What are the humidity sensors for the fan? How to choose a temperature and humidity sensor

Literally ten years ago, humidity sensors for fans could afford units. The prices were really wild. But at the moment the situation has changed somewhat. This is quite affordable for each device.

What is it for, you ask? It's simple - to remove excess moisture from the room. The most relevant solution for a bathroom and a bathroom, where it is usually quite damp, and natural ventilation is not enough. Let's talk about everything in more detail.

Choosing a Hygrometer

It is important to make a good choice. To do this, it is necessary to understand that the humidity sensors must meet a number of requirements. The most important thing is accuracy. On how sensitive the element will be, its proper work depends, but it's not all yet. It is important to purchase an interchangeable element, that is, one that can be removed without problems in the event of a breakdown and install another without performing additional installation work. In principle, the sensor should not be vulnerable to condensation, and also to harmful chemical attack.

Secondary parameters include the cost and size of the device. Before buying, do not forget to learn about the prices for the calibration of the hygrometer, as often the humidity sensor for ventilation can cost less than its installation and adjustment. And now let's look at the main types of hygrometers.

Capacitive sensors

The device is a capacitor with an air gap. The bottom line is that the dielectric constant of the air depends directly on its humidity. When the amount of water vapor varies in air, the capacitance of the condenser also changes. This type of temperature and humidity sensor can have a more complex design. In this case, the air gap is replaced by a dielectric. This somewhat increases the accuracy of the device. The disadvantage of this solution is that with a humidity below 0.5% the device is inaccurate. But as in the life of such an indicator is almost impossible to achieve, for us it is not a significant disadvantage.

Especially popular are thin-film hygrometers, which have in their composition several temperature sensors, which are necessary for thermal compensation. The deviation is not more than 2% with a range of 5-95% relative humidity.

Resistive hygrometers

Such sensors are based on the fixation of moisture changes in a hygroscopic medium. As a hygroscopic element, special substrates, polymers and the like can be used. In the standard version, the resistive temperature and humidity sensor consists of a substrate on which two electrodes are applied using a photoresistor. Next, the conducting polymer is covered with a substrate.

The response time of the device is from 10 to 30 seconds, which is quite enough for a bathroom. Unquestionable advantage - interchangeability. In addition, such sensors practically do not need calibration. The average expiration date is approximately 5 years. But this figure is significantly reduced when the sensor is exposed to chemical vapors, oils, etc. In principle, this is a good solution for operation in domestic conditions.

Thermal (thermistor) hygrometers

This type of sensor is very different in principle from the previous options. The bottom line is that there are several thermistors that are matched to each other and mounted on a bridge circuit. Thus, the voltage at the output is directly proportional to the relative humidity of the air.

Since one thermistor is isolated and the other is open, the time of the current flow in them is different. The heat output of a sealed thermistor is many times greater than that of an open one. This is achieved by using dry nitrogen as an insulator. Due to the fact that heat creates different temperatures, the thermistors have different resistance. The difference in this indicator characterizes the relative humidity.

It is worth noting that the sensors of relative humidity of air of this type are most often used in drying units, microwave ovens and other household and industrial equipment. In addition to the hygrometers we described, there are dew point sensors , but they are very expensive and have found their application in the collection of meteorological data.

Digital Humidity Sensor: Advantages and Disadvantages

The advantages of the electronic variant are that we acquire a small remote display. We attach it to our sensor. The information received is displayed. But if the simplest capacitive humidity sensor is not a problem to make with your own hands, then the electronic version is much more complicated. The fact is that digital equipment needs accurate calibration, so you'll have to call a specialist for installation. In addition, it is possible to set a timer that will work according to the specified program.

Still it is necessary to say that electronic hygrometers can be equipped with a motion sensor. The latter works as follows: when someone enters the bathroom, the fan turns on automatically when no one is present, the device does not work. In principle, there are many advantages to such a solution, but it is difficult to manufacture an electronic humidity sensor for your own hands. Another significant disadvantage is the lack of ventilation when power is cut off.

Humidifier with humidity sensor

The principle of the humidifier is that when the amount of water vapor in the air falls below a certain threshold, the nebulizer is turned on. This solution is implemented through a mounted humidity sensor. Most often it is capacitive or electronic with a deviation of 2%. If earlier we needed to lower the humidity, for which the same humidity sensor and fan was used, then in this case it is necessary to increase the index.

The most popular solution is cold humidifiers. The principle of operation of such devices is the following. Through the humidifying cartridge, the fan blows air, which is sprayed through a special nozzle. Such units have an electronic sensor in their composition, which signals when the next spraying is needed.

There is the possibility of automatic operation bypassing the hygrometer. The principle is that the periodicity of spraying is set on the timer. In this case, there is no need to install a relative humidity sensor, which significantly reduces the cost of the humidifier.

Hygrometer is the need for a bathroom

At present, there are only a few ways to maintain optimum humidity in the room. One of them is a humidifier. But if, for example, in the bedroom you need more moist air, then in the bathroom you should only lower this parameter by removing excess moisture in the ventilation. The bottom line is that when there is a lot of moisture, the device works, when not enough - it does not work.

Two modes are available: automatic (the unit switches itself on when the sensor is triggered) and manual (timer operation after manual start for 2-30 minutes). Such an air humidity measurement sensor allows to regulate the fan speed, which directly depends on humidity. The higher it is, the cooler works faster, and vice versa. This is a good solution if the room is poorly ventilated and the water is delayed for a long time. There are a lot of climatic companies producing high-quality hygrometers. Let's look at a few models.

Soler & Palau Silent 100 CHZ

The humidity sensor from this world manufacturer is characterized by great stability and good service life, which reaches 30 thousand hours in normal operation. The advantage of this solution is that the fan with the sensor can be installed in any position, which is sometimes extremely necessary.

The body of the product is protected from moisture ingress, which contributes to a more stable and long-lasting operation of the device. The fan is equipped with a fairly powerful electric motor with a non-return valve, which ensures a good outflow of moist air. The device is switched on in automatic mode via an electronic sensor. All elements are reliably protected against condensation, therefore the actual service life is practically the same as specified in the instruction. The cost of this unit fluctuates around 6-7 thousand rubles.

Overview Maico ECA Piano H

The products of the German company Maico are famous for their precision and trouble-free operation. Such a fan with a humidity sensor is worth a lot. This is due to the fact that the body is made of impact-resistant plastic, the motor is equipped with a system to protect against overloads and condensation. A powerful fan along with a high-precision humidity sensor ensures a reliable outflow of air from the room.

It's safe to say that the Maico ECA Piano H is suitable for use in a small storage room or a bathroom, or in an office or common shower. It should be noted that the air humidity sensor for the fan in this device reacts to a change in relative humidity by 1-2%. In principle, this is a great solution for good money. The cost of the device is 16 000 rubles.

What is the price of a good humidity sensor?

It can be said with certainty that at present there is a huge choice of hygrometers. Some humidity sensors are suitable only for industrial use, others are for household use only. So, the prices for the simplest household appliances start from 4 thousand rubles. For this money, you should not rely on high-precision hygrometers. As a rule, these are simple capacitive sensors with a service life of no more than 10 thousand hours.

Models of the average price range, such as Elicent ELEGANCE, will cost about 8-10 thousand rubles. In return, you will receive an aggregate with a service life of about 30 thousand hours.

Sensors with fans of a high price range costing approximately 20-30 thousand rubles are exclusive solutions that are suitable for any design of a room. In addition, such devices have a power regulator, so they are suitable for both large and small rooms.

A few important points

Of course, it should be noted that it is far from always rational to install sensors for humidity in the bathroom. The reason is that the device will pump out moist air and thereby cool the room. In this case, it would be logical to ensure good supply ventilation. To do this, you can make a lattice in the door leaf, which is quite enough. In order not to get sick, you can change the scheme a little and make the fan work only when there is no one in the room. But in this case the timer on the unit will not work.

In principle, the digital temperature and humidity sensor is rationally installed in vegetable stores and cellars where there is a need to maintain the humidity and temperature at a certain level.

Conclusion

You've learned quite a lot of useful information about what an air humidity sensor is. The price of similar equipment may vary depending on the capacity, functionality, dimensions and other parameters. Such a purchase is not cheap, so first of all, evaluate how much you need the device described. If a fungus begins to appear in the bathroom or bathroom due to high humidity and normal ventilation does not help, a hygrometer mounted on the fan will be very useful. In some cases, the problem is solved by a fan with an electric drive, which must be turned on and off manually. It is much cheaper and almost nothing worse.