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How Vacuum Cleaners Work

How Vacuum Cleaners Work

Maintaining a clean environment whether at home or in the office is essential for your health. If you don’t have a vacuum cleaner, yet, you are risking your respiratory health because dust contains particles which cause such complications.

Vacuum cleaners with HEPA filters keep your environment safe and clean by capturing dust and other particles as small as 0.3 microns from your floors and surfaces.

Could it be you have not yet bought a vacuum cleaner because you do not understand how they work? In this article, we are going to elaborate on how vacuum cleaners work. The fact that most vacuum owners do not understand how the machine does its magic will surprise you.

Let’s get into it…

The Science behind Vacuum Cleaners

The physics of vacuum cleaners is simple. I could say as simple as it is to use them. We will divide the process into three steps as discussed below:

1. Creating negative pressure

Vacuum cleaners apply the principle of creating a pressure difference hence suction. For materials to flow from one point to the other, there must be a difference in pressure and this is the working principle of vacuum cleaners.

This is the same principle that applies when using a straw. As you suck up juice using a straw, the pressure at the bottom of the straw drops compared to that at the top of the straw. This pressure difference brings about suction, pushing juice into your mouth.

For vacuum cleaners, the electric or battery-powered motor spins a fan which leads to airflow. As air is being pushed forward, air pressure increases in front of the fan and drops behind it. This pressure drop behind the fan creates a partial vacuum inside the vacuum cleaner resulting in suction.

Air goes into the vacuum cleaner through the intake port and leaves through the exhaust port allowing the motor to continue working.

2. Trapping dust, dirt, and debris

As long as that the fan is still spinning, there will be a constant stream of air entering and exiting the vacuum cleaner, and this results in friction. The stream of air disturbs dust and debris on the floor and carries them through a pipe into a dust bag or dust canister.

Note that for the dust particles to be sucked into the vacuum, they must be loose and light. Also, the vacuum must produce enough suction.

To remove embedded debris and dirt from carpets, some vacuum cleaners employ rotating brushes at the intake port to increase friction.

The debris and other particles trapped in the dust bag or dust canister cannot escape. While the dust bag can trap dust particles, it cannot trap the air that came in carrying all the contaminants.

Finally, the clean air finds its way out of the vacuum cleaner through the exhaust port.

3. Cleaning and releasing exhaust air

Is the air that leaves the vacuum safe for breathing? It is not, because air contains tiny air pollutants like allergens and bacteria which may escape from the dirt bag or dust bin. Therefore, before the air flows into your space, it passes through filters.

However, filtration efficiency largely depends on the type of filters inside the vacuum. The most commonly used and effective filters are HEPA filters which trap particles as small as 0.3 microns in diameter. After air passes through these filters, it is safe for breathing.

Watch the below YouTube video by SharkClean to see how a vacuum cleaner sucks up dust and dirt:

Factors Affecting the Suction Power of a Vacuum Cleaner

As mentioned earlier, the suction power determines dirt pick up. For the best performance, you should get a powerful vacuum cleaner. The strength of the suction power depends on:

Power of the motor

The wattage of the motor determines the speed of the fan. For a vacuum cleaner to create sufficient suction power, the fan must spin faster. So, you should be keen on the wattage of the motor when purchasing a vacuum cleaner.

Clogged air path

After vacuuming for a while, the dust cup will be filled with dirt, and if not emptied it results in the loss of suction power. With a filled-up dust cup or dust bag, there will be a lot of resistance as air tries to find its way out. To avoid such instances, empty your dust bags often.

Also, vacuum cleaners that have cyclonic technology actively prevent large particles from clogging the filters. This results in constant fade-free suction as you vacuum.

Size of the intake port

Narrow intake ports suck in air at high speed creating stronger suction power. If you want a vacuum cleaner to help you with heavy-duty tasks go for models with narrow entry ports.

Essential vacuum cleaner parts

These are the parts that make the vacuuming process possible:

  • Motor – This is the heart of a vacuum cleaner, so it must be on and functional for the device to work. If your motor dies, your vacuum cleaner is dead too you may have to replace it.
  • Brushroll (or beater bar) – this is found on the floor nozzle and rotates to agitate and dust and dirt so that it can be easily sucked into the vacuum.
  • Intake port – This is the part that allows air and dust particles to be drawn in the vacuum cleaner. Most intake ports have a rotating brush to increase friction and remove embedded dirt in carpets.
  • Exhaust port – With air coming in, it must go out and this happens through the exhaust port. The air coming out should be clean, therefore it is advisable to keep your collection bags empty and filters clean.
  • Fan – The internal fan has blades that spin to create a pressure drop and hence suction power. For the vacuum cleaner to continue working there must be a continuous flow of air and this can only happen if the fan is spinning.
  • Filters – Filters ensure that only clean air is blown back into the air. Most vacuums have a pre-filter and an additional filter (usually HEPA).
  • Dirt bag or canister – This is where dirt is stored once it enters the vacuum. The dirt bin should be emptied often to maintain suction power. If your vacuum uses a bag, replace it once it reaches halfway or three-quarters full. Some vacuums have full-bag indicators.
  • Source of power – A vacuum can either be corded whereby you plug it into a power outlet or cordless (uses batteries, usually lithium-ion).


There we go, we have explained how a vacuum cleaner works and it is not rocket science as you would have expected. It is as simple as drinking your favorite juice using a straw. The straw and vacuum cleaner operates on the principle of creating a pressure difference which results in suction.

Also, we have mentioned some essential parts of a vacuum cleaner including the motor, an intake port, exhaust port, fan, dust bag or dust canister, filters, and the power source.

There are different types of vacuum cleaners such as Shark vacuums and Dysons, but they all operate under the principle of creating negative pressure to remove dust and dust particles from your floors and surfaces.

Hope you enjoyed this tutorial. Feel free to ask anything in the comments section below.

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