H14 HEPA Filter Unit from China Suppliers | High Efficiency Air Filtration Factory Solutions
Application Area
- Electronics Industry: Semiconductor chip fabrication rooms, LCD panel production lines, precision PCB assembly rooms.
- Pharmaceutical & Bioengineering: Sterile preparation areas, vaccine production lines, Bio Safety Laboratories (BSL-2/3), sterile filling lines.
- Healthcare: Hospital operating rooms, sterile wards, ICUs, bone marrow transplant wards.
- Food & Beverage: Aseptic packaging areas, probiotic production zones, dairy product fermentation rooms.
- Scientific Research: Animal laboratories, microbiology labs, precision instrument rooms.
HEPA Unit Structure
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Casing: Usually made of cold-rolled steel plate with powder coating or stainless steel, used to house the filter and the plenum box.
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Plenum Box: An empty chamber inside the casing, located above the filter. Its functions are: Pressure Equalization — converts velocity pressure from the duct into static pressure, ensuring airflow passes uniformly through the entire surface of the HEPA filter media, preventing uneven airflow distribution. Velocity Reduction — stabilizes airflow and reduces turbulence.
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High-Efficiency Particulate Air (HEPA) Filter: This is the core component, typically a HEPA filter.
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Diffuser Panel: Installed at the air outlet, usually made of aluminum or plastic with regularly arranged holes or slots. Functions include: Further Airflow Equalization — ensures clean air is delivered as vertical laminar flow or uniform turbulent flow. Filter Protection — prevents objects from directly touching the expensive HEPA filter core.
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Damping Layer: Some designs include a perforated plate or damping mesh inside the plenum box to assist with airflow distribution.
The Efficiency of HEPA Filter
🔵 HEPA: Filtering efficiency ≥ 99.97% for particles ≥ 0.3μm.
🟣 ULPA: A higher-grade filter, efficiency ≥ 99.999% (for 0.1–0.2μm particles). Used in ultra-high standard fields like semiconductors and bio safety laboratories.
Service Life of Filters
As dust accumulates on the filter media, the resistance increases. When the resistance reaches an unreasonable level, the filter must be discarded. Sometimes, excessive resistance can cause previously captured dust to become dislodged and re-enter the airflow; when this risk arises, the filter should also be replaced. The resistance of a filter increases with higher airflow rates. By increasing the surface area of the filter media, the relative velocity of air passing through the filter can be reduced, thereby decreasing the resistance.
Product Structure Description
Wind Speed Relationship Diagram
Technical Parameters
Remarks: (1) Initial resistance tolerance of ± 10% (2) Support customer size
Frequently Asked Questions (FAQ)
Q1 What is a HEPA filter unit and how does it work?
A HEPA filter unit is a terminal air-cleaning device installed in cleanroom ceilings or air supply systems. It houses a High-Efficiency Particulate Air (HEPA) filter within a casing and plenum box. Incoming air is first equalized in the plenum box, then forced through the dense HEPA filter media, which captures 99.97% or more of airborne particles ≥ 0.3μm. Clean, filtered air then passes through a diffuser panel and is delivered into the controlled environment as laminar or uniform turbulent flow.
Q2 What is the difference between HEPA and ULPA filters?
HEPA (High-Efficiency Particulate Air) filters achieve a minimum filtration efficiency of 99.97% for particles ≥ 0.3μm and are used in most cleanroom, healthcare, and food-processing applications. ULPA (Ultra-Low Penetration Air) filters offer an even higher efficiency of ≥ 99.999% for particles as small as 0.1–0.2μm. ULPA filters are typically specified for ultra-critical environments such as semiconductor fabrication and biosafety laboratories where even the smallest particles can cause defects or contamination.
Q3 What industries and environments require HEPA filter units?
HEPA filter units are essential in any environment where airborne particle control is critical. Key industries include: Electronics (semiconductor and LCD panel production), Pharmaceuticals and Bioengineering (sterile filling lines, BSL-2/3 labs), Healthcare (operating rooms, ICUs, bone marrow transplant wards), Food and Beverage (aseptic packaging, dairy fermentation rooms), and Scientific Research (microbiology labs, animal facilities, precision instrument rooms).
Q4 How long does a HEPA filter unit last, and when should it be replaced?
The service life of a HEPA filter unit depends on the operating environment, airflow rate, and dust load. As dust accumulates on the filter media, airflow resistance increases. The filter should be replaced when resistance reaches an unacceptable level — typically beyond the design threshold — or if there is any risk that trapped particles may dislodge and re-enter the airstream. Increasing the filter media surface area can help reduce airflow velocity and extend service life by slowing the rate of resistance build-up.
Q5 What is the role of the plenum box in a HEPA filter unit?
The plenum box is an internal chamber located above the HEPA filter inside the unit casing. It serves two key functions: first, it converts velocity pressure from the supply duct into static pressure (pressure equalization), ensuring that airflow is distributed uniformly across the entire surface of the filter media rather than concentrated in one area. Second, it reduces airflow velocity and turbulence before the air reaches the filter, stabilizing the airflow and improving overall filtration performance and efficiency.
Q6 Can HEPA filter units be customized to fit specific installation requirements?
Yes. HEPA filter units can be manufactured in custom sizes to meet specific installation and application requirements. The casing is available in cold-rolled steel with powder coating or stainless steel to suit different environments. Custom dimensions are supported, as noted in the technical parameters. Initial resistance tolerance is ± 10%. Please contact our team with your specific requirements for a tailored solution.