Connecting an exhaust fan in the bathroom and toilet: analysis of diagrams and tips for installing equipment
It happens that you take a hot bath or shower, steam, relax - it’s time to get yourself in order. You go up to the mirror and it’s completely foggy, and even a towel can’t dry it. Or the smell from the previous visitor or an intrusive air freshener lingers in the toilet for a long time. Situations familiar? Connecting an exhaust fan in the bathroom and toilet, a common one or two separate ones, will help solve such problems.
The quality of bathroom ventilation should not be neglected, because this is a matter of not only convenience, but also safety. Over time, mold and mildew grow along the bathroom, in the corners and in the seams between the tiles, which are dangerous to human health. It is often possible to completely remove them only during a major overhaul, so the purchase and installation of an exhaust fan more than pays off, preventing such problems.
In this article we will tell you how to organize a forced ventilation system for a bathroom, what to look for when purchasing equipment, and how to install and connect everything yourself. Let's look at connection diagram options suitable for different fan models and conditions of use, and also give some useful tips about ventilation in the bathroom and toilet.
The content of the article:
Selecting a fan and starting method
There are many on the market exhaust fan models, including for the bathroom.They differ not only in size and appearance. There are a number of characteristics that should be taken into account when choosing and purchasing.
The first thing that determines the connection diagram for a fan for extracting air from a bathroom is the method of starting it.
Depending on the model, there are the following options:
- Turning on the fan body with a button or a cord - they are the easiest to connect, but reaching up to the ceiling every time is not very convenient.
- Starting with a separate switch or in parallel with lighting. The fan itself also has only 2 wires, but the possible connection diagrams are more complex and varied. Including, with an external timer or hygrometer, motion or door opening sensor.
- Control via built-in timer or hygrometer. Such models are connected with a three-wire wire.
- Remote control via remote control. These models combine the ease of connection of the first option and maximum ease of use, but they are also the most expensive.
In addition, not every exhaust fan is suitable for a bathroom. The fact is that this is electrical equipment, and to work in conditions of high humidity, the protection class must be at least IP45, which is confirmed in the documents.
In this case, each digit of the marking should be taken into account separately, that is, IP62 protection is not suitable, since the second digit indicates resistance to moisture; it must be at least 5.
In practice, protection is implemented in the form of insulated connection contacts, a hidden or moisture-resistant control board, and a sealed motor housing.
You should also decide on the type of device design. Axial models are cheaper, but noisier because the air passes directly through them. Centrifugal fans form vortex flows that push air in a circle - this is much quieter. In addition, for a private house you can choose which ones are installed inside the ventilation duct, and not at the exit from it.
Another critical parameter is the power and performance of the fan. To do this, the volume of the room must be multiplied by 6 - 8, depending on the number of residents. The resulting figure is the minimum required volume of air exchange per hour.
A fan that is too weak will not do its job well and will have to be left on for a long time. Too powerful will not only add strong drafts, but can also provoke a reverse flow of air from the common ventilation shaft, with all the neighboring odors.
Also pay attention to the diameter of the fan. If it does not match the diameter of the existing ventilation hole, installation will require additional pipe and construction foam or a hammer drill, as well as significantly more effort.
The comfort of use is significantly affected by the noise of the equipment. Quiet models produce no more than 25-30 dB, less successful solutions produce about 50 dB, and sometimes more.
In addition to the above parameters, pay attention to whether it is equipped check valve fan, ventilation function, mode switch, display with temperature and humidity indication. Design solutions include original or replacement protective panels, sometimes backlit.
Fan wiring diagrams
The most important part of installing a ventilation system is connecting the electrical wiring. The correctness, efficiency and safety of the system, as well as the ease of use of it, depend on this. It often happens that no one uses the installed fan in the bathroom just because it is inconvenient to turn it on or off.
Different connection schemes, as well as built-in and external devices allow you to automate fan control or minimize the cost of its installation.
Devices with a switch on the body
An inexpensive and reliable option is to install a fan with a built-in switch. It can be connected to an outlet or directly to the wire that supplies electricity to the apartment, whichever is closer.
The most expensive models, which are controlled by remote control, are connected in the same way. They also have a shutdown button on the body - an emergency one.
However, before you connect the fan directly to the outlet, think about whether you will be reaching for the button or cord on the body of the unit every time? After all, it needs to be installed under the ceiling, where steam accumulates. Of course, the lace can be lengthened - but this is not aesthetically pleasing, and it is not always convenient.
The advantages of such a connection include ventilation control from inside the bathroom - after all, according to the PUE, any other switches and controls for electrical appliances should be located outside, in the corridor.
Connecting the fan to the lighting
The simplest and most cost-effective option for arranging forced ventilation in a bathroom is to connect the fan to the nearest light bulb, using a minimum of wires and effort. In this case, the hood will work exactly as long as the light is on.
Installing a fan with three connection wires is somewhat more difficult. Such a unit requires constant power supply to the board, so both phase and zero are drawn to it directly from the box.
The switch opens the additional phase wire that controls the timer. All connections are described in more detail in the diagrams below.
Connecting through a box is safer, since all connections are located outside the bathroom, but has the same operational disadvantages as connecting to a light bulb. On the one hand, you will never forget to turn on the hood, you will need few wires, and you can hide them even after covering the walls - in the ceiling.
On the other hand, few people will like drafts and noise while bathing, and the operating time of the light may not be enough for effective ventilation. As a result, you have to leave the lighting on after leaving the bathroom or toilet, which means additional energy consumption.
The presence of a built-in timer in the exhaust fan eliminates these disadvantages: in bath mode it will turn on only after the lights are turned off and work for a specified time, and in the toilet it will start along with the lighting.
Connection via switch
This connection scheme is the most universal, reliable and widespread. You can use it to connect any fan model and control it manually, regardless of lighting.
Connecting a fan with a timer is carried out in almost the same way as we described in the previous paragraph about the connections in the junction box. The fundamental difference is that the phase wire of the fan is not closed together with the lighting phase, but separately - to the separate wires of the two-key switch.
To connect simple models without a built-in timer in this way, it is enough to connect the zero wire from the distribution box directly to the fan, and the phase wire from the switch. If a one-button light switch is already installed, it replaced by two-key, and the wire from it to the box is three-wire. The phase wire to power the fan is connected to the new core.
Such a circuit can malfunction most often for one reason: phase and zero are mixed up.
If diode bulbs blink in the bathroom when the lights are turned off, and the electronically controlled fan behaves strangely, it makes sense to open the junction box and double-check the presence of a phase on the wire leading to the switch.
Read more about how to connect a fan to a switch Further.
Including an external sensor in the circuit
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 sensor or a door opening sensor.
The most effective ventilation would be in the bathroom, controlled by a humidity sensor, and in the toilet - by a timer or air pollution sensor.
It is worth noting that external sensors, as a rule, are much less durable and reliable in bathroom conditions than those built into the fan.
Fan installation procedure
As in any construction work, the ventilation system first needs to be designed. It is better to do this at the very beginning of the bathroom renovation, in order to be able to hide all communications in the walls and under the ceiling.
If we are talking about a bathroom in an apartment where there is already a hole in the wall into a common ventilation duct, you just need to turn natural ventilation into forced ventilation. To do this, it is enough to decide on the fan model and the diagram of its connection to electricity.
In a private house, you usually have to build a system from scratch, leading the ventilation pipe to the street through the roof, or less often through the wall. In this case, it is necessary not only to think through everything, but also to draw up a plan diagram, according to which it will be convenient to count the necessary materials and carry out installation.
It is worth checking the presence of natural draft in the existing shaft, and if it is completely absent, contact the housing office for cleaning. For effective air exchange, it is better to place the hood opposite the door or flow valve, if there is one.
The next stage is purchasing everything you need. It’s worth purchasing in advance even what will be installed at the very end of the repair, because another fan model may not connect to the wires already connected.
Having figured out how to connect the purchased fan and selected a ventilation scheme, you can begin renovating the bathroom.
During the decorative finishing of walls and ceilings, wires are laid in corrugated insulating tubes, if necessary, a ventilation duct is constructed and the size of the hole for the fan is adjusted. Connecting the wiring and installing switches is also carried out at this stage.
The fan itself is installed after finishing is completed. The installation procedure is as follows:
- Make sure that the wires leading out to the fan are de-energized.
- Remove the front panel, insert the housing into the hole and mark the mounting locations on the tile with a marker.
- Drill holes using a drill with a ceramic drill, and hammer dowels into them. This step can be neglected completely or only part of the provided fasteners can be used. Plastic fans weigh little, usually liquid nails or polymer glue are enough to fix them.
- Even when mounted with self-tapping screws, the perimeter of the fan housing must be coated with silicone or other polymer to absorb vibrations and prevent noise.
- Insert the housing into the hole, check the level (for models with a square front) and press firmly until the sealant sets.
- Connect the wires to the terminals of the device and secure it so that there are no bare areas left.
- Turn on ventilation, check operation in all provided modes.
- Install the front panel.
This procedure is universal and is suitable for overhead fans of any model. It also does not matter whether the fan is installed in the wall or in the ceiling - only the installation is different channel models.
If the fan is designed with a timer, hygrometer, mode switch or other equipment, do not forget to set it up before the decorative panel is put on.
Often, from the factory, the timer adjustment screw is turned out to the minimum - select the required operating time experimentally.
There may also be a mode switch, which looks like 3 or 4 metal pins with a removable jumper on two of them.
In the “toilet” mode, the fan starts immediately, simultaneously with the light turning on, and runs for the time set by the timer. In the “bathroom” mode, the start signal is to turn off the lights, so noise and drafts will not disturb you in the shower.
The built-in hygrometer can be set to a certain humidity level at which the fan will start.
Common mistakes and additional tips
Fan connection errors can cause not only incorrect operation of the hood, but also a short circuit or fire. Do not forget that the bathroom is a room with high humidity, which means it is especially dangerous for electrical appliances and wiring.
In order to arrange ventilation without errors on the first try, consider these tips:
- The fewer bends and the simpler the design of the ventilation duct, the better the traction.
- With a single ventilation system for a separate bathroom, air should move from the bathtub to the toilet, and not vice versa.
- For all wire connections, use terminal blocks, not electrical tape.
- Strip exactly the part of the wire that will go into the terminal block.
- Check that there is a mosquito net in the fan. If suddenly it is not there, add it, because mosquitoes and other insects feel great in warm, damp ventilation shafts.
- In a private house, be sure to insulate the part of the ventilation duct or shaft passing through unheated rooms. Otherwise, there will be no traction in cold weather.
- Don't neglect grounding for metal fans.
In addition, to prevent the fan from interfering with natural ventilation when it is turned off, you can use double rectangular grilles, with a hole for the fan at the top and a regular grill underneath.
If it is not possible to install a double grille, you can maintain natural ventilation by placing foam plastic legs 1 - 2 cm under the corners of the body, in the places where they are fastened with self-tapping screws. As a rule, the ventilation window is square and the fan housing is round, and these gaps are enough for air circulation.
Please note that even an ideally installed and sufficiently powerful fan will not work effectively if there is not sufficient supply ventilation. Usually it is provided by a gap of 1.5–2 cm under the door to the bathroom, but for beauty it can be replaced with a special grille that cuts into the bottom of the door.
Also, make sure that fresh air gets into your home at all, because after installing plastic windows and new doors, insulating the walls and concrete screed on the floor, the apartment turns out to be hermetically sealed, like a thermos.
Additionally, the exhaust fan may need cleaning. Therefore, we recommend that you also read the step-by-step instructions for disassembling and cleaning the device. More details - go to link.
Conclusions and useful video on the topic
The construction of a ventilation duct for autonomous ventilation of a toilet and bathroom with only one shaft is clearly shown in this video:
Connecting a simple fan is described in detail here:
To summarize, we can say that it is quite possible to independently arrange an effective ventilation system in an apartment, but you need to be careful and think through everything carefully in advance. If you are not confident in your abilities, entrust the job to a specialist, because mistakes in working with electrical wiring can lead to dire consequences.
Have you ever installed a fan in a bathroom or toilet? Please tell us what connection diagram you used and were there any difficulties in installation? Leave your comments, share your experience - the communication block is located under the article.
