H14 HEPA Filter Unit - High Efficiency Air Purification System from China Suppliers and Factory
Application Area
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Electronics Industry
Semiconductor chip fabrication rooms, LCD panel production lines, precision PCB assembly rooms.
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Pharmaceutical & Bioengineering
Sterile preparation areas, vaccine production lines, Bio safety Laboratories (BSL-2/3), sterile filling lines.
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Healthcare
Hospital operating rooms, sterile wards, ICUs, bone marrow transplant wards.
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Food & Beverage
Aseptic packaging areas, probiotic production zones, dairy product fermentation rooms.
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Scientific Research
Animal laboratories, microbiology labs, precision instrument rooms.
HEPA Unit Structure
- 1 Casing: Usually made of cold-rolled steel plate with powder coating or stainless steel, used to house the filter and the plenum box.
- 2 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 here, ensuring airflow passes uniformly through the entire surface of the high-efficiency filter media, preventing uneven airflow distribution. Velocity Reduction — stabilizes airflow and reduces turbulence.
- 3 High-Efficiency Particulate Air (HEPA) Filter: This is the core component, typically a HEPA filter.
- 4 Diffuser Panel: Installed at the air outlet, usually made of aluminum or plastic. It has regularly arranged holes or slots. Its functions are: 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.
- 5 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
≥ 99.97% Efficiency
For particles ≥ 0.3μm. Industry-standard filtration for cleanrooms, hospitals, and laboratories.
ULPA
≥ 99.999% Efficiency
For particles 0.1–0.2μm. Used in ultra-high standard fields like semiconductors and biosafety 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)
Q What is a HEPA filter unit and how does it work?
A HEPA filter unit is a terminal air purification device used in cleanroom ceilings or walls. It draws in contaminated room air through a fan, passes it through a HEPA or ULPA filter to remove particles ≥ 0.3μm (at ≥ 99.97% efficiency), and then delivers ultra-clean filtered air downward into the controlled environment through a diffuser panel, maintaining the required cleanliness level.
Q 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, making them suitable for most cleanroom, medical, and pharmaceutical applications. ULPA (Ultra-Low Penetration Air) filters offer a higher efficiency of ≥ 99.999% for particles as small as 0.1–0.2μm, and are used in ultra-demanding environments such as semiconductor fabrication and biosafety level laboratories.
Q How long does a HEPA filter last and when should it be replaced?
The service life of a HEPA filter depends on the operating environment, airflow rate, and the level of particulate loading. As dust accumulates, resistance increases. When the resistance reaches an unacceptable threshold — or when there is a risk of captured particles being re-released into the airstream — the filter must be replaced. Regular monitoring of differential pressure across the filter is the most reliable way to determine replacement timing.
Q What industries require HEPA filter units?
HEPA filter units are widely required across multiple industries: Electronics (semiconductor fabs, LCD production, PCB assembly), Pharmaceuticals & Bioengineering (sterile fill lines, vaccine manufacturing, BSL-2/3 labs), Healthcare (operating rooms, ICUs, sterile wards), Food & Beverage (aseptic packaging, dairy fermentation), and Scientific Research (microbiology labs, animal rooms, precision instrument labs).
Q What role does the plenum box play in a HEPA unit?
The plenum box is an empty internal chamber located above the HEPA filter inside the unit casing. It performs two key functions: pressure equalization — converting the velocity pressure from the supply duct into static pressure to ensure uniform airflow distribution across the entire filter face — and velocity reduction, which stabilizes airflow and minimizes turbulence before air passes through the filter media.
Q Can the HEPA filter unit be customized to specific dimensions?
Yes. As noted in the technical parameters, custom sizes are supported to accommodate specific cleanroom ceiling grid configurations or unique installation requirements. The casing can be manufactured from cold-rolled steel with powder coating or stainless steel depending on application needs. Please refer to the technical parameters table for standard sizes and contact us for custom specifications.