When you cover the end of a vacuum cleaner, it starts getting louder because you are creating a restriction in the airflow. A vacuum cleaner is designed to work efficiently when air can freely flow through it. When you cover the end, you are blocking the outlet through which the air would normally escape.
Vacuum cleaners rely on a strong airflow to create suction and pick up dirt and debris. The motor inside the vacuum creates a pressure difference, with lower pressure inside the vacuum cleaner and higher pressure outside. This pressure difference causes air to rush into the vacuum cleaner, carrying dirt and debris with it.
When you cover the end, the air can no longer escape easily, and the pressure inside the vacuum increases. The increased pressure leads to several effects:
Increased motor speed: Many modern vacuum cleaners have safety mechanisms or control systems that detect changes in airflow and increase the motor speed to compensate for the increased back pressure. This increase in motor speed results in a louder noise.
Vibrations: The increased pressure and airflow disruption can cause the vacuum cleaner's components to vibrate more, producing additional noise.
Reduced suction: With the restricted airflow, the vacuum cleaner's ability to pick up dirt and debris is reduced because the suction power is compromised.
It's essential not to block the airflow of a vacuum cleaner intentionally, as it can put extra strain on the motor and potentially damage the vacuum over time. It's best to use the vacuum cleaner as intended and avoid covering the end to ensure optimal performance and longevity.