Application Introduction of High-Efficiency Air Filters

High-Efficiency Air Filters

Definition & Functions

As the ultimate gatekeeper of filtration systems, high-efficiency air filters deliver the finest level of filtration. They are primarily designed to capture submicron-sized particles (diameter < 1μm), including smoke, viruses, radioactive aerosols, asbestos and all other solid and gaseous particulates. Their filtration efficiency for particles ≥ 0.3μm is no less than 99.97%.

Efficiency Standards

The EN1822 standard is commonly adopted, which classifies high-efficiency filters into two categories: HEPA and ULPA.

HEPA: Filtration efficiency ≥ 99.97% for 0.3μm particles (e.g., H13 grade).

ULPA: Filtration efficiency ≥ 99.999% for 0.1–0.2μm particles (U15 grade and above), offering higher efficiency than HEPA filters.

Common Materials & Types

Materials

The filter media are mainly made of ultra-fine glass fiber filter paper.

Types

Separated type: Ensures unobstructed airflow channels.

Separless type: Features smaller volume and higher filtration efficiency.

The outer frame is usually made of wood or metal (e.g., aluminum profiles, stainless steel), and equipped with sealing strips to ensure zero leakage.

Main Application Scenarios

1. Clean rooms: Electronic chip manufacturing, biopharmaceuticals, sterile operating rooms, and laboratories.

2. Hospitals: Operating rooms, ICU wards, and negative-pressure isolation wards.

3. High-end manufacturing: Aerospace industry and precision instrument production.

4. Civil/commercial use: High-end air purifiers, haze-proof fresh air systems, and ventilation systems in nuclear power plants.

Features

Extremely high filtration efficiency, with relatively high air resistance.

Relatively low dust holding capacity, requiring robust pre-filtration protection at the front end of the system.

High cost. Once installed, it should not be disassembled unless necessary, and replacement is only required when the final resistance reaches the set value (usually every 1–5 years, depending on the condition of front-end pre-filtration).

Proper filter selection and combination are the key to ensuring system performance and cost-effectiveness. High-efficiency air filters are not required for all scenarios, but any system relying on high-efficiency filters must be equipped with primary and medium-efficiency filters as front-end protection.

Regular maintenance and replacement are essential to guarantee filtration performance and stable system operation. Neglecting the replacement of primary and medium-efficiency filters will lead to premature failure of high-efficiency filters, resulting in substantial economic losses.