How to connect a fan with a humidity sensor: subtleties of connection and installation + selection rules

Inclusion in the circuit of an external sensor

In any of the above schemes, you can include an additional sensor for humidity, air pollution, a timer (if there are no built-in ones), a motion or door opening sensor.

The most effective ventilation will be in the bathroom, controlled by a humidity sensor, and in the toilet - by a timer or an air pollution sensor.

Additional sensors are connected to the phase wire - the same one that coming from the switch, in a single line. Sometimes you need to connect and zero to the device

It is worth noting that external sensors are usually much less durable and reliable in the bathroom than those built into the fan.

SELECTING A BATHROOM EXHAUST FAN

To choose the right fan for the bathroom, you need to know and take into account their main characteristics, which include:

1. Performance

This parameter shows the amount of air (measured in cubic meters) passed by the fan per hour. To correctly calculate the required performance of a bathroom fan, it is enough to multiply the free volume of the room (in cubic meters) by 10. Most often, the standard performance for such fans is 95-100 cubic meters / h.

2. Noise level The level of noise that comes from the fan during its operation is a very important characteristic.

I strongly recommend that you pay special attention to this parameter when choosing. Manufacturers, most often, produce universal devices, the main technical characteristics of which are suitable for most use cases in a standard apartment. But at the same time, the level of noise generated by fans can vary greatly, and this is the main indicator on which your comfort depends during operation. leave it. It is better to choose a fan with a noise level of 26 dB (decibel) or less

Remember, every 3 dB difference in noise figures is roughly equal to a TWICE increase in noise intensity!

But at the same time, the level of noise generated by fans can vary greatly, and this is the main indicator on which your comfort depends during operation. leave it. It is better to choose a fan with a noise level of 26 dB (decibel) or less. Remember, every 3 dB difference in noise figures is roughly equal to a TWICE increase in noise intensity!

3. Security

The exhaust fan, like any electrical equipment, corresponds to a certain degree of protection. We already wrote more about the degree of protection in the article "Parameters, as well as the main characteristics of electrical equipment." For bathrooms, the fan protection degree index must not be lower than ip44.4. Power consumptionThe electrical power consumption of the fan, measured in Watts. Depending on this characteristic: the choice of materials (cable type, section, etc.), the connection method and some other electrical wiring parameters. Most often, household exhaust fans for bathrooms are unpretentious and have a relatively low power consumption, do not require any special, unusual solutions.5. dimensions

All axial exhaust fans are standardized, there are several basic sizes. For the right choice, you need to know the size of your bathroom vent, where the fan is supposed to be installed.In addition to these, there are other characteristics, such as the frequency and speed of rotation of the blades, the mass of the fan, the total pressure created, etc., but they are not so important, and when choosing, it is enough to be guided by the list of parameters presented by us above.

It is also good to understand the main types and varieties of exhaust fans for bathrooms.

Scope of application

Wiring diagram for a fan with a humidity sensor

The installation of an exhaust device is relevant in any room with high humidity or periodically appearing dampness, starting with residential facilities and ending with outbuildings.

1. In the cooking area, in the kitchen, the installation is determined by the specifics of the room. The air is highly humidified during cooking, in addition, odors spread around the room.
2. Installation of ventilation in toilets and bathrooms is mandatory. According to the regulations, the change of air in them should occur every 10 minutes, which cannot be achieved with a natural inflow.
3. Most often, the cellar is the wettest room in the house. Installing an extractor hood in the basement wall will help rid it of the musty smell of dampness.
4. The pool, as well as the bath, requires the installation of special devices. Their absence can lead to the formation of fungus and the rapid destruction of the structure.
5. Another place suffering from excessive moisture is the attic. To dry it, it is enough to put a fan with a humidity sensor.

A high-quality fan is designed for a long service life. These products are purchased infrequently.

Therefore, it is better to give preference to devices with a large number of options.

Installing a fan in a ventilation duct

Before finally mounting the device in its place in the ventilation duct, it is important to make sure that all the necessary wires are connected. Most often, the cable is laid in the wall directly from the junction box.

When connecting, it is important to match the phase on the terminal and on the wire. If a duct fan with a timer is installed, then it is necessary to connect a third, signal, wire

For installation, it is necessary to dismantle the decorative panel covering the air duct. If you intend to fix the device with self-tapping screws, you must first drill holes in the wall for the dowels.

Then you should hammer the dowels into the wall, install the device and at the end screw the screws into the place prepared for them. The second option for attaching the device is using a special glue or sealant.

The mount is not as reliable, but it is simpler.

Types of household fans

The equipment is produced in two varieties: built-in and separately located. The most common turn on is by pressing the switch. Automatic electrical appliances are equipped with electronics that simplify and control the work.

Additional features are:

• on/off timer;
• illumination of different colors;
• humidity sensor.

The device turns on when the permissible humidity level is exceeded and turns off when this value returns to normal. By design, there are radial (centrifugal) and axial hoods, ceiling and wall hoods, with and without blades.

Exhaust equipment requirements in the bathroom

In accordance with regulatory documents, in order to create normal air exchange, you must adhere to the following indicators:

• 8-10 sqm/h for 1 cu. for a combined bathroom;
• 6-8 sqm/h - For bathroom.

The volume of exhaust air from these rooms is more than 30 cubic meters per hour. The permissible norm is 30 dB - if it is higher, then for people this sound will be too loud and annoying.

Performance calculation by formula

Before buying equipment that is optimal in terms of productivity, calculations are necessary. First you need to calculate the volume of the room (height multiplied by area), which is multiplied by the aeration rate.

Example: a room has an area of ​​8 m3, a height of 2.5 m. It turns out a volume of 20 m3. The resulting number is multiplied by 6 ... 8, it turns out 120 ... 160 m3 / h. Therefore, for a room of 8 m3, equipment with a capacity of 120 ... 160 m3 / h is required.

Modern additional devices

Modern additional functions increase the power of the hood. The maximum increase is 10%. The most popular electrical appliances that operate economically and silently - their power varies from 7 to 18 watts. If the power indicator is too high, then a draft and noise of the air flow is created.

Location of ventilation ducts

It is easy to install the unit if the shaft is located directly behind the bathroom wall, even if it is combined with a toilet or located next to the kitchen. If these two rooms are separated, then a channel structure is required. It is installed on the shaft segment, at the junction of 2 air ducts.

Designs and principle of operation

Depending on the expected tasks and operating conditions, it may be necessary to select a fan model of a certain design.Classification of exhaust fans for rooms is carried out according to the principle of operation and installation option. In accordance with the task, you can choose a device of one of two types:

1. Axial fan. The most famous variety, which has the simplest design. The movement of air masses is carried out using an impeller, on which the blades are installed at an angle. Blades rotating in a cylindrical housing capture air and push it in an axial direction. This method is characterized by high performance, since it allows you to distill significant volumes of air in a short period of time. The main disadvantage of this design is the inability to cope with large aerodynamic loads. Axial models can only work effectively in conjunction with large diameter air ducts that are not contaminated with a significant amount of waste. If the building is high, then on the lower floors, devices of this design may not be able to cope with the tasks.
2. Centrifugal fan. It has a more complex design, which was previously found only as part of industrial ventilation systems. The body of the device is made in the form of a spiral casing. Inside, a wheel with blades fixed on a cylindrical surface is mounted on the shaft. The shape of the casing is of key importance in the operation of the device. During operation, the air is captured by the blades and begins to move from the axis of rotation to the periphery. At the same time, there is an increase in pressure as a result of compression of the air mixture. Under the action of rotation and centrifugal forces, compressed air moves along the spiral casing and is ejected into the outlet connected to the ventilation duct.This principle of the device cannot provide high performance, but it creates an acceptable pressure that allows you to push the exhaust air even into a narrow and polluted duct. Devices of this type are recommended for installation on the lower floors of buildings.

There are also less significant differences in the design of the devices. In centrifugal fans, the blades can be inclined both in the direction of rotation of the impeller and against it. Backward-facing blades will save energy. Forward-curved blades provide more pressure, thereby increasing work efficiency. If there is no need to save electricity, for the same performance, a model with forward inclined blades can have a smaller wheel diameter or a lower rotation speed. In this way, the noise level can be reduced.

We recommend you to read: Plastic gratings for ventilation

Of fundamental importance is the configuration of the device, which is selected in accordance with the intended installation method. Fans of both principles of operation can have two versions:

1. For outdoor installation. This is the most commonly used variety. The device is placed in the duct opening. Outside, the mechanism is closed with a decorative grille. The main disadvantage of this method of placement is the increased noise level during operation.
2. Channel. The design involves placement inside the ventilation duct. The farther the unit is from the ventilation grille, the lower the noise in the room.This feature allows you to install devices with higher power without fear of excessively loud noise. The disadvantage of this type of devices is the increased complexity of installation. Sometimes the shape and configuration of the ducts do not allow the installation of duct models.

Criterias of choice

The most effective way to get proper ventilation is to purchase and install a forced-type electric fan. Usually, for such purposes, wall-mounted axial fans of various capacities are purchased.

Wall-mounted axial fan for forced air supply

When choosing such a device, you need to pay attention to:

• Security system. The fan is a household appliance, and the bathroom is a closed room with a high degree of humidity, so the device must have the maximum degree of protection against water and steam ingress.
• Noise isolation. The noise level of the device should be kept to a minimum so as not to annoy people living in the apartment. If necessary, you can install a special silencer and supplement it with soundproofing materials that fit inside the fan.
• The power of the ventilation device must correspond to the dimensions of the bathroom and the number of residents. With insufficient power, the meaning of this system will simply be lost, since it will not be able to fully perform its functions.

Requirements for forced fans

• The noise level in a small room should be no more than 35 - 40 dB.
• The ventilation system must create a regular air change at least 5–8 times per hour and comply with SNiP standards.
• The exhaust device must have a check valve if the air is to be discharged through only one veterinary duct.
• The enclosure must be at least waterproof to IP34.
• A 36 V motor will allow the device to work quite silently.

Installing a fan in the duct

Silent duct fans are easy to install. Products of this type are mounted in several local ventilation systems, and not in one centralized branched ventilation duct.

In this case, the length of the air ducts is reduced and the financial costs for installing the ventilation system are reduced.

Similar models are installed:

• in the rupture of the ventilation pipe;
• at the beginning of the ventilation system, if the device works for inflow;
• at the end of the ventilation duct to ensure the removal of air.

Devices are installed on straight sections of the channel. At the same time, additional elements of the ventilation system (filters, distributors, etc.) are not installed in such places.

In order for a fan to be connected to a duct, they must match each other in equivalent diameter.

Its value is found by the following formula:

D=√4HB, where H is the height, B is the width of the ventilation pipe.

The distance from the fan inlet to the duct turn must not be less than the equivalent diameter of the device, and from the outlet to the next turn - at least three diameters. In this case, there are no aerodynamic losses in the pipe, and the ventilation system works normally.

During the installation, they first read the instructions for using the duct ventilation device - study installation features and operating rules. If the product cannot be installed independently, then it is better to contact an experienced craftsman.

When mounting small models do not use fasteners. Large ventilation devices that are installed in industrial enterprises are attached to the duct using several hangers, supports and brackets.

The main thing in installation is to ensure a strong connection of all parts. For noise insulation, separate silencers are installed at the inlet and outlet of the ventilation device.

Duct fans work in any position!

During the installation of these devices, perform the following steps:

• in front of the ventilation device, an air duct with a minimum length of 1.5 m is mounted;
• flanges with a diameter of more than 400 mm are fixed to the duct with bolts and special brackets;
• the ventilation device is fixed on steel brackets or separate suspensions;
• leave free space near the device for future maintenance work;
• duct ventilation, which is mounted in the kitchen, is installed with a bell (funnel) up.

Docking of the air duct with the ventilation device is carried out using special clamps. To output the electrical cable in such a situation, a cable channel is used.

Fan with built-in humidity sensor

There are 2 ways to connect appliances equipped with a humidity sensor. One of them is designed for automatic operation.

• Zero is applied to the N terminal.
• On L - phase.
• The fan is connected both through the switch and directly.

The appliance will operate continuously if the humidity in the room remains above 60%. If it drops to 50%, the device turns off. In this mode, the timer is not activated.

The second version of the connection scheme implies an extended mode of operation.As in and in the previous version, a phase is applied to L, and zero to N. A jumper is installed between terminal 1 and L, on which the switch is mounted.

When the circuit is closed, the device turns on and works for a certain time, provided that the humidity is below 50%. If it is higher, the device will continue to work until the moisture level drops to normal levels. Only then does the timer start.

What is a humidity sensor fan

Installation example for a fan with a humidity sensor

The main function of exhaust fans is to circulate and remove moist air from unventilated areas.

The main parts are an aerodynamic impeller, an engine and a special valve that stops back draft.

The design is mainly enclosed in a plastic case, but there are options with an iron frame.

Conventional exhaust fans and those with a humidity sensor have an operating principle based on the laws of aerodynamics.

Compact size, light weight and design features of the device allow installation not only on the wall, but also on the ceiling.

Features of ventilation installation

If for some reason there is no ventilation in the bathroom, it is not so difficult to create the necessary system.

Apartment buildings are usually designed in such a way that the ventilation duct is located directly behind the wall of the bathroom or toilet. It remains only to carefully make a hole in the right place (if there is none) so that it goes into this channel.

A radial axial fan is installed inside the opening.The device is connected to the power supply, observing all the requirements for the operation of electrical appliances in rooms with high humidity.

If necessary, mount additional controls (timer, gyroscope, etc.). The niche is closed with a beautiful decorative lattice.

If the apartment has a separate bathroom, and the ventilation duct is located outside the walls of both rooms, the second fan is installed in the same way as described above.

Otherwise, a vent is made in the wall separating the toilet and bathroom. A fan is also placed in this opening and covered with decorative screens on both sides.

Sometimes it is more convenient to use decorative grilles, in which the design provides for mounting the fan in special slots.

The figure clearly shows the connection diagram of the exhaust fan to the power supply using an timer, which allows you to turn off the fan some time after the visitor leaves the bathroom

It is somewhat more difficult to solve the problem of ventilating a bathroom when the ventilation duct borders on another room. In this case, you will have to create duct ventilation.

First you need to choose a place for the vent in the bathroom and toilet. Then it is necessary to draw up a plan for the placement of the ventilation duct, along which the air masses will move out.

When creating duct ventilation in the bathroom, a flexible corrugated box is used only in small areas where the installation of other structures is impossible or difficult

There are the following types of ventilation ducts:

• plastic round or rectangular section;
• hard or soft corrugated metal;
• metal, tin or galvanized, usually rectangular.

Plastic boxes are easier to install and lighter in weight than metal structures, while they are durable and easy to care for.

Therefore, plastic structures are confidently replacing metal from the construction market. Corrugated products are used extremely rarely, they are valid only for short distances and are used only in particularly difficult cases.

It is recommended to install the box even during the repair work in the house or even before they begin, however, the installation of the fan and decorative grilles is carried out after finishing work is completed.

After the installation of the ventilation system is completed, it is necessary to check the operation of the equipment.

To create duct ventilation in the bathroom, metal or plastic boxes of rectangular or round section should be used.

Mounting the switch for the hood

Depending on the design of the chosen model, a cable is laid, consisting of two or three cores. At one end it is connected to the junction box, and the other must be connected to the switch.

The choice of cable for the fan depends on the type of switch that is planned to be installed.

Before connecting the wire directly to the switch, it is necessary to dismantle all the keys from the latter.

If a single-gang switch is used, two wires are required. The two-button switch is already equipped with three terminals. One of them is connected to lighting fixtures installed in the room.

A two-gang switch allows you to implement a circuit for autonomous operation of the fan.

If the walls in the building are made of drywall, then the cable should be placed in a special corrugated pipe.

The wire must not be installed. The stock is made from two sides: in the socket box of the switch itself and in the free space of the junction box.

A reserve of cable is necessary in case of connecting additional cores or any other manipulations later.

Conclusions and useful video on the topic

Video instruction for installation of the simplest model:

Detailed instructions for installing a hood with a check valve in a private house:

Silent 100 manufacturer's instructions:

Installing the switch for the fan:

As you can see, you can set up exhaust ventilation yourself, without involving professional electricians, but subject to several conditions. To connect a fan (simple, with a timer or a switch), you need to understand the electrical circuits, carefully study the design of the device and take into account technical and sanitary standards during installation.

During the study of the material, there were questions about connecting an exhaust fan in the bathroom? Or can you give valuable advice to those who are faced with a similar task for the first time? Please leave your comments in the box below.