Question

Why is a ventilator provided in a room?

Answer 1

Hint: Ventilation is a system provided in every room and building in order to provide a proper air circulation. It helps to get rid of smoke, cooking odours and pollutants. There are different types of ventilation like natural ventilation, mechanical ventilation and mixed-mode ventilation. We can also assess ventilation performance.

Complete step by step solution:
Ventilators and windows are provided in a room in order to maintain a proper flow of air within the room. A proper ventilation is maintained in a room because of conventional currents of air. The process of continuous replacement of warm, impure air inside a room with that of the fresh air from outside is called ventilation.
Because of breathing the $C{O_2}$ level and humidity of the air inside the room rises. This moist warm air containing $C{O_2}$ will be less dense and lighter so rises up. It then escapes through the ventilator decreasing the air pressure inside the room. Also makes way for the fresh air to get inside and thereby maintaining a continuous air circulation within the room by convection currents.

Additional information:
While building ventilation three basic elements has to be taken care off:
Ventilation rate: the amount of outdoor air that is sent outward and the quality of air.
Airflow direction: the overall airflow direction in a building which should be from dirt zone to clean zone
Air distribution or airflow pattern: the external air should be delivered to each part of the space in an efficient manner and the airborne pollutants generated in each part of the space should also be removed in an efficient manner.

Note:
Natural ventilation happens when outdoor air like winds drive in through the building openings. It depends mostly on the climate.
Mechanical ventilation: It happens through the application of mechanical fans installed in windows or walls.
Mixed-mode ventilation: It depends on the natural forces like wind but if the natural ventilation rate is too low then it uses artificial ventilation.