The basic principle on which a vacuum cleaner operates is called "suction". Suction again works on the fundamental concept of pressure. For example, when you sip Coke through a straw, the pressure on the mouth end of the straw is reduced as a result of which the pressure at the inserted end of the straw increases and Coke flows. This is the simplest implementation of a suction mechanism.

The same suction mechanism is what makes a vacuum cleaner work. Only, it is not such a simple implementation of suction mechanism. This article deals with workings of different kinds of vacuum cleaners based on certain principles of physics.

The internal structure of a vacuum cleaner is very simple although it looks a little complicated from the outside. It is made up of six essential components. First is the inlet, the point from where the vacuum cleaner sucks up the debris and dust from your home or office. This end of the vacuum cleaner usually has a host of accessories shaped in various ways to help you clean. Second is the exhaust, a vent built into vacuum cleaner either to jet out the air coming in through the inlet due to suction, or to suck air when you use the vacuum cleaner in the "blow" mode. Third is an electric motor which helps to produce suction. Fourth, is a fan to start and keep the suction mechanism running. Fifth is a porous bag to collect and filter the sucked air of dust and debris that you have collected through the inlet. Last is the housing or the cabinet in which all these components are arranged in an efficient manner to facilitate the efficient usage of the vacuum cleaner. To use the blow mechanism of your vacuum cleaner, the fan has to rotate the other way. Many vacuum cleaners have this feature built in.

As all of us are aware, a vacuum cleaner works on electricity. Once it is plugged and turned on, the electric motor comes on and rotates the fan. The fan has angular blades, made specifically at a certain angle. Once the fan starts running, the blades push the air towards the exhaust outlet. When this process begins the air pressure increases in front of the fan and reduces behind the fan. This drop of pressure creates a suction or partial vacuum. As air always moves from high pressure areas to low pressure areas, the ambient air tries to move into the low pressure area or the partial vacuum, rushing in through the inlet port. As long as the fan is working and the inlet is open, a constant flow of air is created moving in through the inlet and out through the exhaust via the porous bag.

This constant stream of air running through the inlet can be harnessed using various attachments provided by the manufacturer of the vacuum cleaner. By attaching these various kinds of noses with a flexible pipe to the inlet, the vacuum cleaner can be directed to the dust or debris in various nooks and corners of the house or office. Due to the force of the air, dust and debris gets sucked into the vacuum cleaner. This air mixed with dust and debris after entering the vacuum cleaner has to pass through the porous bag which filters out the air but retains the dust and debris. Thus the cleaning operation is completed by accumulating the dust and debris in the porous bag. This bag can later be taken out and cleaned or disposed of after a few uses.

Vacuum cleaners are of various types. The first generation of vacuum cleaners were invented in mid 1800's which were hand operated. They had bellows through which the suction was created manually. Electric vacuum cleaners came into vogue in early 1900's but were generally viewed as luxury items for many years.

A very popular version of the electric vacuum cleaners is the central vacuum cleaner. This system has a large fan outside the house or office and has various vents connecting through the walls. A flexible pipe can be attached to any of these vents to clean the area. The dust is collected in a large canister outside the house and can be emptied and cleaned as per convenience, a few times a year.

There is a wet/dry vacuum cleaner available for the purpose of cleaning solids as well as liquids. In these kinds of vacuum cleaners the collection method is a little different, since liquids cannot be stored in porous bags. Usually external buckets are used.

A recent version of the traditional vacuum cleaner is called the cyclone vacuum cleaner. This variation does not have a porous bag collector. It has a maze of spiral pipes through which the air is passed, as a result of which the dust and debris in the air experiences a centrifugal forces and falls away from the air, collecting inside the cylinder.

This is not the end of technology; we would see more innovative designs of the vacuum cleaner that has become a part of every household in the years to come.