How to Organize an Exhaust System in the Kitchen, Bathroom, and Toilet

Any room with high humidity requires ventilation. In the kitchen, bathroom, and toilet, you have probably noticed plastic grilles under the ceiling through which air leaves the room into the ventilation ducts and then outside. In houses built during the Soviet era, ventilation ducts are usually clogged with dust, construction debris, cobwebs, etc., so windows often have to be opened for airing. In this case, the ventilation problem can be solved quite easily – you only need to install an exhaust electric fan, which will effectively ventilate the room, even if the ventilation ducts are heavily clogged.

To check how clogged the ventilation system is, take an open flame source – matches, a candle, or a lighter – and bring it to the ventilation grille in the kitchen, bathroom, and toilet. If the flame bends toward the grille, it means the ventilation is still “alive,” so a simple fan will be enough. If the flame does not move, you will need to buy a centrifugal fan. It is usually two to three times more expensive than a regular fan but also much more powerful, so it becomes necessary.

However, there is also the other side of the coin. If you install a very powerful exhaust fan, the air with kitchen or toilet odors, as well as dust and dirt from the ventilation system, may not go outside as intended, but instead to your neighbors, since their duct is closer and may be less clogged.

For a toilet, a regular exhaust fan will be sufficient if the ventilation system in the building still functions to some extent. For one “seat,” choose a fan with a capacity of about 30 cubic meters per hour and install it in place of the ventilation grille. The cheapest fans are connected to the light switch or have a built-in cord switch. “Advanced” fans are equipped with a timer or a motion sensor – meaning that after you leave the toilet, the fan will continue to operate for 5…15 minutes (the shutdown time can be adjusted).

For the bathroom, the same type of fan as for the toilet will do, but it is better to choose a more expensive splash-proof model – it is resistant to water splashes. It is also advisable to install a humidity sensor together with the fan, which will automatically turn it on and off depending on the humidity level. As a result, the air will not be damp, mirrors and pipes will not fog up, and the walls will not become moldy over time.

In the kitchen, you will need a more powerful fan since the need for fresh air there is much greater. The following formula is usually used: take the volume of the kitchen in cubic meters, multiply it by 10, and subtract the volume taken up by furniture. For example, for a standard 6 m² kitchen, a fan with a capacity of 120–180 m³/h will suffice, and for a 10 m² kitchen, it is better to buy a fan of 220–300 m³/h. A kitchen fan can be installed not only in the ventilation opening but also in the window vent. In this case, choose a model that works both for exhaust and supply, so you can “pump” fresh evening air into the kitchen. Sometimes built-in ventilation valves such as Aereco or similar devices are installed in windows. Buying and installing a fan with a humidity sensor allows you to automatically regulate air quality in the kitchen.

In modern kitchens, it is customary to install hoods (extractor hoods) instead of fans. They can operate as exhaust fans, removing used air from above the stove, or as recirculation systems, simply cleaning the air with filters. If an air conditioner is installed in the kitchen, it works more efficiently together with the hood, which removes heated air outside. At the same time, this air is cleaned and dried with built-in filters, preventing the ventilation ducts from becoming clogged with grease and protecting them from corrosion.

An exhaust fan can also be installed in living rooms. The calculation formula is similar to the kitchen, but instead of multiplying by 10, you multiply by 3. An even simpler option is to choose a fan with a capacity of 30 cubic meters per hour per person.