Oil temperature regulator for greenhouses. Thermostat for a greenhouse is an important help in increasing productivity

When constructing a greenhouse, it should be remembered that in order to maintain proper growth conditions for various crops, it is necessary to install special equipment (for example, a stove that can run on different fuels) that provides heating. But this is not enough, since the heating of air, water and soil must be controlled and the system must be turned on and off. The thermostat, which is installed inside the greenhouse, is designed for this purpose.

A thermostat helps control the temperature in the greenhouse and control turning the heating system on and off.

Any DIY greenhouse heating requires careful monitoring of conditions day and night. Boilers or other heating devices must operate in different modes, depending on the design of the greenhouse and the conditions of use (whether it is winter or summer). The selection of temperature conditions is influenced by the heated areas of the greenhouse and the types of crops. Therefore, the water heating scheme for the greenhouse must be selected individually. If desired, solid fuel boilers can also be used for heating.

If manure is used to heat the soil, soil temperature sensors should be connected to the thermostat.

Types of thermostats for greenhouses: from touch to mechanical

You can assemble the thermostat yourself or buy a ready-made one in a specialized store. Manufacturers today offer a temperature controller that can work in large and medium-sized polycarbonate greenhouses. The following models are available:

A modern touch-sensitive temperature controller, which is used for large systems, is distinguished by its reliability and the ability to quickly set any program that regulates heating. Such equipment is equipped with many functions; the temperature controller can be used even at night; its display is backlit. He also takes into account soil heating due to manure. To do this, you need to make the appropriate settings.
The electronic thermostat is equipped with an LCD display, which displays all the necessary information. As a result, heating of the greenhouse will always correspond to the established indicator.
A mechanical thermostat is the simplest, but no less effective device.

When purchasing a device such as a thermostat for a greenhouse, you need to pay attention to:

on the power of the unit, on boilers and their capabilities;
installation features that the thermostat may require;
availability of all required functionality;
appearance and control.

For polycarbonate greenhouses, external and hidden thermostats are applicable, which are mounted in different ways in the room, controlling heating. It is also worth considering the fact that manure is often used to heat the soil, and solid fuel boilers or other heating devices are used only for the winter months, when the air temperature can drop significantly. A water heating circuit, which can be powered by electricity, is also effective here (that is, solid fuel boilers are not always used).

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Purpose and principle of operation

All heated greenhouses must have not only boilers for heating, but also means for controlling the microclimate and the operation of the stove. The thermostat helps maintain a greenhouse made of polycarbonate and any other material at a certain temperature that allows the plants to feel comfortable. As already noted, manure can be used to heat the soil, but a water heating scheme is used to heat the air and water for irrigation.

The choice of any of these methods must be approached thoroughly, taking into account all the prospects of such methods.

The principle of operation of the device is quite simple: a signal is sent to the boiler to increase or decrease power. Receiving this signal through a relay is provided by a thermostat, which collects all data from sensors located throughout the greenhouse.

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Thermostat diagram for a polycarbonate greenhouse

The temperature controller for the greenhouse operates from two sensors: temperature and light directly. This must be taken into account, since the room temperature is lower at night and higher during the day. In accordance with this, the heating conditions also change. The main parameters that a thermostat must have are the following:

temperature range – +15-50°C;
accuracy – 0.4°C;
illumination threshold – 500-2600 lux;
the difference in ambient temperature when crossing the illumination threshold is up to 12°C;
Permissible deviations when powering the device are up to 20%.

The thermostat for a greenhouse consists of a temperature control unit and a correction unit, which can be done using transistors. The switch allows you to change the temperature value for the greenhouse in accordance with the required growing conditions for certain crops. The relay for power control can be connected by contacts to a heating device for the stove. The temperature controller has an output relay that controls all heating.

Greenhouse sensors include thermistors and photoresistors that respond to changes in external conditions. They are especially good for use in winter greenhouses where conditions need to be carefully monitored. All relevant settings, including soil heating from manure, can be set according to the instructions provided by the device manufacturer.

They begin to set up the heating device using their own hands, by calibrating the resistor scale. This is easy to do: sensors are placed in heated water, allowing you to accurately determine the temperature. After this, the light sensor is calibrated. This can only be done with those lighting fixtures that are intended for a greenhouse (all photoresistors are very sensitive and spectrally dependent). Then the temperature controller can be assembled and mounted inside the greenhouse; it should be located close to the stove or other heating device, but being isolated from it (an uninsulated boiler can interfere with incoming data).

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How to work with a thermostat?

As a rule, all thermostats for a greenhouse are similar to each other. This is a special compact electronic device with which you can regulate the heating of polycarbonate greenhouses. The thermostats are designed in such a way that they are very convenient and easy to work with. The main steps are as follows:

Scroll through the menu using the corresponding button.
Setting the parameters necessary for heating the greenhouse.
Possibility of manual temperature control (suitable if you need to heat the greenhouse in winter or on cold nights in summer).
Display with readings. It displays data about the current heating (for the stove and for the air), operating time and shutdown.
Using special buttons, you can set any heating parameters and regulate the operation of the stove and boiler.
Ability to save selected settings to memory for quick activation.

In addition, using a thermostat, you can control the boiler for heating the greenhouse. The algorithm of actions is as follows:

When power is applied to the controller, all sensors are polled for real-time information. The controller compares the readings with the recorded data for night or day mode, and then selects the correct settings for the operation of the thermostat in the room.
After about five seconds, the thermostat is activated, and the boiler, installed to heat the room and maintain the required temperature, begins its operation.
When the temperature on the sensors in the polycarbonate greenhouse remains below the required one, that is, the existing heating is insufficient, the pump and heater come into operation, and a command is sent to the corresponding unit to increase the fuel supply so that the heating of the system begins to work actively.

Each thermostat is equipped with a special circuit that allows it to act in emergency situations:

When the coolant temperature is higher than the specified parameters, the pump turns on and the heater turns off, water begins to flow through the boiler (when installing water heating, if solid fuel boilers are used, the diagram may be different).
If any sensor fails, the circuit is considered offline and all pumps and heaters are turned off approximately 30 seconds after the signal is given.
If the boiler is working and the coolant temperature sensor is faulty, then the boiler itself is switched to the minimum operating mode or switched off with a corresponding signal.

A thermostat is a special device that is used to install a heating system for a greenhouse. The device is multifunctional; with its help you can not only set the required temperature to heat the air in the room, but also provide heating of water for irrigation and soil (here it is possible to use manure).

The modern greenhouse temperature controller has the ability to maintain the set conditions for any polycarbonate greenhouse with fine and precise control. Many thermostats in polycarbonate greenhouses turn on independently if the set conditions do not correspond to those that exist at a given time. The temperature controller for the greenhouse is connected to the controller and sources that heat the room. Manufacturers usually offer detailed installation instructions.

The temperature controller, which is installed indoors (even if manure is allowed to heat the soil), is connected to all installed heat sensors, controller, boiler and stove that provide heating. The result is complete temperature control.

These days there are a large number of thermostats on the sales market. These are very convenient devices that are also used when working in a greenhouse. They will help maintain the temperature of the air and soil in the room. Which will save the owner from unnecessary work.

A large number of types of thermostats sometimes make it difficult to select the right device. Before purchasing, you should know their differences and features in order to make the right choice.

Division by type

Thermostats are divided into three types, which differ in their functionality.

Mechanical thermostat that will maintain soil temperature. This is the simplest and cheapest design. It allows you to set the temperature once and subsequently have the opportunity to adjust it. After heating, the thermostat activates, which turns off the system. You just have to do the adjustment yourself. This thermostat is suitable for small spaces.
The electronic thermostat is a more advanced design, which is equipped with an LCD display, allowing you to more accurately control the temperature in the greenhouse room.
Touch thermostats are the latest developments in electronic thermostats that allow you to set an operating program. This is a more advanced and reliable design. It is equipped with additional functions and options that will help create the desired temperature in the room and soil, even at different times of the day.

Selecting a thermostat

When choosing such an element, you should decide what you want to get. Please note the classification of this equipment.

Please note:

Power;
Installation features;
Device control type;
Pay attention to the number of functions provided;
Appearance.

Pay special attention to power. It will be needed when heating the soil. Determine the heating power of the soil; the thermostat should exceed it; it should be selected with a reserve.

Or it is possible to install several thermostats, in which case you will need to divide the greenhouse room into zones (see).

All work of the system is carried out using sensors, from which it receives all the necessary information.

Sensors are:

Hidden;
External.

Several elements may be involved in the entire chain.

The thermostat can be of different appearance. The installation method is hidden and mounted.

Many summer residents do not need a thermostat, which has many functions. Often they just need to warm up the soil a little in the spring. To perform such work, a device that you can make with your own hands is quite suitable.

What is it for?

The thermostat for greenhouses in the proposed design can be useful for any greenhouse. It can constantly maintain one specific temperature (see in more detail:). This is especially true in early spring, when the weather is so changeable. It can constantly maintain the same temperature by interacting with heating and cooling devices. It does not require searching for expensive parts and is quite simple to manufacture.

Some features of devices of this type should be taken into account:

Such devices are subject to self-generation, that is, they can self-excite. This can happen if the device is located too close to the main device, then the triggers can occur spontaneously. If you are near a heating or cooling device, self-triggering can occur. The location of the device must be chosen correctly.
These devices do not have great accuracy. Sometimes it can be quite difficult to determine at what temperature the device should operate. Sometimes electronics can make the wrong decision.

Operating principle

This scheme takes into account all the basic needs for heating the soil and ventilating the greenhouse premises.

Here the role of the sensor is played by a thermistor; its resistance decreases when heated. It is included in the circuit along with a voltage divider;
A variable resistor is included in the circuit; it sets the temperature at which the thermostat turns on;
The thermostat senses the increase in temperature and sends a signal to turn on the fan or other cooling unit. The resistance value at this moment is at a minimum;
During operation of the cooling device, the resistance increases and the voltage level in the divider increases;
When the maximum resistance level in the resistor is reached, the transistor operates and the capacitor begins to charge. After all elements of the circuit are activated, the fan automatically turns on.

Self-generation is eliminated using blocks that set a temporary switch-on delay. The delay time is equal to the charging time of the capacitor.

Such non-standard regulators are widely used when heating the soil.

When installing the system yourself, you need to know that the thermostat includes an adjustment unit and a temperature control unit.

They can be performed using transistors. A switch allows you to vary the temperature.

The relay can be connected to the heating device for the stove using contacts. The regulator may have an output relay that controls heating.

Homemade thermal drive for greenhouse ventilation

You should set up the installation yourself, starting with calibrating the resistor scale. First, the sensors are lowered into heated water, and then the temperature is determined.

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In such cases, you can use cheaper and rather ordinary methods that can effectively lower or increase the temperature.

In addition, it should be noted that some of them are more effective compared to modern technical devices.

Using touch thermostats, you can set a certain operating time for the heating system. In addition, at different times you can set different, most suitable temperatures.

Such devices are usually programmed for a fairly long period of time - it is possible to set the desired mode for a week, and in some models for longer.

Thermostat for heated floors, incubators, electronic thermostat with temperature sensor

Reviews:

Timur Dakaev writes: does it accurately show the temperature or are there errors?

Sasha Popov writes: what camera did you use?

Alex K. writes: Greetings. Does this thermostat have memory? Those. If the electricity goes out and then turns on, will the temperature we set be reset or will the setting remain?

Frank Kauperwood writes: It’s bad that he constantly twitches, the light bulbs will burn out often often

Chirchik writes: HOW MUCH DOES THIS REGULATOR COST?

How timely your article appeared. Just today in our forum of amateur gardeners, we discussed how to automatically ventilate polycarbonate greenhouses. After all, everything is good in them, but in the heat the problem is that it is not always possible to open, because many people are working.

Note! Such electronic thermostats are becoming increasingly popular because they have the ability to sense the temperature at any point inside the greenhouse, and the monitoring sensor can be placed between the plants, in the soil substrate, or suspended near the roof. Such a wide range of placement allows the thermostat to have accurate data on the state of the internal environment of the greenhouse.

The ideal mechanism would be one based on a converted factory relay.

The work is carried out on the principle of an electromagnet, where the armature is drawn into a coil. The switch (2A, 220V) controls the electromagnetic starter to supply power to the heating devices.

DIY SOLDERING IRON TEMPERATURE REGULATOR

Reviews:

Vsevolod Ukrainian writes: Tell me, or post a link to how to use a regular soldering station, to make an indicator of the temperature of the soldering iron from a regular cheap 3-segment Chinese volt-ampere meter. At the station itself there is a regulator, but there is no electronic display.

Mikhail Pushkin writes: the electrolyte will explode

Franchesko writes: Water)

The JUSED writes: I like BT or BTA better on Simsra, but for beginners it is more difficult

Lechoslowianin writes: Talking too fast

In industrial greenhouses, a whole system of sensors monitors the stability of the microclimate. In private buildings, plants have to be saved from heat or cold manually - through ventilation or regulation of the heating system. Round-the-clock maintenance is not only tiring, but also tightly ties the summer resident to the beds, so sooner or later he has to think about whether it is possible to make a thermostat for the greenhouse with his own hands, and how reliably it can function.

It would seem, why not purchase a ready-made device, since there are many models on the market today, the price of which starts from 400 rubles? In fact, branded controllers, the reliability of which you can trust, are expensive, and cheap analogues can fail at the most crucial moment, which can lead to the loss of the entire harvest.

By assembling and testing the thermostat yourself, you can both save money and be safe from its failure.

Automatic thermostat from the manufacturer

How to achieve the main goal - adjusting the temperature inside the greenhouse automatically? The simplest way to do this is to open and close the windows at the right time.

Timely ventilation helps keep the air temperature in a certain range that is comfortable for the normal growth and fruiting of cultivated crops.

A lot of devices have been invented to automatically open windows: some of them are made from scrap materials - plastic bottles, empty cylinders; others require you to stock up on some parts in advance, such as a car gas shock absorber. In both cases, the price of the device is minimal, but the level of its response will need to be checked quite often.

Ventilation is a common method of thermoregulation

Classic greenhouse thermostats, if necessary, limit the access of the coolant to the heating elements or, conversely, contribute to a rapid increase in temperature. Thus, hypothermia and overheating of plants are excluded, and excess energy is not wasted. This significantly reduces the cost of heating the greenhouse, so this method of microclimate control is preferable.

The principle of their operation, regardless of type, is to process the readings of one or more temperature sensors and transmit a signal to the actuator of the heating system, which then either reduces the operating power or increases it.

To create such a thermostat for a greenhouse with your own hands, you need knowledge of electronics and skills in assembling electrical circuits.

Homemade thermostat assembly

Video: How to assemble a thermostat yourself

Installation of temperature control devices - mechanics and electronics

It is ideal when thermostats complement the work of transom thermal drives: in winter they turn the heating off and on, and in summer the microclimate is controlled by opening and closing the vents. Thus, a summer resident can devote much less time to his greenhouse without fear for his harvest.

Pneumatic thermostat – removal of excess heat

The pneumatic device, the action of which is based on the ability of hot air to expand, is easy to assemble and at the same time allows you to solve the problem of thermoregulation for a long time. For its installation the following elements are required:

2 tin paint cans with a capacity of 5–7 liters (with lids);
several tubes from medical IVs;
children's inflatable ball with a coverage of about 300 mm;
thin plywood with a width of at least 300 mm;
metal strips (strips) of arbitrary size;
3 copper tubes 50 mm long.

Schematic diagram of the pneumatic regulator

Assembling the thermal drive involves performing a few simple steps:

Seal the cans by soldering or pouring epoxy resin.
Drill one hole to fit the copper tubes in one container and two in the other.
Insert the tubes into the holes and seal the joints.
Make a box measuring 300x300 mm from plywood. Leave it open on both sides.
Cut the plywood plate to the dimensions that best fit the cavity of the box.
Insert the plate inside the box and secure it with hinges.
Attach the box with the open part to the window.
Make a movable lever from two metal strips, one arm of which is rigidly attached to the window, and the other to the movable plate of the plywood box.
Close the window and check the position of the plate - its angle of inclination relative to the walls of the box should be 45 degrees.
Hang tin containers under the roof and connect them with tubes from the droppers, while the length of the outgoing tube should cover the distance from the cans to the box.

You need to close the entire system into a single mechanism in cool weather or in the evening. To do this, you need to put the ball in the box and inflate it exactly until the moment when, with further air injection, it begins to open the window.

After this, you should tightly connect the end of the outgoing tube with the ball and check the operation of the device when it warms up.

Pneumatic system in a different version

Thermostat made from a gas shock absorber

By slightly modifying the pneumatic shock absorber from any passenger car (these are usually installed on hoods or rear doors), you can get a device that can automatically open a transom or window, thereby eliminating excess thermal energy.

The spare part does not have to be new - it is enough that there is pressure in it. You also need to stock up on a brake hose and an empty car fire extinguisher in advance.

You can mount these parts into a single device as follows:

Without breaking the tightness of the pneumatic cylinder, cut off the spherical part of its shank, leaving the maximum length.
From the side of the formed end, drill a hole with a diameter of 2–3 mm to bleed air from the cylinder cavity.
Cut a thread on the shank (its pitch depends on the size of the thread on the existing brake hose).
Use a fire extinguisher (or a 3-liter car universal joint) to build an oil tank with a connecting hole for a hose.
Pour oil into the shock absorber and into the reservoir, then connect them with a hose.

After installing the thermostatic system, test its functionality by temporarily increasing the heating power.

Homemade pneumatic regulator in a greenhouse

Miracles of electronics - assembling a regulator from a household thermometer

To get your own thermostat for a greenhouse, which controls the air temperature in a constant mode and transmits a signal about the need to change the operation of the heating system, you need to modify a regular dial thermometer:

Disassemble the temperature sensor so as not to damage it.
Drill a hole with a diameter of 2.5 mm in the scale - in the area of the required temperature limit.
Opposite it, construct a corner from thin sheet metal with a 2.8 mm hole drilled in it.
Install the phototransistor into the corner socket and attach them to the scale using Moment glue.
Secure another corner under the hole to prevent the arrow from moving as the temperature rises.
Install a 9 V light bulb on the opposite side of the thermometer. You can put a lens between the scale and the light bulb - this way the device will respond more accurately to the indicators.
Route the photocell wires through the central hole of the thermometer scale.
Drill a hole in the housing for the light bulb wires. Thread the tourniquet into the vinyl chloride sheath and secure with a clamp.
According to the standard scheme, assemble a voltage stabilizer and a photo relay with a GT109 transistor.
Place the photo relay, power supply and temperature sensor on the base of the factory relay mechanism.
On the outside of the common body, attach a toggle switch and a neon light to signal the start of heating.

Dial thermometer for greenhouse

A homemade thermostat for a greenhouse operates on the principle of an electromagnet: a steel armature is pulled into a coil, and a switch (with a current of 2 A and a power of 220 V) activates an electromagnetic starter that supplies power to the heating devices.

Thermostat assembly diagram

The main disadvantage of an electronic thermostat for a greenhouse is its dependence on a source of electricity. If the power goes out during extreme heat or cold, you can lose all your plants.

The temperature regime, which is formed and regulated by several systems at once - heating, ventilation, air humidification, evaporative cooling and others - plays a major role.

For constant control with the possibility of adjustment, an air temperature regulator in the greenhouse is used, which is an important element, since even a slight change in indicators can have a detrimental effect on the plants, even to the point of their death.

Compliance with the temperature regime in the greenhouse is the key to high yields

As a rule, for most plants the most comfortable temperature is within from 16 to 25 °C, and a deviation of even a degree, even if it does not lead to the death of the plants, their appearance will be very eloquent: in this case, symptoms of wilting begin to appear.

It is important to regulate not only the air temperature in the greenhouse, but also the soil temperature. The interaction of these two indicators determines the speed and intensity of the absorption of nutrients from the soil; accordingly, they directly affect the growth and development of plants.

The optimal soil temperature is almost in the same range as from 13 to 25 °C and is determined, as a rule, by what kind of crop is grown.

Attention! Temperature changes in the soil are sometimes even more noticeable for plants. For example, a decrease slows down or stops vegetation, and an increase affects the absorption of moisture by plants.

Ways, methods and devices for regulating temperature in a greenhouse

The most convenient option: make automatic temperature control in the greenhouse, taking into account the readings of sensors connected to all systems. For this purpose, various models of automatic regulators are used.

Some of the modern models have programming capabilities:

for a specific type of plant;
for day and night modes;
with the possibility of SMS notification, etc.

On such models, all information is displayed on the display, and making adjustments, programming or reprogramming is easy and quick, thanks to the intuitive menu.

Advice. It is economically unprofitable to buy an expensive system in private ones. In this case, for example, a mechanical device or a homemade temperature controller in a greenhouse can be successfully used, which, meanwhile, cope successfully.

How to choose the right thermostat

A correctly selected regulator (thermostat) must take into account several factors.

The power of the device, which should be:

sufficient and consistent with the power of the heating system;
fit the size of the greenhouse;
be complete or compatible with the sensors and their number required.

Ease of installation and operation:

functionality of the device:programming; control; control of current parameters;degree of autonomy.
timing of installation work.

How the thermostat works and works

Any thermostats for – temperature control unit based on readings from connected sensors. You can assemble such a device yourself. To do this, you can use a thermostat circuit for a greenhouse, presented in professional literature and on specialized websites on the Internet.

All thermostats, even those assembled by yourself, operate on the following principle: the device sends a signal, processed based on sensor readings, to a system, such as a heating system, to increase or decrease power.

How to properly configure the device

For a self-assembled device using sensors, it is necessary to carry out the so-called adjustment process. In this case, the instructions must be strictly followed, according to which the process is reduced to calibrating the resistor scale.

The essence of the setup is as follows:

sensors are placed in heated water with a known temperature;
based on the data, the scale is calibrated and synchronized;
After this, the sensors can be installed and connected to the thermostat.

A simple, affordable and effective way to regulate temperature

For summer residents who have greenhouses on their property, but visit them only once a week, it is rational to assemble a device whose price, compared to industrial analogues, is significantly lower. However, such devices meet all the requirements placed on them; they are reliable and accurate.

The power source for them is solar energy, and the air acts as a sensor. The regulator is a housing divided into sectors made of duralumin, an inspection cover with a pusher link and a rotary valve.

Next is an expansion tank connected to a rubber chamber, for example from a ball. When the air is heated above 25 °C, the chamber is filled, which, in turn, opens the transom of the greenhouse to the appropriate width. When the temperature decreases, the reverse process occurs.

How to quickly change the temperature in a greenhouse in emergency conditions

To regulate the temperature in greenhouses, especially in small home or country houses, it is often necessary to use some other available methods.

As a rule, such measures are relevant when there is an emergency need to increase or decrease temperatures, for example, during the off-season.

The temperature can be easily increased, for example, by one of the following methods or in combination:

covering with an additional layer of film,
the use of a portable structure under which plants are sheltered in the greenhouse itself,
use of soil covering products, such as manure, film, etc.

Activities such as:

provide sufficient access to fresh air;
spray the greenhouse with chalk solution;
in summer, water and spray plants early in the morning, immediately after sunrise.

Conclusion

For each greenhouse, the calculation and diagram of temperature controllers must be done separately, depending on the design of the room, heaters, fans and crops that will be grown. Some options can be seen in the video in this article.