Application Introduction of Primary Air Filters

1. Overview

Air filters are core components of ventilation and air purification systems. Their main function is to capture suspended particles in the air (such as dust, pollen, microorganisms, aerosols, etc.) through physical interception, adsorption and other methods, thereby improving indoor air quality, protecting process equipment, or meeting the cleanliness requirements of specific environments.

Primary Air Filters

• Definition and Function:

As the "first line of defense" of the entire filtration system, it mainly undertakes the task of "coarse filtration". It is responsible for filtering larger particles (diameter > 5μm) in the air, such as dust, hair, flying insects, fibers, etc. Its core purpose is to protect downstream medium-efficiency and high-efficiency filters as well as air-conditioning equipment (such as fans, heat exchangers) from being blocked or damaged too quickly by large particles.

• Efficiency Standards:

Generally, it has high efficiency in the weight method, but low filtration efficiency for small particles. According to the internationally accepted MERV standard, it is usually in MERV 1-4; according to the European EN779/ISO 16890 standard, it is mainly aimed at coarse particles.

• Common Materials and Forms:

Materials: Metal mesh, synthetic fibers (e.g., nylon mesh), non-woven fabric, activated carbon filter mesh (with odor removal function).

Forms: Plate type, folded type, bag type (primary bag filter), etc.

• Main Application Scenarios:

Pre-filtration of central air conditioning and fresh air systems in all commercial and civil buildings.

Inlet protection of industrial plants, automobile painting workshops, and large-scale equipment.

Used as pre-filtration for high-efficiency filtration systems such as clean rooms and clean benches.

• Characteristics:

Low air resistance, no impact on system air volume.

High dust holding capacity, able to carry a large amount of dust.

Low cost, requiring regular cleaning or replacement (usually every 1-3 months).