Types of primary air filters

The primary filter is the primary filtration for air conditioning systems and is mainly used to filter dust particles above 5μm.
There are three types of primary filters: panel, folding, and bag.
The outer frame material is a paper frame, aluminum frame, or galvanized iron frame, the filter material is non-woven fabric, nylon mesh, activated carbon filter material, metal hole mesh, etc.
The protective mesh is double-sided sprayed wire mesh and double-sided galvanized wire mesh.

The primary air filter belongs to G series coarse air filter classification, divided into eight varieties, namely: G1, G2, G3, G4, GN (nylon mesh filter), GH (metal mesh filter), GC (activated carbon filter), GT (high temperature resistant coarse air filter).

Primary air filters are generally used for pre-filtration and secondary filtration of air conditioning and ventilation systems, clean room air intake or return air filtration, etc.

The primary filter is used to filter dust particles above 5um, mainly to protect the next filter section of the medium efficiency filter.
There are several styles of primary air filters, such as folding, plate, bag, etc.
The outer frame is often made of aluminum, galvanized frame, or paper frame, and the filter material is non-woven, activated carbon filter material, metal pore mesh, etc.
Due to factors such as good versatility, lightweight and low price, primary filters are widely used in the pre-filtration of ventilation systems.


Primary air filter plate bag style classification:

1. Plate-type primary air filter


The filter efficiency is available in G2, G3, G4, F5 (EN779), etc.
It has the characteristics of large air volume, small resistance, high dust capacity, easy installation, and long service life.
It can be used in the ventilation system of general industrial plants, and also in the pre-filtration of air conditioning systems and ventilation systems.

2. Folded primary air filter

Folded primary air filters can withstand humidity up to 99% and temperatures up to 80 degrees Celsius, generally used for pre-filtration and secondary filtration of air conditioning and ventilation systems, clean room air inlet, or return air filtration.
The outer frame is usually made of aluminum alloy, which is light in quality, easy to install, and has a beautiful and clean appearance.
The disassembled design makes it easy to replace the filter media to achieve the purpose of reuse of the frame.
The filter material is 15mm or 20mm thick primary filter cotton, made of high-quality polyester synthetic fiber, with high dust-holding capacity and low resistance. The internal frame is designed with inner frame compression or bonding technology to ensure the hermeticity of the filter and prevent leakage.
Due to the folding process, the filtering area is 3 times larger than that of ordinary flat filters and the filtration is more thorough.

3. Bag-type primary air filter

High-quality non-woven fabric is used as the filter material of the filter bag, with low initial resistance, good filtration, large dust capacity, and long service life.
The filter bags are fixed with metal strips and nails to increase the strength of the filter network, with a strong structure, not easy to leak and rupture, and improve the filtration efficiency.
At the same time, the outer frame is fixed with a solid galvanized frame with metal strips, which is strong and stable, so that the air filter will not be deformed and damaged in a poor environment.


Structure of the primary plate filter


The primary panel filter is mainly composed of a protective mesh, filter media, and an outer frame.
Each part is made of a different material.
The outer frame of the filter is generally made of paper, aluminum, and galvanized iron.
The filter material of the primary panel filter is non-woven, nylon mesh, activated carbon filter material, metal perforated mesh, etc.
These filter materials are packed into cardboard in the form of folding, and the dust particles in the inflowing air are blocked by the filter material between the pleats, and the clean air flows out evenly from the other side.


Different types of primary filters are used for different purposes


1. Polyester fiber panel filter is mainly used for filtering dust particles in the air, which is the material commonly used for primary filters.

2. Polypropylene fiber panel filter is what we often call a nylon mesh filter, which has the feature of repeated washing without reducing the filtering efficiency.

3. Glass fiber panel filter is mainly used for air filtration in a high-temperature environment, which can withstand high temperatures up to 350° C, generally known as high-temperature filter.

4. Activated carbon fiber is mainly used to adsorb odor and toxic and harmful substances in the air, generally known as an activated carbon filter.