How to choose and install a fan in the bathroom + how to connect a fan to a switch

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Tatyana Zakharova
Last update: March 2019

A forced ventilation device is one of the ways to ensure a comfortable microclimate in a private house or city apartment. More simple appliances - fans - eventually turned out to be squeezed out split-systems and air conditioners, however, they remained relevant in the bathroom or toilet.

Let's try together to figure out how to choose and install a fan in the bathroom for the most effective cleaning and removal of air.

Reasons for installing a domestic fan

The highest humidity level in the house is located in the bathroom or in the combined bathroom - where water is actively and in large quantities. The small size of the room, especially wall cladding, a sharp change in air temperature are additional factors in which high humidity becomes the most dangerous.

There is a risk of the spread of fungus and mold - unpleasant microorganisms that form colonies and are strong allergens.

Bathroom fan
Even if the bathroom has a large area and has a window (direct exit for natural ventilation), a device for extracting used air may be required in the winter, when it is risky to open the ventilation windows in the room during the adoption of water procedures

The appearance of black dots in the seams between the tiles or condensate not having time to dry on the mirrors, plumbing and pipes are the first signs that the natural ventilation system is broken. The reason may be a lack of fresh air through window openings (frames, transoms, special openings under the window).

In a private house, problems can arise due to the poorly thought out ventilation channels or supply valves in the walls.

The need for ventilation
Properly equipped ventilation is not only the protection of health from colds and allergies, but also the extension of the service life of electrical wiring, plumbing, furniture, wall decoration

The simplest solution to ensure forced circulation of air in the bathroom is to install a fan. Modern appliances have an attractive concise design and convenient controls, have a reduced noise level and performance sufficient to create a comfortable atmosphere. If there is experience in wiring, you can choose and install a fan yourself.

Criteria for choosing the right equipment

To buy a good fan, you can just visit the supermarket and find out all the secrets from the sales assistant. However, relying on honest and reliable information at 100% is not worth it, since one of the tasks of the seller is often the implementation of stale or most expensive goods. But it’s better to start by studying rating the best devices, after which you need to carefully study the important aspects of the upcoming purchase.

Types of household fans

Unlike production units, household appliances are small in size, have less power and look less industrial. Usually use stationary devices for exhaust ventilation, built into the wall or ceiling (mobile portable systems are used in construction sites, in workshops, etc.).

Fan Coverage Area
Bathroom appliances have a small coverage area. It is slightly larger than that of point-type equipment (for example, cooker hoods located above the stove), and much smaller than that of general exchange systems for servicing workshops, hangars, pools, etc.

According to the method of air intake and design, domestic fans are divided into two types:

  • axial, located in a cylindrical body and equipped with blades that capture and move air parallel to the axis;
  • radial, used to change the direction of the air flow from the axial version to radial when passing through the impeller of the device.

The first type is in demand much more often because of the simplicity of design and installation in a residential environment.

According to the place and method of installation, two groups are also distinguished:

  • waybillshaving a square or round shape, mounted in the ventilation duct hole (usually on the wall under the ceiling);
  • channelmore powerful and quiet, which are placed inside the ducts.

For a city apartment, only the first category is suitable, and for private houses there are options.

Channel fan circuit diagram
Designs of duct fans: on the left is a conventional type of device, on the right is a device with compression of the flow, the distinguishing feature of which is the presence of an impeller

Often, when choosing a fan for a bathroom, they focus solely on design. Appearance is important, but without suitable technical properties, the device will not cope with the task assigned to it. Consider the parameters that play a decisive role in the purchase.

Technical characteristics of bathroom appliances

A fan has much less nuances than a refrigerator or a washing machine, however, for each room, each characteristic is important:

  • device performance, reflecting the speed and volume of air exchange in the room;
  • noise level;
  • safety (moisture protection).

Performance is necessarily indicated in the technical description of the device. Average indicators are in the range of 50-250 m³ / h.

The performance of the noise varies from 25 to 50 dB. The lower the noise figure, the quieter the fan runs, respectively, the calmer the situation in the house. Ideal are 25-30 dB parameters. They are required if the device operates in night mode.

Carefully consider the choice of powerful models in which the noise level reaches a maximum. Our other material has a rating of the best silent fans for the bathroom, we suggest you familiarize yourself.

Fan PRO-150
Powerful and durable metal fan PRO-150, with a capacity of 730 m³ / h (rpm - 2800 per minute), but having a high noise level - 48 dB

The fan belongs to electrical devices, so the degree of protection is important. For the bathroom, equipment marked IP 44 and IP 45 is suitable.

The calculation of productivity by the formula

It is not difficult to find the performance of the device - it is indicated in the passport, but how to determine if a fan with such characteristics is suitable for your bathroom? One solution is to make calculations using ready-made formulas. And for starters, you should calculate the volume of the bathroom and find out the optimal rate of air exchange.

The formula for calculating volume is known from school:

V = a x b x h

(the length must be multiplied by the width, then the result - by the height)

For example, the length of the bathroom is 2 m, the width is 1.8 m, the height is 2.5 m. We multiply everything, we get a volume of 9 m³.

Further, the parameters of the air exchange rate for the bathroom will be required.

Air exchange rates
A table that reflects the norms of air exchange in residential premises in accordance with SNiP 31-01-2003 (clause 9.2) and GOST 30494-96. These are the minimum values, more precisely, it is necessary to calculate separately for each room

According to construction standards, for a family of 1-3 people, the multiplicity (the number of fresh air changes per hour) is 6, if there are more than 3 people living, then 8. We multiply the received volume by 9 m³ by 8, we get 72 m³ / h. Therefore, when buying a device, we pay attention to samples with a capacity of 75 m³ / h or slightly higher.

Advanced accessories

The simplest modifications, equipped with a noisy rotating screw and an inconvenient control method, are a thing of the past. Today, bathroom fans are equipped with devices that expand their functionality and even allow you to program the air exchange process. Let's consider some improvements:

  • Non-return valve. This is a special automatic damper that prevents the return of exhaust air back into the room. As soon as the fan shuts off, the flap closes.
  • Motion Sensor. A technical device that responds to the appearance of a person. Its use is not always justified, since short periods of time during which a person is in the bathroom is not enough to ventilate it.
  • Humidity sensor. A device that automatically adjusts on / off depending on the percentage of moisture in the air. According to the requirements of SanPiN (5179-90), the humidity in the room should not exceed 60-65%. If the indicator is higher, the hydrostat is triggered and the fan starts.
  • Timer. A device that allows you to delay turning on the fan for a certain period of time. Suppose a motion sensor has triggered or you have pressed the light-off button - and exactly after 15 (30, 45) minutes, the fan turns on.

An additional function of “airing” is the ability to constantly maintain the most comfortable microclimate in the bathroom. The device constantly works at low speeds, but if necessary, turns on at full power.

Hydrostat connection diagram
Hydrostat connection diagram. If the humidity level in the room rises above the specified value (manual adjustment), the hydrostat activates a fan, which automatically turns off when the set parameters are reached

On our site there are several articles on the selection of exhaust fans for the bathroom. We recommend that you familiarize yourself with them:

  1. Hood to the bathroom: selection rules and installation features
  2. Exhaust fan in the bathroom: how to choose the right + installation rules
  3. Ventilation in the bathroom and toilet: principle of operation, typical schemes and installation features

Connecting several electrical appliances into a single network is not an easy task. Consider some of the most popular hood equipment options.

Connection diagrams of the fan in the bathroom

The ability to use several ways to turn on and adjust the fan presents the choice of the desired circuit. When connecting, you should be guided by the design features, the availability of additional devices and manufacturer's recommendations. The simplest scheme is to install a fan with a built-in on / off device.

Fan connection diagram
For installation, only the fan itself and an electric network of 220 V are required. The device is turned on manually: press the button located on the case or pull the cord (relevant for devices mounted high under the ceiling)

The following diagram shows how to connect a fan in the bathroom to a separate switch. The management process is becoming easier, but you will have to lay a couple of additional cables.

Wiring diagram for fan with switch
Usually, the switch for the hood is mounted next to the switch for the light. The most convenient place is on the wall near the door, in front of the entrance to the bathroom or bathroom

Setting a timer complicates the connection process somewhat: one more additional phase wire is required.

Fan connection diagram with timer
The timer will ensure the inclusion of the device in the delayed time - after 5 ... 30 minutes.The convenience is that the fan does not interfere with water procedures and works during the period when the bathroom is free

The fan connection diagram along with the lighting is convenient from a control point of view, but inefficient. It turns out that the room is ventilated only during the period when the light is on.

This leads either to incomplete ventilation, or to an excessive consumption of electricity. A more appropriate option is to install two-key switch.

Wiring diagram with two-gang switch
The use of a two- or three-key switch increases the functionality of the ventilation and lighting system. The scheme can be improved by connecting a timer or two lighting sources - ceiling and wall

Before choosing a circuit, specify whether there is the possibility of gating and laying additional electrical wires.

Fan installation instructions with timer

For self-installation, we recommend that you purchase an overhead fan that is attached to the ventilation outlet. Before installing the device, carefully study the accompanying technical documentation. You do not need to buy a timer separately, it usually comes complete with diagrams and installation instructions.

Silent Fan
Silent low-noise fan is very popular, it is known for its modern design and long service life (more than 30 thousand hours)

Similar models - Era, CATA, Migliore, VENTS, VULKAN.

Check installation conditions

In order for the installation to proceed without hindrance, you should check whether there is air draft in the common house shaft (or the duct of a private house), whether the hole in the wall is suitable for fixing the selected model, whether the wiring corresponds to the wiring diagram.

Check valve fan
When choosing a convenient appliance with a non-return valve, remember that when it is turned off, the ventilation duct automatically closes, that is, you need to consider natural ventilation options or choose a mode for increasing the duration of the device

Old houses have ventilation openings in bathrooms, bathrooms and kitchens. Usually they are located high under the ceiling and have the same diameter (shape).

However, after major repairs, when additional walls, partitions and false ceilings are being built, there is a possibility of transferring the installation site of the fan, but with the device of an additional channel leading all the way to the same hole.

Vent location
As a rule, the layout is determined by the typical arrangement of ventilation openings - opposite the doors. It is the best solution in terms of efficient air exchange for all ventilation systems.

If you want to make the installation process as quick as possible, prepare in advance the tools and materials that may be required for installation:

  • tape measure, pencil, square;
  • puncher for wall chipping;
  • screwdriver, hammer, pliers;
  • sealant or liquid nails (if necessary);
  • fasteners (dowels, screws).

When choosing a circuit with a switch as a control device, you need to purchase it, as well as the electric wire.

Important nuances of wiring

If you are installing a fan for the first time, get ready for the construction work necessary for wiring the power cable. You may have to remove the plastic ceiling, make holes in the stretch, ditch the walls and dismantle the tiles.

If it is too complicated or expensive, you can choose a simpler way - the outer wiring in the cable channels. This is not so aesthetically pleasing, but fast and inexpensive.

Ventilation for bathroom and toilet
A variant of the combined ventilation system for the bathroom and toilet. Two fans are attached to one ventilation duct, which is equipped with a tee and a pair of check valves

Requirements for wires and sockets:

  • cable cross-section must correspond to the load;
  • Do not mount wires in a metal braid;
  • all cables must be insulated;
  • protection class of sockets - not lower than IP 44;
  • Consider protective shutdown or grounding.

It is strictly forbidden to ground the wires through heating or sewer pipes.

Fan assembly and timer connection

The assembly of the device usually takes place along with the installation, since the case is first attached, then the wires are connected, and at the very end the decorative panel snaps into place.

Wall vent
It looks like a ventilation hole in the wall with wires. The most secure closed wiring diagram is used - the cable was laid during the decoration of the walls and hidden under a layer of plaster

Using the back wall of the housing, which will be mounted directly on the wall, we mark up.

Rear wall mounting
There are several options for fixing the fan housing. This model is fastened with screws, but some use liquid nails or glue.

When the working part of the fan is firmly fixed to the wall, we lead the wires and attach to the terminals of the device.

Wire connection
In order not to make a mistake in connecting the wires and quickly find the clamps inside the case, it is better to first study the technical documentation for the device

If there will be no other devices, install a decorative cover.

Installation of a decorative cover
A decorative panel that covers the internal “working” part of the fan is usually made of plastic. It provides full protection of the device, but under one condition: if it is located at a sufficient distance from water splashes

To connect an exhaust fan with a timer, you must select one of the schemes. Ideally, if the fan is also connected to a switch, a 4-wire cable is required. The core, which is usually used for grounding, is connected to a timer.

Fan connection diagram with timer
The connection diagram of the timer (indicated by a cross). To control the lighting and the fan, a two-key switch is used, the protection is organized using an automatic machine installed in the apartment panel

After installing all the instruments and devices, it is necessary to test to check how the fan functions.

Along with this, the timer is usually set as well - they set the time interval after which the hood will automatically turn on.

Conclusions and useful video on the topic

Video installation instructions for the simplest model:

Detailed instructions for installing a hood with a non-return valve in a private house:

Instructions from the manufacturer of the silent Silent 100 model:

Setting the fan switch:

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 switch), you need to understand the electrical circuits, carefully study the design of the device and, when installing, take into account technical and sanitary standards.

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 first faced this challenge? Please leave your comments in the box below.

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Visitors Comments
  1. Vyacheslav

    A hood in the bathroom is definitely needed. An open door after taking a bath or shower is not an option; all the moisture will go into the apartment. Checked. Condensation immediately settles in the corners and exterior walls (especially in winter).And then, when it does not have time to dry out, the surface begins to become covered with mucus and blacken. So the fan was or will be the most effective, or at worst to do an elementary outlet.

  2. Marina

    When we received the apartment from the developer, the fan in the toilet turned out to be not working. We wrote a request, waited six months, but nevertheless a representative came from the Criminal Code and replaced the fan. But initially, his switch was provided for by a “jumper” hanging from the device itself, but now it is connected to a light switch. Turn on the light - the fan turns on. This is not always convenient. Tell me, how difficult is it to return the previous switching circuit? Type - the usual waybill, from cheap, rather noisy ... Maybe it's easier to replace it with a more modern and expensive?

    • Expert
      Alexey Dedyulin

      Good afternoon, Marina. The electrician will return the previous circuit to you in 5 minutes of work, but at the same time the “twitch” will return. Proceed when choosing a fan primarily from its power.

      I can assume that the ventilation in the toilet works simultaneously for the bathroom. If there is a through hole on the common wall of the toilet with a bathtub in the upper corner, then calculate the volume of both rooms at once. For clarity, see the figure.

      Details on silent hoods can be found in this article. And in this stuff Good tips for choosing a fan for the bathroom are outlined.

      Attached photos: