Design and design features of silent fans for kitchen hoods

Indispensable for organizing high-quality and most efficient air exchange in a residential, industrial or commercial building, the exhaust fan is characterized by increased performance and optimal power. Regardless of the chosen model, a household fan must meet a set of requirements and its selection takes into account such characteristics as the intended purpose of the room, its volume and the number of people present.

In the absence of a natural flow of fresh air, household fans for homes and rooms such as bathrooms or toilets guarantee their high-quality and timely ventilation. A built-in and independently installed fan in the hood guarantees the cleaning of functional rooms or individual zones by removing the contaminated gas-air mixture into a window or natural ventilation system.

In private houses, the exhaust fan is installed on the roof

Importance of use and intended purpose of devices

A functional fan for ventilation can be installed independently or by involving experienced and qualified specialists in the work, but it is necessary to choose the right fan for exhaust ventilation. As a high-quality and productive device, an exhaust fan must be installed in certain rooms, which allows you to comply with sanitary and hygienic standards:

• a high-temperature exhaust fan is mounted above the hob or stove, which guarantees the maintenance of an optimal microclimate in the kitchen;
• a duct fan is installed in a bathroom or toilet, combined bathroom and provides regular and timely air exchange in functional rooms;
• a household exhaust fan is suitable for arranging a common corridor or vestibule, effectively removing the contaminated gas-air mixture outside the home;
• a fan for ventilation in a bathhouse or sauna guarantees a reduction in the level of precipitated condensate and overheating of air masses, which is important for maintaining people’s health.

Powerful fans for ventilation of premises are widely used to organize the air exchange process in houses and apartments, which is due to the complex of their operational advantages and parameters. When choosing a fan for the hood on your own, the homeowner should understand in advance the principle of operation of the device, then the ventilation will work as efficiently as possible and ensure comfort in the house.

Installation and connection rules

Duct-type axial fans are installed in the air duct distribution of the system, as an intermediate element between pipe sections. Therefore, manufacturers make the device itself from three parts, connected to each other with plastic clamps. The middle part is a fan, the two outer parts are diffusers and, in combination, connecting couplings with air ducts.

To install a fan in a pipe system, you need to make a break in the air duct at the installation site to the length of the device itself. The fan is disassembled, diffusers are installed, which are attached to the air duct system in the standard way: either with sealed clamps or double-sided couplings with rubber cuffs inside. Then the device is mounted between the diffusers.

Duct fan installation

As for connecting to a 220-volt AC network, this is either a socket or a circuit breaker in the distribution board. The main thing is to connect the fan to the wires correctly. There is no power supply in it, there is a terminal box with two or three contacts. If there are two, then the wires are connected to them.

Read also: A variety of grease filters for kitchen hoods

If there are three contacts, this means that the fan has two shaft rotation speeds, respectively, and the impeller blades. One wire is connected to the “N” terminal, this is the neutral or zero phase. The second connects to one of two wires, which are designated L1 or L2. One of the contacts is the maximum rotation, the second is the minimum (60% of the nominal). Now you need to decide which contact to connect the power wire to.

A silent duct fan installed in the wall is mounted in the following sequence:

• A ventilation system is assembled on site with a fan installed in it. In other words, a device is mounted in the pipe, which is attached inside to the walls of the air duct with rubber inserts.
• This pipe is installed in a channel made in the wall. The connection wires are led indoors.
• A check valve is attached to the outside, and a decorative grille to the inside.
• The unit is connected to an outlet or through a long wire to contacts in the nearest junction box.

General characteristics and design features

In appearance, the hood fan is a compact device with several blades; their rotation ensures the distillation of air through the outlet channels with its forced intake from the outside. Practical and high-quality fans for room ventilation, due to their operation, do not disturb the process of natural air exchange, increasing the efficiency of the ventilation system.

As a rule, all exhaust fans operate from the mains

Purpose of the device

Electric and mechanical axial fans (or other types) must be installed in a certain location where there are frequent crowds of people, concentrated unpleasant odors and smoke, and high humidity. If the device for ventilation of the room is selected or installed incorrectly, moisture will accumulate in it and the microclimate will change, which leads to the proliferation of mold, microorganisms and pathogenic bacteria.

Heated and dry air removed from the room after the exhaust fan is connected contributes to the development of all kinds of respiratory diseases, which negatively affects people's health. An attractive design exhaust fan with shutters fits perfectly into the interior design of your home and will complement the concept of its stylistic design, combining with other furnishing elements.

What to consider when purchasing a hood fan?

Even before making a final decision in favor of one or another model of exhaust device, which will have to support the forced movement of air flows in the room, you should very carefully study its following characteristics .
Performance. Any buyer can calculate this parameter, even without special knowledge. All you need to do for this is to multiply the volume of the room by the air exchange rate. The last parameter refers to the number of air changes per 1 hour of operation. In this case, the multiplicity depends on the type of room for which the exhaust device is purchased. So, for a bathroom used by up to 3 people, it will be equal to 6, if there are more than 3 users - 8 and up to 10 for a toilet.

When choosing a silent fan model for an extractor hood, it is advisable to buy a device that has inflated performance. So, for a bathroom, a device with an indicator of 95-100 m3/h is best suited.

The level of noise created during operation of the device. The operation of a fan is inevitably accompanied by noise - mechanical and aerodynamic. Under the first there is noise that arises as a result of the operation of the engine, or, more precisely, vibration transmitted to the air duct. Aerodynamic is the noise that arises from the movement of air currents. To prevent a duct fan from creating inconvenience for you, choose models with noise levels of no more than 25 dB. Models with a threshold of more than 35 dB will not allow you to stay indoors for a long time without feeling discomfort. Therefore, it is not recommended to purchase devices with similar characteristics for residential premises.

There is a solution to reduce the noise level of a duct fan. This can be done by installing a muffler behind the housing, as well as by additionally finishing the ventilation shaft with a material that has enhanced sound insulation characteristics.

Design safety. This parameter indicates the level of protection of the device from moisture and dust. It is necessary to take this into account if you are looking for a duct fan model that you are going to install in a rectangular shaft in the bathroom or kitchen, where high humidity is constantly present. If moisture gets inside the housing, a short circuit may occur. Therefore, it makes sense to immediately buy fans equipped with moisture protection for such rooms. As an alternative, you can purchase devices that can operate in low voltage 24V conditions.

Hood functionality . Today in stores you can find 100 mm models that can operate in two modes - automatic or standard. Standard axial supply fans start working the moment the lights in the room are turned on. This is an excellent solution for rooms where the humidity level is normal. If the humidity in the room is constantly increased, then it will be difficult for such devices to remove air. In this case, it is best to purchase a model with a timer that will automatically turn the device on and off.

Also, some fan models can be equipped with a special humidity sensor, which is very convenient for the bathroom. Of course, such hood devices will cost more than standard ones. But thanks to the use of such additions in them, they will be able to remove excess moisture from the room much better and faster.

Quality of the device . If you want a bathroom or toilet fan to serve you for many years without requiring attention to operation and repair, then choose models that meet international standards. For example, make sure that the duct fan has a protection class of at least IP 34.

Don't skimp on buying a fan for your home. Try to purchase models that are produced by well-known companies and are very popular among consumers.

Choosing an installation location

When choosing the right exhaust fans for rooms, it is important to carry out a preliminary design of the air exchange system and calculate its productivity, which will make the installation of the exhaust fan correct:

• an exhaust fan with blinds, as well as a surface-mounted fan, are installed on the walls, with the natural air exchange system operating in every house being diverted into the ventilation duct;
• roof exhaust fans cut into the roof and are used to arrange a ventilation system through the technical or attic floor for optimal ventilation;
• a ceiling fan is used when arranging rooms in a private house and other purpose-built buildings, which guarantees an optimal level of maintaining a comfortable microclimate;
• household duct appliances and fixtures are designed for installation in a ventilation duct; a high-performance duct fan facilitates efficient removal of air into the duct;
• an overhead vent fan is used to decorate a window opening; such devices do not have increased power, but are characterized by practicality;
• A built-in exhaust fan is part of the exhaust equipment offered by manufacturers in a wide variety and is necessary for kitchens, baths, and lavatories.

Modern exhaust fans can be equipped with a control panel, regulating the power.
Modern powerful exhaust fans are used to enhance the functionality of the general ventilation system and allow you to maintain an optimal microclimate, temperature and humidity in the living room.

Features and characteristics of the equipment

Silent duct fans on the market are traditionally divided into different categories and subtypes. But a healthy microclimate largely depends on performance characteristics. One of which, noiselessness, is even included in the name, that is, the buyer always needs to make a choice by determining a number of parameters.

The main ones are:

• noiselessness;
• performance.

If you like silence, then you need to start your search with the first characteristic, since it is this that has a significant impact on the comfort of your stay.

Device noise criterion

According to sanitary standards SN 2.2.4/2.1.8.562-96 , in residential premises and a number of others, the noise level should not exceed a moderate 30 dB during the daytime and 20 dB at night. Which are comparable to a quiet whisper and in many situations will be quite appropriate for kitchens, bathrooms and other rooms.

Every duct fan on which a set of special work has been performed is silent. These include isolating structural elements from each other, for example, the engine from the body, as well as optimizing the aerodynamics of the blades, the channel through which contaminated air masses move

But you still need to remember that often the sound produced by these fans at 30-35 dB, even from a distance of several meters, will irritate users. This is especially true for situations where there is a bedroom or children's room next to a toilet or bathroom equipped with ventilation equipment.

As a result, you should know that truly silent, and without any compromises or marketing tricks, are considered models whose performance characteristics do not exceed 25 dB. In this case, the sound of the fan running is comparable to a very quiet whisper.

Since the good is always the enemy of the best, when purchasing you need to remember that models that fall into the category of market leaders in terms of noiselessness emit no more than 20-22 dB.

And although the advantage over conventional low-noise models may seem insignificant, it may well become decisive after several years of operation. Those. when the performance characteristics of the device decrease, the bearings begin to wear out, the air channels become clogged with dust, and the anti-noise gaskets wear out.

All silent units of the presented type are suitable for use anywhere in the channel, which makes them universal and effective in any conditions

A number of complex solutions from engineers can provide a comfortable sound of operating ventilation equipment.

These include the following:

• the use of high-precision bearings - such high-quality and balanced products eliminate beating, as a result of which there will be no vibration, which, when resonating, can significantly enhance the sound;
• high manufacturability of the blades - one of the reasons for noise is the aerodynamic component, therefore, developers, wanting to make the sound comfortable, carefully select the number of blades, optimal angles of inclination, and also carry out precise balancing of the impeller elements during manufacturing;
• the use of technological housings - high-quality manufacturing materials (metal, plastic) eliminates vibration of individual parts and assemblies, aerodynamic noise of moving air;
• using vibration-damping gaskets - quiet operation is also achieved by using special types of rubber as gaskets to eliminate contact between the housing itself and the attachment points of the electric motor to it.

Gaskets have become an important design element; they insulate the fan housing from the air duct and wall.

Bearings, blades and special housings and gaskets - all this reduces vibration, turbulence of air flows and their resonance to insignificant values.

An important point is that a set of works to reduce noise makes fans for various hoods more reliable and durable

Today it is no longer uncommon to decorate ventilation shafts with modern soundproofing materials. Reduces noise and securely mounts the electric motor to the housing. The power plants themselves are common and are used on all types of fans.

Fan Performance Indicators

This characteristic is considered one of the most important, as it is interconnected with noise. It is clear that the higher the performance, the louder the electric motor and accompanying sounds sound.

As a result, you should not thoughtlessly buy an exhaust fan for the bathroom, kitchen, or toilet according to the principle “you can’t spoil the porridge with oil,” as this can result in a decrease in living comfort and financial losses.

But it is not difficult to avoid negative consequences. That is, the optimal power can be calculated, knowing that such an indicator must correspond to the derivative of the volume of the room and the air exchange rate.

For example, the volume of a shower room is 5 m³, and the recommended air exchange rate, according to SNiP, is 7-9. And to calculate productivity, you just need to multiply cubic meters by any multiple number. The result will be 35-45 m³/hour.

Being the most important characteristic of all kinds of duct fans, performance must be calculated correctly, since an attempt to achieve silence due to lack of power will lead to the need to buy a new unit. And excess power leads to excessive energy consumption, drafts and increased operating volume

Different types of fans provide a number of important options. Therefore, so that during operation you do not have problems with the device, you should pay attention to a number of characteristics when purchasing.

Which, in any situation, include:

• design safety;
• functionality;
• geometric dimensions;
• price.

Although all of the listed features are traditionally in the shadow of the main performance characteristics (performance, noise), they cannot be called secondary. Since each of them significantly affects the characteristics of ventilation equipment.

Types of exhaust fans offered on the market

In order to correctly and correctly select a powerful fan for exhaust or arranging an effective and efficient air exchange complex, it is important to ensure that the parameters of the main ventilation fans are taken into account. When choosing an exhaust wall, ceiling or other type of device, it is necessary to take into account additional functional and operational parameters of the devices, determined by their technical characteristics and division into types:

• exhaust industrial models are used for the arrangement of large and large-scale premises for special purposes, such as warehouses and office buildings, garages and other buildings;
• axial fans for exhaust hoods, which are a structure with an axle and blades attached to it, rotating under the influence of a connected electric drive;
• a centrifugal fan, its body resembles a snail in appearance, and the rotation of the internal blades is ensured by the use of the physical principle and centrifugal force;
• a reversible fan used both for supply ventilation and in the design of forced ventilation, which makes it a universal and productive device.

To arrange supply ventilation, household exhaust models can be used; by connecting fans in series, a supply and exhaust air exchange system is installed.

Types of duct fans

Basically, silent hoods for the kitchen or bathroom are divided into two categories:

• according to form,
• by design.

In the first case, there are two groups: with a round cross-section of the body and with a rectangular one. In the second, these are axial fans, radial and centrifugal. Duct fans for round air ducts are most often used in private housing construction. But there is one point that determines the installation location.

For example, very often the exhaust section of a ventilation system is a vertical pipe (usually plastic or concrete) that penetrates the building from the basement to the roof. Such an air duct is hidden in the walls during the construction process or constructed in the form of a separate box. You cannot install a duct fan in it. Because if the device fails, it will be impossible to repair or replace it. A rooftop model can be installed on such an air duct. Ducted devices are installed in air ducts that remain outside the building structures. For example, collected in the attic.

As for rectangular units, they can be classified as industrial exhaust fans. But this does not mean that they are not used in residential construction. Rectangular ducts are also used in residential or office buildings. The photo below shows one of the models made of plastic. This is a wall-mounted or ceiling-mounted device with a rectangular body. Pay attention to its blades; this is a centrifugal fan. Its blades are located along the direction of air flow.

Rectangular centrifugal fan

The concept of choosing a household device: what is important to consider

The conceptual choice of a device requires obtaining a full and informative consultation from experienced specialists; they will help you choose a powerful exhaust fan. It is also recommended to trust the installation and installation of an exhaust fan to professionals; they will use a special calculator to calculate the performance and quality, air exchange rate in a house or apartment.

An exhaust fan can be stylish

It is impossible to install forced ventilation without studying information on how to choose a fan for an exhaust hood, because centrifugal exhaust fans and exhaust fans with additional functionality have their own characteristics. Based on technical parameters and operational characteristics, you can easily and simply select a fan for subsequent installation, if necessary, to arrange supply and exhaust or supply ventilation.

Device power

Depending on the operating mode, you can select the power of the device and then the radial exhaust fan or centrifugal fan will operate in optimal mode. The calculated power parameter is used when arranging any premises; to check their operating conditions, the master may need instruments to measure the parameters and power indicators of the selected model.

Ceiling-mounted exhaust devices are usually more powerful than wall-mounted ones

Duct fans for hoods: types and features

Today there is a wide variety of models of such devices on the market, which may differ from each other in different parameters. So, today there are quite a lot of duct fans produced with different housing shapes:

• Round. They are designed for installation in round ventilation ducts. This is by far the most common option that can be used in the kitchen or bathroom.
• Rectangular. They are mounted in ventilation shafts having a square or rectangular cross-section. Most often, industrial fans have this form, characterized by increased operating power.
• Square. They are very similar to rectangular axial exhaust fans. They are mounted in air duct shafts of a square configuration. Their main distinguishing feature is increased power. They are often purchased for industrial use.

Duct fans for exhaust hoods can also be classified depending on their design.

Axial

The main distinguishing feature of these models is the cylindrical housing, where a fan with blades mounted on the axis of the electric motor is installed. With this design, air flows move parallel to the axis of the device. At the same time, there is often an additional special collector at the inlet, which increases the aerodynamic performance of the fan. Compared to other models, axial fans for exhaust hoods are characterized by high efficiency, which is more than 100 cubic meters of air per hour.

Axial models also attract attention due to their ease of installation. Therefore, they can often be found in bathrooms and kitchens. But they also have disadvantages . They have very low pressure characteristics, and during operation they create a lot of noise, the level of which can reach 30-50 dB.

Radial

The design of these devices uses a spiral-shaped housing where a paddle wheel is installed. During its rotation, air flows begin to move in a radial plane, while centrifugal force forces the air to compress and leave the device body. Radial fan blades can move both backwards and forwards.
When the first mode is activated, up to 20% of electricity is saved and at the same time the noise level during operation is significantly reduced. Models with a diameter of 100 mm, which have forward-curved blades, seem to be quite practical, since they increase the power of the device. All radial fans are relatively compact devices, which allows them to be installed in an air duct of any shape without much difficulty.

Centrifugal

Models of this type appeared on the market relatively recently, but have already gained popularity among consumers. Such devices are ideal for rooms larger than 15 square meters. m. High power and almost complete silence during operation allow them to effectively cope with the assigned task. One of the advantages of centrifugal exhaust duct fans is the possibility of installation both in front of the air intake and directly in the center of the ventilation shaft.

Switching method

In modern housing, it is recommended to use current technologies, and the choice of fans for an apartment is made on the basis of their additional capabilities; axial fans for exhaust hoods can be turned on and off themselves. A practical centrifugal fan with adjustable power, speed and switch, allows you to automate partially or completely air exchange in the target room.

The choice of exhaust hoods with additional functionality and an already installed fan, kitchen hoods and other appliances not only for the kitchen, but also for other functional rooms, is important to do correctly. Based on the advice of experienced and well-trained specialists, it is very easy to choose an exhaust fan for arranging your home or its individual zones, guaranteeing the maintenance of an optimal microclimate in the room!

Main types of exhaust fans

I would like to start with the fact that all exhaust devices are divided into types - standard and automatic . However, the difference between such devices is that automatic hoods operate practically without human intervention.

• A simple standard exhaust system consists of an ordinary electric fan placed in a tubular housing. In this case, it is turned on thanks to a separately installed switch or a button built into the housing. Very often in practice, the hood is connected to the button for turning the lighting on and off in the room. However, this approach to the matter can hardly be called correct, since exhaust air will be removed only when a person is in the bathroom. But very often this time is not enough for the moisture from the room to completely evaporate. Therefore, it is important to install a separate switch for the fan.
• An automatic hood, unlike a conventional one, is distinguished by a built-in electronic unit that controls the operation of the fan. This ventilation system has several operating modes and is equipped with a timer. In more expensive models, sensors are installed to control the level of humidity in the room. If the moisture level exceeds the permissible parameters, the fan automatically turns on, and after the humidity normalizes, the device turns off.

In addition, both types of bathroom exhaust devices can be equipped with additional functions. Also, some models are equipped with a check valve that prevents air from the main air duct from entering the room. This is especially true in multi-storey buildings, in which not entirely pleasant odors from neighboring apartments can enter the bathroom.