In HVAC systems, in addition to HEPA and ULPA filters, a variety of other types of filters exist to meet the air filtration requirements in different scenarios. Here are some common filter types:
First, the initial effect (crude) filter
Function: The primary filter is mainly suitable for the primary filtration of commercial or industrial ventilation and air conditioning system, or the pre-filtration of clean room ventilation and air conditioning system.
Features: It can filter dust particles with a particle size of more than 5μm, and effectively remove large particle pollutants in the air.
Two, medium effect filter
Function: The filter is mainly used in the air conditioning system of intermediate filtration.
Features: It can filter dust particles with a particle size of more than 1μm, as a front-end filter to protect the next level filter, reduce its load and extend the service life.
Three, sub-high efficiency filter
Function: Sub-high efficiency filter has good performance, which can be used not only as the terminal filter device of ventilation and air-conditioning system in clean rooms, but also as the intermediate filter of ventilation system in places with high cleanliness requirements.
Features: The filtration efficiency is between medium and high efficiency filter, which can effectively remove the small particle pollutants in the air.
Four, gas phase filter
Function: Through chemical and physical adsorption, absorption and catalytic removal of air pollutants (liquid, gas or suspended matter), in order to achieve efficient and rapid air purification requirements.
Application scenario: It is mainly used in hotels, data centers and other commercial places that are sensitive to gas pollution.
Five, activated carbon filter
Function: Activated carbon filter uses the adsorption of activated carbon to remove harmful gases and odors in the air.
Application scenario: It is often used in places where harmful gases such as volatile organic compounds (VOCs) and formaldehyde need to be removed from the air.
6. Other special filters
Electrostatic filter: use electrostatic principle to adsorb particles in the air, with high filtration efficiency.
Wet film filter: It filters dust and microorganisms in the air through a wet film layer. It is often used in air purifiers and humidifiers.
Nano photocatalyst filter: Using photocatalyst technology to decompose harmful substances in the air, such as formaldehyde and benzene, under ultraviolet light irradiation.
Vii. Filters under international standard classification
According to the international standard ISO 16890-2016, filters can also be graded according to ePM efficiency, such as ISO ePM10, ISO ePM2.5, ISO ePM1, respectively, corresponding to the filtration efficiency of particles with different particle sizes.
In summary, there are various types of filters used in HVAC systems, including primary (crude) filters, medium filters, sub-high efficiency filters, gas phase filters, activated carbon filters, and special filters. These filters are unique and suitable for different application scenarios and filtering requirements. When selecting the filter, it should be reasonably matched and selected according to the actual needs and system requirements.