Filters for ventilation: types, features and disadvantages of each type + how to choose the best

Alexey Dedyulin
Checked by a specialist: Alexey Dedyulin
Author: Oleg Zubarev
Last update: April 2019

Supply air cleaning is an important function of ventilation and air conditioning systems. Filters for ventilation perform this task - the elements trap particles of dust, dirt, allergens and other harmful impurities. The issue of air conditioning is most relevant in the city, near the roadway or industrial zone.

To provide the house with clean air, you need to learn how to choose and change the filter elements in a timely manner, agree? We will help you in resolving these issues.

In the proposed publication, the classification of air purifiers is considered, their purpose and application features are indicated. In addition, we gave practical recommendations on the formation of an integrated filtration ventilation system.

Why air filters are important

If a person has installed a ventilation system in his home, office, production facility, he expects to receive an influx of fresh, clean air, and this is impossible without an effective filtration system. Therefore, in the absence of high-quality cleaning of air masses, the meaning of installing expensive equipment is lost.

Even if the owner does not see the need for this procedure, it will still need to be done to protect the mechanical parts of the system itself.

Third-party particles, including small fragments of branches, insects, grains of sand raised by the wind and dust, can lead to premature wear and breakdown of expensive equipment, and repairs will be more expensive than a package of high-quality filters.

In addition, maintenance will be much more expensive. For example, you will regularly have to reconfigure the system. And since only specialists are capable of performing this operation, each such setup will be expensive.

Synthetic fiber filter
Filters made of polyester fiber are the most popular today. And also in the photo it is seen that the filter material is corrugated - this increases the cleaning efficiency

And this is not the whole list of additional work that has to be done in the absence of an effective filtration system.

Existing varieties of cleaners

The division into species is considered conditional, although it covers all sorts of filter features. This is necessary so that consumers, manufacturers, sellers can better navigate the design features, a variety of materials.

Filtering devices are divided into types, taking into account the following features:

  • by design;
  • purpose, effectiveness;
  • the principle of work.

All design features of air filters are standardized, so several types are highlighted. The same products may be of different efficiencies.

The classification of cleaners makes it easy to select models of the desired designs. For example, pocket filters used for ventilation of various rooms are rough and ultra-efficient.

Types of filter products by design type:

  • Pocket;
  • cassette
  • panel;
  • filtering sleeves.

Pocket filters differ in low resistance, durability, safety, high dust absorption. They are distinguished by the simplicity of design, use, disposal, and also have high fire safety.

Pocket filters
Pocket filters are structurally simple, reliable and safe, therefore they are one of the most popular types

They can be used in various fields (in production, in hospitals, in residential premises). Durable synthetic fibers are used as the material of manufacture. They are stitched, welded structures, similar to pockets that are attached to a rigid frame.

Cassette filters - used in various fields (in production, in catering, pharmaceuticals, everyday life), are distinguished by strength, durability. Advantages include low initial resistance, significant dust absorption.

Rigid construction allows you to cope with any loads. The filter material is made from modern polyester fibers.

Cassette filter
The cassette filters have a rigid structure, therefore they withstand significant loads.

Panel Filters - products for which various raw materials can be used as filter materials, including a metal mesh, polyurethane foam, but modern polyester fibers are most often used.

Such devices can be part of various systems for air purification in production, in everyday life. They are distinguished by practicality, high performance, impressive ability to retain dust.

Filter bags they are the most efficient filters, therefore they are used mainly in production, including chemical plants, tobacco factories, and thermal power plants. Such products can also be used to capture various gases, for example, in the production of aluminum.

Sleeves are the most common filter elements in production, and their use is traditionally considered the most economically feasible. And all because these filters are capable of performing high-quality cleaning of various gases and dust. They can be changed without stopping the process.

Panel filter
Panel filters. They are easy to distinguish, since the frame of such products is always equipped with power elements in the form of a grid

In addition, the sleeves are durable, not very susceptible to operating conditions - they can work at an impressive 280 ° C and significant frost.

In this case, the filtering material is modern polyester fibers, which are often coated with additional layers, for example, membranes to improve the quality of air treatment.

Classification of popular types of filters

For high-quality cleaning, various types of air filters are used for ventilation and air conditioning systems. To potential consumers easily understand their capabilities, such products are divided by efficiency and purpose. The division into different groups is standardized by the state.

Purifier groups by effectiveness and purpose

Domestic GOSTs regulate the scope of filtration devices (R EN R EN 1822-1-2010 and newer R EN 779-2014). If the buyer chooses a foreign-made product, he will not feel the difference in classification, since the same standards have been adopted in the world.

So, filters are:

  • general purpose - this species is most in demand;
  • special purpose - they are used in cases when increased requirements are imposed on the purity of air in any production, in the laboratory, in everyday life.

In turn, the listed species are divided into various classes that accurately indicate their capabilities. The classification shows how much of the pollution is retained.

To verify the compliance of products with requirements, devices are used that calculate the mass concentration of foreign particles before cleaning and after this procedure.

General purpose filters are divided into the following categories:

  • G-class - perform rough cleaning, are used only to protect more accurate parts, ventilation equipment itself;
  • M class - relate to secondary filters, they can be used both in the system and outside it;
  • F – class- products capable of fine cleaning are credited here.

The listed devices can function in all ventilation systems. They are only dust-tight, which is enough in some cases.

If more efficient filtration is needed, then these products are used as part of the system. This is done so that inexpensive general-purpose filters protect expensive high-performance cleaners from the effects of large abrasive particles and debris.

Special filters for ventilation systems are divided into the following categories:

  • E and H-classes - this includes all devices with high efficiency;
  • U-class - products have ultra-high efficiency.

These filter constructions are capable of solving a number of special tasks, for example, capturing odors and fats. They have the greatest efficiency, but their price is significantly higher than that of general-purpose models. Therefore, they are used in situations where this is required by the technological process in any production facility, in the laboratory.

And they are also actively used in domestic conditions, for example, they will help people with weakened immunity, or suffering from allergies, avoid many difficulties.

Filter Classification
Filter classification table depending on the class of cleaning (+)

For the most accurate classification, along with letter designations, additional digital ones are also used, for example, G1, H9, U17. The higher the value indicated by the letter, the more effective the product.

In total there are 17 digital classes, all of them are listed in the relevant state standard specifications. For example, the coarsest of the standardized filters G1 should trap 50-65% of synthetic dust, and G4 no less than 90% of the same particles.

The most accurate products, like U17, are required to capture 99.999995% of contaminants. You can get acquainted with cleaning performance indicators for general information, since in most cases technical documentation, passports contain alphanumeric classes.

Types of filters according to the principle of operation

Since there are various types of air pollution, it is logical to use different types of purifiers to clean it. Actually, they do this by combining products with a different operating principle in the filtering system, which makes it possible to more successfully capture dirt particles.

And also this procedure allows you to make cleaning more economical. The reason is ventilation system designs - The most impacted are durable and cheap fixtures installed pre-installed.

Types of filters according to the principle of operation:

  • mechanical;
  • oil;
  • coal;
  • spongy;
  • HEPA.

Mechanical filters- designed to clean the supply air from sufficiently large particles, which include dust, animal hair, insects, etc. Such products are used to filter dirt 5-10 microns in size.

Particularity of the particles of the indicated sizes is that there are few of them, but they significantly accelerate the wear of the equipment of the ventilation system itself.

And also more effective and expensive precision cleaning products quickly become unusable, which leads to disruptions in technological processes and a worsening microclimate in the office and at home.

To prevent the above destructive processes, mechanical filters are installed in almost any air conditioning, ventilation system and perform preliminary retention of dust and other particles. Typically, such products are made from fibrous synthetic materials having a mesh structure.

Mechanical filters
Mechanical filters are present in almost every ventilation system. They take the first blow in the form of dust and other large particles that fill the exhaust air

To give strength, various modern adhesives are often used. In many cases, the used product must be disposed of, but there are models that can be cleaned by washing or using pressure air. This makes them reusable, which is beneficial and practical.

These procedures can be performed in any production and even at home. The disadvantage is that the mechanical filter alone is not able to purify the air.

Oil - cleaners, the main structural element of which is a filter element. Most often it is combined, and consists of durable synthetic fibers, metal nets. But the main feature is the use of mineral oils to increase the cleaning efficiency, which is achieved by sticking dirt to it.

Oil products are used as predisposed filters to capture large particles, which limits their functionality.

Coal models function through adsorption - this is a physical phenomenon in which the pores of one substance absorb another. Such products effectively remove gases, odors.

The carbon filter used for ventilation can only be used with an additional trap for fine dust and grease particles in front of it. The reason lies in the fact that larger grains clog the pores of coal and make the adsorption process ineffective.

The advantage of this type is a sufficient degree of purification at a moderate cost. It is often used in everyday life - it is common carbon filter for hoods. He found application in medicine, pharmaceuticals, in small industries. The disadvantage of such products is the need for regular replacement.

Carbon filter
The carbon filter is not much different from other types, as the filter material is packed in bags of polyester fibers

Sponge Filters- purify the air of sufficiently fine dust and other solid elements. The name comes from filter materials (sponge rubber, polyurethane foam), which, in order to increase efficiency, undergo special processing in order to increase the pore area.

They are used repeatedly, as they can be washed. They are used in everyday life, in production, and in medicine. The disadvantage is that these traps are only suitable for removing dust from the air, although they do it efficiently.

HEPA Filters Designed for highly efficient capture of fine dust particles.Often they are the main component, although it is always necessary to use them with pre-installed filters that will clean the air of large elements of dirt.

The surface of such products is covered with chemical solutions to inhibit various types of bacteria.

They are used wherever there are high requirements for air quality. Since they successfully eliminate allergens (spores, pollen, wool, house dust, and others), they are often used in everyday life. They make cleaners from special paper or synthetic fibers.

HEPA filter
The result of air purification using HEPA filters is close to ideal, but it should be remembered that they can only be used with a predisposed filter

HEPA filters are often installed in household air purifiers.

If you need maximum cleaning efficiency, you should choose ULPA filters that have the same principle of operation as HEPA, but are capable of capturing slightly more dust. All high-performance products are quite expensive, in addition, they have a fragile design.

Innovations in ventilation systems

In addition to the cleaners listed above, new high-tech methods are increasingly being used. For example, photocatalytic filters have recently been used for ventilation systems, but they are quickly becoming in demand.

The reason for the growing popularity lies in the ability to equally effectively deal with various viruses, bacteria, toxins that decompose into safe products, such as water. Cleaning is carried out under the influence of ultraviolet radiation in a photocatalytic chamber.

Electrostatic filters, which with air ionization and the effects of electric forces are able to remove the smallest pollution particles from the spent masses.

How to choose an air purifier

The design of the ventilation system itself must pass the test for resistance to possible mechanical stresses to which it will be exposed during use. This procedure is extremely important.

In this way, it is ascertained whether the conditions for effective functioning will be created for the filters. This must be done before the start of operation and after making significant design changes.

All filters used must meet a number of conditions. So, during operation, these products should not emit fibers, dust, which can cause damage to people, equipment. That is, any cleaner should be guaranteed to be safe.

Filter Test
Air filters must be tested for compliance.

An important quality is tightness, which eliminates the leakage of contaminated air between the body of the product and its landing frame. Aerodynamic performance must comply with the standards for its class.

Each filter must pass a test for efficiency, compliance with other characteristics, which is necessarily indicated in the product passport or a separate act.

Form an integrated filtration system and initially select the individual components in its composition should be manufacturers, installation organizations, since an outside person will not be able to take into account all the important nuances, which will lead to low efficiency.

Conclusions and useful video on the topic

Information on the design of a popular pocket filter will help to understand what such products are:

A review of the carbon filter will make it possible to understand its features:

Filters are able to remove any contaminants from the air, but for this it is necessary to choose products taking into account the relevant technical characteristics. It should be understood that only filtration systems assembled from several types of cleaners can cope with the tasks set.

To select them, you need to have certain skills, knowledge or seek help from specialists who qualified to carry out the work.

Is there anything to supplement, or have questions about choosing different filters for ventilation? You can leave comments on the publication, participate in discussions and share your own experience in using air purifiers. The contact form is located in the lower block.

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Visitors Comments
  1. Maxim

    At our company, the director put good filters in the ventilation system. I bought it myself, I chose HEPA filters designed for complete cleaning. In summer, dust and poplar fluff do not fly. The only inconvenience of using such filters is that they get clogged up very quickly. Then it becomes clear how much air we breathe, and the filters themselves have to be changed regularly.

    • Expert
      Alexey Dedyulin

      HEPA filters clean microparticles, and cheap filters can handle dust and poplar fluff. But unfortunately, HEPA filters are too expensive to use for ventilation.