First, the kitchen (the first vent is right there) will not leave the smells and products of domestic gas burning if you have a gas stove. Poor exhaust from a gas boiler or column can lead to almost no traction, which in some cases causes poisoning of residents with carbon monoxide, but it is not at all desirable to clean ductwork yourself.
Secondly, inoperative ventilation in the bathroom will increase the time required to dry the room (reducing the amount of water vapor in the air), which will subsequently become the main reason for the appearance of black spots of mold and fungus on the walls and ceiling of the room.
Thirdly, clogged ventilation in the toilet (if the channel is common for several apartments) can start to work “in the opposite direction” and you can fully feel all the smells from the neighboring bathroom.
Clean ductwork your will cut down on dust in your home for a long time to come.
There are many reasons to clean the ductwork in your home. When ductwork are clean, the heating system lasts longer (because there is less dirt wearing out its components), we dust less often, and the air we breathe at home is cleaner. For those of us with allergies, this should be a welcome improvement.
Probably you don’t own a high-powered, truck-mounted vacuum system with 150 foot-hoses; perhaps you can’t afford the cost of such service.
There are many different designs of ductwork systems, such as attic systems and underground systems, but the theory of clean ductwork systems is the same. You may not be able to access all parts of these systems (for example, underground ducts), but you can make a difference in your air quality by cleaning the parts of the system that you can reach.