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

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

Literally ten years ago, few could afford air humidity sensors for fans. The prices were really wild. But now the situation has changed somewhat. It's an affordable device for everyone.

What is it for, you ask? It's simple - to remove excess moisture from the room. This solution is most relevant for the bathroom and toilet, 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, it is necessary to understand that air humidity sensors must meet a number of requirements. The most important thing is accuracy. How sensitive the element will be depends on its correct operation, but that's not all. It is important to purchase an interchangeable element, that is, one that can be easily removed in the event of a breakdown and installed another without additional installation work. In principle, the sensor should not be vulnerable to condensation, as well as to harmful chemical attack.

The secondary parameters includethe cost and size of the device. Before buying, do not forget to find out about the prices for calibrating a hygrometer, since often a humidity sensor for ventilation can cost less than installing and configuring it. Now let's look at the main types of hygrometers.

Capacitive sensors

The device is an air gap capacitor. 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 capacitor also changes. This kind of temperature and humidity sensor may 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 at humidity below 0.5% the instrument is inaccurate. But since it is almost impossible to achieve such an indicator in everyday life, this is not a significant minus for us.

Thin-film hygrometers are especially popular, which incorporate several temperature sensors needed for thermal compensation. A maximum of 2% deviation is allowed within the range of 5-95% RH.

Resistive hygrometers

This kind of sensors are based on fixing changes in the humidity of a hygroscopic medium. As a hygroscopic element, special substrates, polymers, etc. can be used. In the standard version, a resistive air temperature and humidity sensor consists of a substrate, on which, with the help ofphotoresistor impose two electrodes. Then the substrate is covered with a conductive polymer.

The response time of the device is from 10 to 30 seconds, which is quite enough for the bathroom. The undeniable advantage is interchangeability. In addition, such sensors practically do not need to be calibrated. The average service life 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 domestic use.

Heat-conducting (thermistor) hygrometers

This type of sensors 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 in a bridge circuit. Thus, the output voltage is directly proportional to the relative humidity of the air.

Because one thermistor is insulated and the other is open, the current flow 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 relative humidity sensors of this type are most often used in drying units, microwave ovens and other household and industrial equipment. In addition to the hygrometers we have described, there are sensorsdew points, but they are very expensive and have found their way into the collection of meteorological data.

Digital humidity sensor: advantages and disadvantages

The advantages of the electronic version are that we get a small remote display. We attach it to our sensor. The received information is displayed on the screen. But if it’s not a problem to make the simplest capacitive air humidity sensor with your own hands, then with the electronic version everything is much more complicated. The fact is that digital equipment needs to be accurately calibrated, 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 there is no one, the device does not work. In principle, such a solution has a lot of advantages, but it is difficult to make an electronic type air humidity sensor with your own hands. Another significant disadvantage 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 before we needwas to lower the humidity, for which the same humidity sensor and fan were used, 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. A fan blows air through the humidifier cartridge, which is sprayed through a special nozzle. Such units incorporate an electronic sensing element that signals when the next spray is needed.

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

A hygrometer is a must for the bathroom

Currently, there are only a few ways to maintain optimal indoor humidity. One of them is a moisturizer. But if, for example, a bedroom needs 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 there is 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 manual start for 2-30 minutes). Such an air humidity measurement sensor allows you to adjust the fan speed, which directly depends onhumidity. The higher it is, the faster the cooler works, and vice versa. This is a good solution if there is poor natural ventilation in the room and the water lingers for a long time. There are a lot of climate companies that produce 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 good service life, which reaches 30 thousand hours in normal use. The advantage of this solution is that the fan with 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-term operation of the device. The fan is equipped with a fairly powerful electric motor with a check valve, which provides a good outflow of moist air. The device is switched on automatically through an electronic sensor. All elements are reliably protected from condensate, so the actual service life practically does not differ from that indicated in the instructions. The cost of this unit fluctuates around 6-7 thousand rubles.

Review Maico ECA Piano H

Products of the German company Maico are famous for their accuracy and uptime. Such a fan with a humidity sensor costs a lot. This is due to the fact that the case is made of impact-resistant plastic, the electric motor is equipped with a system of protection against overloads and accumulation of condensate. Powerful fan along with high precision sensorhumidity 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 bathroom, as well as in an office or a shared 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 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 is safe to say that there is currently a huge selection of hygrometers. Some air humidity sensors are only suitable for industrial use, while others are only suitable for domestic use. So, prices for the simplest household appliances start at 4 thousand rubles. For this money, you should not count on high-precision hygrometers. As a rule, these are the simplest capacitive sensors with a service life of no more than 10 thousand hours.

Models of the middle price range, such as Elicent ELEGANCE, will cost about 8-10 thousand rubles. In return, you will receive a unit with a service life of approximately 30,000 hours.

Sensors with fans of the high price range costing about 20-30 thousand rubles are exclusive solutions that fit any room design. In addition, these 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 supply ventilation. To do this, you can make a grill in the door leaf, which will be quite enough. In order not to get sick, you can change the circuit 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, 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 a humidity sensor is. The price of such equipment may vary depending on the power, functionality, dimensions and other parameters. Such a purchase is not cheap, so first evaluate how much you need the described device. If fungus has begun to appear in the bathroom or bathroom due to increased moisture and conventional ventilation does not help, a hygrometer mounted on a fan will be very useful. In some cases, the problem is solved by an electrically driven fan that must be turned on and off manually. It's much cheaper and almost as good.