You have used the vacuum cleaner at home to remove dust from the floors, walls, upholstery, and other places. Does it not feel great to hear the ‘WHIRR’ sound of the machine as it sucks in the dust?
But have you ever wondered what happens to the air sucked inside the machine with the dust? Does it remain inside the machine? If so, the machine would have burst long ago.
How does a vacuum cleaner work?
The machine sucks the dust in along with air and deposits the dust inside the container or bag that you empty or replace frequently.
The air sucked inside the machine is let off as exhaust. But in that case, the air coming out of the exhaust should be polluted. No, it is not because filters in the vacuum cleaner filter out harmful bacteria, dust, allergens, and other contaminants.
Why do vacuum cleaners need a filter?
So, the purpose of having filters in vacuum cleaners is to purify the air before releasing it back into the room. If it were not for the filters inside the machine, all you would do is remove dust from one place and deposit it elsewhere in the room.
Categories of vacuum cleaner filters
Generally, vacuum cleaner filters are classified into two types, primary and secondary filters.
The Primary Filter is the main filter that collects the dust inside the machine’s canister. You have bagged and bagless vacuum cleaners.
The bag acts as the primary filter in a bagged vacuum cleaner. The bag is made of material having minute holes allowing the air to pass through it while filtering the dust and contaminants inside it.
Bagless vacuum cleaners have a pre-filter placed before the dirt canister. Therefore, the dirt canister can also act as a filter. In addition, the best vacuum cleaners have another filter placed after the canister to purify the air further before the exhaust process.
Cyclonic vacuum cleaners work differently because the cyclonic motion pushes the heavier dust particles outwards and gets trapped in the filters.
All vacuum cleaners do not have a secondary filter. It is an additional attachment after the primary filter/bag/dirt canister. The purpose is to ensure the removal of 100% dust before releasing the air back into the room.
However, you must note that the allergens can still escape into the air despite the filtration process. Therefore, the design of the vacuum cleaner filter plays a critical role in trapping the contaminants inside the machine.
Different Types of Vacuum Cleaner Filters
Vacuum cleaner filters are available in multiple types, depending on the appliance and the filtering technology used.
Usually, cartridge filters are made of synthetic or foam products. They can capture minute dust particles up to 3.0 microns in size. These filters are usually cylindrical and fitted into the airtight space inside the vacuum cleaning machine. They are available in varying sizes according to the brand model. They are disposable and need replacement frequently. Users should note replacing them with filters of identical size.
Cartridge filters are further classified into HEPA and ULPA filters.
HEPA Filters – High-Efficiency Particulate Air filters
HEPA filters are usually made of glass fibers arranged in the form of a mesh through which air can pass. However, the contaminants get trapped in the mesh. HEPA filters can trap 99.9% of contaminants up to 0.3 microns or larger, such as pollen, dust mites, pet dander, etc.
Though HEPA filters trap almost all contaminants, they are inefficient in removing volatile organic compounds such as the residue of burning fuel like coal, wood, petrol, and diesel. Such contaminants require an additional activated carbon filter to absorb and prevent them from releasing into the air.
Usually, vacuum cleaners have pre-filters to capture heavy dust particles to enhance the HEPA filter’s efficiency and durability. HEPA filters work best when they are fitted airtight into the vacuum cleaner. Gaps in the fitting reduce the filter’s efficiency.
The primary disadvantage of HEPA filters is that they are not reusable or washable. The only solution is to replace them regularly. Therefore, it increases the maintenance costs substantially.
ULPA Filters – Ultra Low Penetration Air Filters
ULPA filters are like HEPA filters but more efficient because they can trap up to 99.999% of contaminants of diameter 0.1 microns and larger. In comparison, HEPA filters can remove contaminants of diameter size 0.3 microns or larger.
Like HEPA filters, the ULPA filters are also made of glass fibers in the form of a thick mesh to trap contaminants and allow air molecules to pass through comfortably.
HEPA and ULPA filters are efficient but not washable or reusable. In contrast, cloth filters are washable. Hence, they can be removed, washed, and reused. Therefore, these filters are more convenient.
Usually, the bagged vacuum cleaners feature cloth filters with minute pores to allow air molecules to pass through while trapping the dust inside the bag. These bags can be emptied and cleaned when they become full.
Compared to HEPA and ULPA filters, cloth filters are cheaper. However, they are not as efficient.
Foam filters are generally used as secondary filters. These filters can trap dust particles and allow air to pass through. The bagless vacuum cleaners usually have foam filters behind the cartridge to purify the air further before releasing it through the exhaust.
Activated Carbon Filters
We have discussed whether HEPA and ULPA filters do not trap volatile organic compounds. Therefore, vacuum cleaners feature an additional activated carbon filter as a secondary filter to cater to organic and gaseous impurities. In addition, using activated carbon filters removes foul odor from the air released through the exhaust.
Disk filters get their name from their shape, which is in the form of a disk. They are usually made of paper or cloth. Usually, robotic vacuum cleaners feature disc filters because they can be easily integrated into these machines. In addition, the disk filters can handle moderately sized contaminants.
Besides the five different types of filters discussed above, vacuum cleaners have customized options, like allergen, scented, Microfresh, and washable filters.
- Allergen filters are made of cloth and can trap pollen, dust, and other minute contaminant particles. However, HEPA filters are more efficient.
- Scented filters feature chemical additives that emit a pleasant smell to the air released through the exhaust. However, these filters are not as good as activated carbon filters because the scented chemicals can mask the odor but not eliminate the volatile organic compounds.
- Microfresh filters contain non-toxic chemicals that sterilize and disinfect the exhaust air by destroying airborne disease-causing bacteria and viruses.
- Washable filters help in reducing vacuum cleaner maintenance costs because of their reusability after washing them.
This table should help summarize the different types of vacuum cleaner filters.
|Material||What can it remove||Washable and reusability|
|HEPA Filter||Glass fibers in the form of a mesh||Pollutants up to 0.3 microns in diameter||Usually not washable|
|ULPA Filter||Glass fibers in the form of a mesh||Pollutants up to 0.12 microns in diameter||Usually not washable|
|Cloth Filter||Cloth||Large size pollutants||Washable and reusable|
|Foam Filter||Foam||Small size particles||Washable and reusable|
|Disk Filter||Cloth or paper||Small size particles||Usually not washable|
Almost all vacuum cleaners use the different types of filters discussed above for filtering the exhaust air before releasing it into the room. Usually, vacuum cleaners combine these filters because they supplement each other well.