Just ten years ago, air humidity sensors for fans could afford units. Prices were really wild. But now the situation has changed a bit. This device is quite affordable for everyone.
What is it for, you ask? Everything is simple - to remove excess moisture from the room. This solution is most relevant for the bathroom and the bathroom, where it is usually quite damp, and natural ventilation is not enough. Let's talk about everything in more detail.
Hygrometer selection
It is important to make a good choice. To do this, you must understand that air humidity sensors must meet a number of requirements. The most important thing is accuracy. The correct operation of the element depends on how sensitive the element is, but there is more to come. 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 additional installation work. In principle, the sensor should not be vulnerable to condensation, as well as to harmful chemical effects.
The secondary parameters include the cost and size of the device. Before buying, do not forget to find out about the prices for calibrating a hygrometer, as often a humidity sensor for ventilation can be cheaper than installing and setting it up. 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 air directly depends on its humidity. When the amount of water vapor in the air changes, the capacitance of the condenser also changes. This kind of temperature and humidity sensor can have a more complex design. In this case, the air gap is replaced by a dielectric. This slightly increases the accuracy of the device. The disadvantage of this solution is that when the humidity is below 0.5%, the device is inaccurate. But since in everyday life such an indicator is almost impossible to achieve, for us this is not a significant minus.
Thin-film hygrometers, which incorporate several temperature sensors necessary for thermal compensation, are especially popular. The deviation is allowed no more than 2% with a range of 5-95% relative humidity.
Resistive Hygrometers
Such sensors are based on recording changes in the humidity of a hygroscopic medium. As the hygroscopic element, special substrates, polymers, and the like can be used. As standard, the resistive temperature and humidity sensor consists of a substrate on which two electrodes are applied using a photoresistor. Next, a conductive polymer is coated on the substrate.
The response time of the device is from 10 to 30 seconds, which is quite enough for the bathroom. An indisputable advantage is interchangeability. In addition, such sensors practically do not need calibration. The average life span is approximately 5 years. But this figure is significantly reduced when exposed to chemical vapors, oils, etc. In principle, this is a good solution for domestic use.
Thermally conductive (thermistor) hygrometers
This type of sensor is very different in principle from previous options. The bottom line is that there are several thermistors that are consistent with each other and mounted on a bridge circuit. So, the output voltage is directly proportional to the relative humidity.
Since one thermistor is isolated and the second is open, the current passage time in them is different. The heat transfer 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, thermistors have different resistance. The difference of this indicator characterizes the relative humidity.
It is worth noting that this type of relative humidity sensors are most often used in drying units, microwave ovens, and other household and industrial equipment. In addition to the hygrometers described by us, there are dew point sensors , but they are very expensive and have found their application in the collection of meteorological data.
Digital air humidity sensor: advantages and disadvantages
The advantages of the electronic version are that we purchase a small remote display. We attach it to our sensor. The received information is displayed on the screen. But if making the simplest capacitive air humidity sensor with your own hands is not a problem, then with the electronic version everything is much more complicated. The fact is that digital equipment needs accurate calibration, so you will have to call a specialist for installation. In addition, it is possible to set a timer that will work according to a given program.
It is also worth mentioning 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 nobody is there, the device does not work. In principle, there are a lot of advantages to this solution, but it’s difficult to make an electronic type air humidity sensor yourself. Another significant minus is the lack of ventilation during a power outage.
Humidifier with humidity sensor
The principle of operation of the humidifier is that when the amount of water vapor in the air drops below a certain threshold, the atomizer turns 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 we used the same humidity sensor and fan, then in this case it is necessary to increase the indicator.
The most popular solution is cold humidifiers. The principle of operation of such devices is as follows. Through a humidification cartridge, the fan drives air that is sprayed through a special nozzle. Such aggregates incorporate an electronic sensitive element, which signals when the next spraying is needed.
There is the possibility of automatic operation bypassing the hygrometer. The principle is that the timer sets the frequency of spraying. In this case, there is no need to install relative humidity sensors, which significantly reduces the cost of the humidifier.
Hygrometer is a must for the bathroom
Currently, there are only a few ways to maintain optimal indoor humidity. One of them is a humidifier. But if, for example, in the bedroom you need more humid air, then in the bathroom you should only lower this parameter by removing excess moisture into the ventilation. The bottom line is that when there is a lot of moisture, the device works, when a little - it does not work.
Two modes are available: automatic (the unit turns on itself when the sensor is triggered) and manual (timer operation after a manual start for 2-30 minutes). Such a sensor for measuring air humidity allows you to adjust 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 has poor natural ventilation and the water lingers for a long time. There are many climate companies producing high-quality hygrometers. Let's look at a few models.
Soler & Palau Silent 100 CHZ
The humidity sensor from this global manufacturer is characterized by great stability and a good service life, which reaches 30 thousand hours during 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 inside, which contributes to a more stable and long-term operation of the device. The fan is equipped with a fairly powerful electric motor with a check valve, which ensures a good outflow of moist air. The device is turned on automatically through an electronic sensor. All elements are reliably protected from condensation, therefore the actual service life is practically the same as indicated in the instructions. The cost of this unit ranges from 6-7 thousand rubles.
Overview Maico ECA Piano H
The products of the German company Maico are famous for their accuracy and reliability. Such a fan with a humidity sensor costs a lot. This is due to the fact that the casing is made of shockproof plastic, the electric motor is equipped with a system of protection against overloads and accumulation of condensate. A powerful fan along with a high-precision humidity sensor ensures reliable outflow of air from the room.
We can say with confidence that the Maico ECA Piano H is suitable for use both in a small storage room or bathroom, as well as in the office or general shower. It is worth paying your attention to the fact that the air humidity sensor for the fan in this device responds to a change in relative humidity of 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 is safe to say that at present there is a huge selection of hygrometers. Some air humidity sensors are only suitable for industrial use, while others are only suitable for domestic use. 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 the simplest capacitive sensors with a service life of not more than 10 thousand hours.
Mid-range models, such as Elicent ELEGANCE, will cost about 8-10 thousand rubles. In return, you will receive an aggregate with a working resource of about 30 thousand hours.
Sensors with fans in the high price range, costing about 20-30 thousand rubles, are exclusive solutions that fit any room design. 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 air humidity sensors in the bathroom. This is due to the fact that the device will pump out moist air and thereby cool the room. In this case, it would be logical to provide good ventilation. To do this, you can make a lattice in the door leaf, which will be quite enough. In order not to get sick, you can slightly change the circuit and make the fan work only when there is nobody in the room. But in this case, the timer on the unit will not work.
In principle, it is rational to install a digital temperature and humidity sensor in vegetable stores and cellars, where there is a need to maintain humidity and temperature at a certain level.
Conclusion
You have learned quite a lot of useful information about what an air humidity sensor is. The price of such equipment may vary depending on power, functionality, dimensions and other parameters. Such a purchase is not cheap, so first evaluate how much you need the described device. If a fungus begins to appear in the bathroom or the bathroom due to increased moisture and normal ventilation does not help, a hygrometer mounted on a fan will be very useful. In some cases, the problem is solved by an electric fan, which must be turned on and off manually. It is much cheaper and almost no worse.