help. It is necessary to consider an effective ventilation system, especially for polycarbonate greenhouses. If in a regular greenhouse green spaces can still “breathe” through the cracks in the structure, then in a carbonate one (due to high-quality sealing) they are deprived of this.

But any excess in large quantities always causes harm. If you do not close the doors and windows at night, the plantings will begin to suffer from the cold. And unexpected frosts can destroy the entire crop.

To maintain proper air circulation, you must constantly be on the site and monitor the weather in order to be able to open or cover the greenhouse in time for ventilation. This is not always convenient, especially for a person who has a main job.

But in the age of technological progress, difficult situations can be easily resolved. All the hassle with ventilation will be taken care of by one device. Once it is purchased, installing a thermal drive in the greenhouse in the future will not be difficult. The device can be mounted on the greenhouse door, as well as on built-in windows. Now the responsibility for maintaining the desired microclimate falls on him.

Installing a thermal drive on a greenhouse door or window

What needs to be done to ensure that the thermal drive copes with its task:

• Make sure that the door or window opens without much effort.
• Considering that the rod of the device will extend by 10-12 on its own, you need to mark its location on the doorway or window frame and screw the bracket.
• The spring is fixed on the frame. This will prevent the device and frame from moving to the side.
• The final step is to attach the thermal drive to the ceiling.

Comment! The best place to install a thermal drive is the ceiling of the greenhouse. According to the laws of physics, warm air rises and cold air remains below. This means that the device will operate on time and the plants will not suffer from overheating.

Automatic ventilation machine Thermodrive 300 C

Thermal actuator 300 C - a self-ventilator for a greenhouse - is designed to control the door or window leaf of a greenhouse. Features of the model: steel hinges and rod can withstand loads of up to 300 kg, there are no adjustments or settings, you can open the thermal drive manually and freely use the door, full opening of the sash at a temperature of +26 degrees, ensures effective ventilation, complete closure of the sash at +20 degrees.

Automatic ventilation machine Thermodrive 300 C

Advantages:

• simplicity of design
• ease of installation
• versatility
• nice price

Flaws:

• doesn't always open all the way

Which thermal drive is best for a greenhouse?

If plants are planted in the greenhouse that react sharply to temperature changes, then the best option would be to purchase an electric thermal drive. Sensors adjust the height of the rod that opens the windows in accordance with the warming of the air. The pin lowers and rises smoothly, but in case of sudden cold weather the window will close quickly.

Hydraulic and pneumatic devices are suitable for ventilating greenhouses with tomatoes. Tomato bushes do not like drafts. For normal growth of these plants, smooth air currents are needed. Hydraulic and pneumatic thermal drives operate smoothly. The pin extends as the oil or air inside the device warms up, so that the ventilation is regulated, creating optimal conditions for the seedlings.

Do-it-yourself thermal actuators from car parts or gas lift from an office chair are suitable for large greenhouses. The pins extend with a force of more than 20 kg.

Comment! If the greenhouse is small in size and the windows and doors are light, then there is no need to spend money on expensive devices. You can install a bimetal thermal drive.

DIY thermal drive

A do-it-yourself thermal actuator is often made from improvised means, which do not guarantee either the ease of installation of such a thermal actuator or the ease of its creation.

Think about the fact that before you make a thermal drive yourself, you will spend 5-10 times more time, with absolutely no guarantee that the cost of such a craft will be significantly lower than a purchased ready-made thermal drive with a 3-10 year warranty.

Above are several video examples of such homemade thermal drives. Make sure.

Rating of the best manufacturers

For those who want to save time, purchased options are suitable. Experienced gardeners prefer 5 well-known brands with good characteristics that make thermal actuators for greenhouses.

Dusya San

The device operates on a hydraulic principle, at a temperature not exceeding 50 °C. The operation of the thermal drive does not depend on power. The maximum load that the pin can lift is 7.5 kg.

“Dusya” can be installed in greenhouses of any type. The device is capable of lifting vertical and horizontal windows. When the temperature inside the greenhouse rises to 29 °C, the thermal drive opens the window to the limit.

Sesame-M-2015

The thermal drive operates on the basis of hydraulics. The main element is a black cylinder for quick heating. Machine oil is filled inside. This model runs smoothly. As the pin heats up, it slowly moves out, and when the air cools, it goes inward.

The device is suitable for use in large greenhouses. Capable of opening massive windows or door sashes. The maximum load weight on the movable rod is 12 kg. The kit includes special clamps in the form of hooks that help stop the movement of the pin. If necessary.

Thermal drive

A powerful domestic model that is capable of opening greenhouse doors weighing more than 20 kg. The maximum opening angle is 45°. The device does not look bulky and is easy to install. The work is carried out by hydraulics.

The manufacturer recommends not to overload the device with the heavy weight of the doors. Some elements may become deformed, and the operation of the thermal drive will become incorrect. In addition, it is necessary to monitor the oil level inside the main cylinder.

Open Planet

Using this device, the temperature in the greenhouse can be adjusted from + 14 to + 24 °C. It is believed that these are optimal conditions for the proper development of plants. The device operates on a pneumatic principle.

The manufacturer recommends removing the thermal drive for the winter. There is a possibility of damage to the main cylinder in frosts below - 20 ° C. Open Planet is made of stainless steel, so it is not subject to corrosion. The maximum load is 15 kg.

Comfort AERO100

This ventilation system is designed for areas where winds constantly blow. The mechanism is considered one of the most powerful. The maximum load on the pin is 100 kg. The kit includes reinforced brackets. The force of the spring closing the doors is 6 kg.

The device starts opening windows at 24 °C inside the greenhouse. When reaching 29 °C, the rod extends to its full length. Can be used for greenhouse windows or doors.

Automatic ventilator Thermal drive – reinforced

Thermal drive Reinforced is a hydraulic cylinder that is filled with a special composition with a melting point of 22 degrees. At the same time, the rod extends and opens the attached window or door. Features of a thermal drive for greenhouses: does not limit the ability to open a window, can be installed on a door, can withstand short-term load (wind) on the rod up to 300 kg, to prevent damage to the device by wind, it is recommended to install a limiting cable or chain.

Automatic ventilator Thermal drive – reinforced

Advantages:

• simplicity of design
• ease of installation
• build quality
• equipment
• nice price

Disadvantages: not found

Recommendations for use and care

In order for the thermal drive to serve for a long time and work correctly, you must follow 3 rules:

1. Once a month, inspect the device, lubricate it with oil if necessary, or replace the fluid in hydraulic mechanisms.
2. Avoid rubbing against the greenhouse frame or wall.
3. Remove the thermal drive during periods of low temperatures.

It is not advisable to attach the mechanism to dilapidated frame crossbars. Under heavy load, the automatic closer may jump out of the mount, or the beam may break.

Photo of thermal drive for greenhouses