Exhaust fan for a toilet: varieties, recommendations for selection and installation

Natural ventilation is traditionally used in apartment buildings. Air inflow is carried out through leaks in window openings, and removal - through ventilation ducts. Over time, ventilation becomes clogged, the installation of sealed windows makes it difficult to get air from the street. This leads to a decrease in the efficiency of air exchange. The problem can be solved by installing a fan in the toilet and other rooms with ventilation entrances.

Ventilation features

For a long time, the use of natural ventilation in residential buildings was considered quite justified. The main advantages of such a scheme are the simplicity of the device and the absence of energy consumption for the operation of the system.

Ventilation provides:

• inflow of fresh outdoor air;
• removal of carbon dioxide;
• removal of excess heat;
• decrease in humidity;
• removal of unpleasant odors and harmful gases.

The entrances to the ventilation ducts of residential apartments are usually located in the kitchen, toilet and bathroom, and this is no coincidence. In the kitchen, it is important to ensure the removal of gas combustion products during cooking; water and fat vapors are additionally eliminated. The toilet requires increased air exchange to maintain freshness. In the bathroom, you often have to deal with high humidity, from which ventilation saves. Living rooms are characterized by a cleaner atmosphere, so the air supply is provided from there.

Air intake from the street is carried out due to the difference in pressure outside the building and inside. Air exchange is greatly enhanced when ventilated. With the windows closed, air can only flow through the cracks. When using wooden window frames, the intake of air volumes from the street was sufficient.

Recently, sealed double-glazed windows with high-quality seals have become widespread. They significantly complicate the work of natural ventilation. Advanced window models to solve this problem are equipped with ventilation valves that allow, without opening the sash, to supply the room with fresh air in volumes sufficient for operation ventilation. However, such valves significantly affect the cost of windows and are not yet widely used.

It should be noted that the required air exchange is significant:

• When operating a four-burner gas stove. The air turnover must be at least 90 cubic meters. m per hour.
• For a combined bathroom. It requires air exchange of at least 50 cubic meters. m per hour.

The situation is complicated by the fact that during the entire life of the building, grease and other contaminants settle on the walls of the ventilation ducts. The ventilation should be cleaned by the building service provider. Residents of apartments are not allowed to carry out such cleaning on their own. Unfortunately, not all companies are conscientious about fulfilling their duties, so ventilation with very difficult air exhaust can often be found.

A forced exhaust ventilation device can partially solve the problem. The simplest device for mechanical air exchange is a fan. It is installed at the inlets of existing ventilation ducts for forced suction of air from the room.

Design options

Exhaust fans for toilets and other premises differ in their principle of operation and installation features. Depending on the operating conditions choose the optimal design:

1. An axial fan is the simplest and most common device. An impeller with blades located at an angle to the plane of rotation is located in the cylindrical casing. When switched on, the air is captured by the rotating blades and moves in the axial direction. The design shows high efficiency and is able to provide a large volume of air exchange in a short period of time. However, this is true only with low aerodynamic resistances of the ventilation ducts, that is, they must have a sufficient diameter and remain clean. On the lower floors of high-rise buildings, this type of device may not cope with its tasks.
2. A centrifugal fan is a more complex device previously used only in industrial ventilation systems. A wheel with blades is located in the spiral casing. During rotation, air entering the space between the blades moves radially from the center of the wheel to the periphery and is compressed. The centrifugal force throws the compressed air into the spiral casing, from where it is expelled into the ventilation duct. This design has a lower performance, but it successfully copes with dirty small diameter ducts, into which the axial fan is not able to push air. They are the only effective solution for installation on the lower floors of high apartment buildings.

Centrifugal fans can differ in the shape of the blades, which are bent forward or backward relative to the direction of rotation. Backward curved blades allow energy savings of up to 20%. With forward-curved blades, greater efficiency is achieved, so the impeller diameter can be reduced and the impeller speed can be reduced, resulting in lower noise levels.

Depending on the design of the inlets to the ventilation ducts, you can choose the fan with the most suitable mounting method. Both axial and centrifugal models are available in two types:

1. For outdoor installation - the most common. The device case is attached directly to the air vent. The mechanical part of the overhead fan is located in the ventilation pipe and is closed from the outside with a decorative overlay. Installation of the device is as simple as possible and does not require special skills, the installation process takes minimal time. The obvious disadvantage of this type of device is the increased noise during operation.
2. Ducted - built-in directly into the duct. These devices usually offer better performance. The location of the mechanism further from the ventilation grill reduces the noise generated during operation. However, the installation of models of such a design is more complicated and not always possible due to the peculiarities of the shape and location of the ventilation ducts.

Selection Tips

If the principle of operation of the fan and the method of its installation are determined, you can proceed to purchase. At this stage, it is important not to make a mistake in choosing a quality model with maximum reliability, efficiency and durability. To choose the best option, you should pay attention to the passport characteristics and product features.

Work performance

In general, the device for an hour of operation should provide a change of ten volumes of air in the room.

An exhaust fan for a toilet can also have low power, since the area is usually small. The bathroom may require slightly more performance. The most effective models should be purchased for the kitchen, especially if a gas stove is installed in it. This is due to the need to completely remove the combustion products of domestic gas.

Often in the passport of the device, not only the power consumption is indicated, but also the productivity in cubic meters of air, which are pumped over per hour of operation. Based on this value, it is easy to select the desired model. To do this, calculate the volume of the room by multiplying its length, width and height. The result is multiplied by the required air change rate, that is, by ten. The choice can be stopped on the model with the nearest higher performance.

Applicable materials

Most modern models are made of plastic. The use of durable polymeric materials allows to achieve long service life.

High-quality plastic retains its strength characteristics for a long time and successfully withstands shock loads.

Sometimes it can be difficult to distinguish between cheap materials of reduced strength. In this case, a close inspection of the surface of the parts can help. If there are no traces of poor-quality casting, raw seams and other defects, with a high degree of probability it can be argued that a high-quality polymer has been used. If not all surfaces have an ideal structure, it is possible that cheap plastic was used, which may be damaged soon after the start of operation.

Noise level

The noise generated by the device during operation does not affect the efficiency, but it can cause some inconvenience. It is not recommended to use devices generating more than 40 dB of noise.

However, the vast majority of modern models are characterized by quiet operation. The most expensive and high-quality fans can run almost silently.

If the rotating elements are not rigidly fixed to the motor shaft, they can be mounted on bushings or using bearings. Bushings not only increase noise, but are also more prone to wear and tear, which will significantly shorten the life of the appliance.

Degree of protection

Since the fan can be used in high humidity conditions, it is worth paying attention to the degree of protection. It is reflected in the IP marking, which is applied to the body of the product.

The marking consists of two numbers, the first of which shows protection against mechanical penetration, and the second - against moisture.

The dust protection of the fan may well be zero. Water resistance is much more important. A value of 4 is recommended to indicate protection against strong, directional splashes of water. However, for ceiling mounted fans, lower values ​​are also suitable.

Additional functions

Even budget models are quite effective in coping with their tasks. If funds permit, you can also purchase advanced designs equipped with additional functions:

• Check valve. In multi-storey buildings, there are cases of violation of traction in ventilation shafts. At the same time, air from the lower floors can get into the apartment. A check valve will help to avoid this trouble.
• Timer. In budget models, the device is turned on and off using a conventional switch. The timer allows you to set a delay in the automatic shutdown of the device after a certain period of time.
• Motion Sensor. The device turns on when you enter the room. Shutdown is usually done using a timer.
• Airing mode. The device can operate at minimum power for a long time, consuming less energy and maintaining a constant air exchange.
• Moisture sensor. The device can turn on automatically when the humidity in the room rises. This is especially convenient for bathrooms.

Installation process

In most cases, installing a fan hood in a toilet, kitchen or bathroom is fairly straightforward. The whole process consists of the following steps:

1. Electric cable laying. If the fan requires grounding, a three-wire cable is used. In other cases, a two-wire cable will suffice. The cable can be laid in a groove, corrugated tube or box.
2. Connecting contacts. The wiring is de-energized, after which the device is installed in a place prepared for it, all the necessary connections are made. If the fan does not have motion and humidity sensors, a separate switch is usually used. When the device is equipped with sensors, it must be constantly energized. In this case, the use of a separate switch is not necessary.
3. Securing the body. The overhead fan is attached to the wall surface using dowels and self-tapping screws. Channel models can be fixed with self-tapping screws or polymer glue.
4. Installing a decorative strip. If the fan has a removable grill that covers the air duct, at the final stage it is installed in its place.

The exhaust fan can significantly increase the efficiency of air exchange if it is difficult for one reason or another. It is recommended to choose quality models that will last for many years.

Additional functions will provide increased comfort during operation. Most devices are easy to install yourself. The use of forced ventilation can significantly improve the indoor climate.