Filtech Testing Division - HEPA Filter Leak Testing

Leak Testing for HEPA Filters and HEPA/ULPA Filters

Leak testing is a critical quality control process for High Efficiency Particulate Air (HEPA) and Ultra-Low Penetration Air (ULPA) filters, ensuring their integrity and effectiveness in various controlled environments. At Filtech, we employ advanced equipment and methods to conduct precise leak testing, ensuring that every bit of air meets the high standards expected from these filters.

Particle Size Matters: 0.3 Microns and HEPA Filter Efficiency

Understanding the significance of 0.3 microns in leak testing is crucial. This particle size is considered the most penetrable and challenging for HEPA filters to capture. Therefore, it serves as a critical test particle size to determine a filter's efficiency rating. Filtech utilizes a Tec Services PH5 Aerosol Photometer paired with an Aerosol Generator that emits 0.3-micron smoke particles to assess HEPA filter performance.

Why 0.3 Microns?

· Most Challenging: 0.3-micron particles are among the most difficult for HEPA filters to capture, making them an excellent indicator of filter efficiency.

· Worst-Case Scenario: Testing at this particle size ensures that even the smallest potential leaks are detected, guaranteeing the highest level of safety.

Pinhole-Sized Leak Detection

Our advanced equipment and expertise allow us to pinpoint even the tiniest pinhole-sized leaks in HEPA and ULPA filters with precision. This meticulous approach ensures that no leaks go unnoticed, maintaining the integrity of your controlled environment.

HEPA Filter Repairs and Patching

In the event of a detected leak, Filtech's technicians are well-equipped to provide expert HEPA and ULPA filter repairs. We utilize DOW RTV sealant to patch any holes, ensuring that the filter meets the necessary standards and remains in optimal working condition.

Test Procedures as per NSF Standards

The leak testing procedures employed by Filtech adhere to NSF/ANSI 49-2020 standards. Here is an overview of the methods involved:

Methods for Testing HEPA/ULPA Filters:

1. Filters That Can Be Scanned: These filters are assessed by introducing an aerosol into the cabinet and scanning the downstream side of the filter with a photometer probe. Reported values include upstream aerosol challenge concentration, maximum leak penetration, method used for reporting concentration, testing method (scanned or probe tested), and the test name (HEPA/ULPA filter leak test).

2. Filters That Cannot Be Scanned: In cases where exhaust filters cannot be scanned, a hole is drilled in the duct downstream, and the photometer probe is inserted for testing. Reported values include upstream aerosol challenge concentration, maximum leak penetration, method used for reporting concentration, testing method (scanned or probe tested), and the test name (HEPA/ULPA filter leak test).

Acceptance Criteria

HEPA/ULPA filters are rigorously tested against acceptance criteria to ensure their effectiveness:

· Filters That Can Be Scanned: Sustained aerosol penetration must not exceed 0.01% of the upstream concentration at any point.

· Filters That Cannot Be Scanned: Sustained aerosol penetration must not exceed 0.005% of the upstream concentration.

Establishing and Maintaining Filter Efficiency

Leak testing contributes significantly to establishing and maintaining the efficiency of HEPA and ULPA filters. HEPA filters are known for their exceptional efficiency in capturing and retaining particles as small as 0.3 microns, with a 99.97% efficiency rating. However, even the tiniest hole or defect in a HEPA filter's structure can compromise its performance.

By conducting rigorous leak tests, we verify the integrity of the filter, ensuring it is free from leaks or defects. Regulatory bodies, such as the National Sanitation Foundation (NSF), have established strict standards for HEPA filters, including specific criteria for filter integrity and leak rates. HEPA filters must meet these criteria to be considered efficient. Leak testing helps demonstrate compliance with these standards, reinforcing the filter's efficiency rating.

Performance Assurance

The 99.97% efficiency rating of HEPA filters is based on their ability to capture and retain particles with a very high level of efficiency. Leak testing identifies and addresses any issues that could compromise this performance. By ensuring that the filter is free from leaks, we guarantee that it performs at or near its rated efficiency.

Preventing Contamination

In critical environments like cleanrooms, laboratories, and healthcare facilities, maintaining a sterile and contaminant-free atmosphere is paramount. HEPA and ULPA filters play a crucial role in achieving this goal. Leak testing helps prevent potential contamination by ensuring that the filter effectively captures and retains particles, pathogens, and contaminants.

Long-Term Efficiency

HEPA and ULPA filters may experience wear and tear over time, or they may be subjected to physical damage during installation or maintenance. Regular leak testing as part of routine maintenance identifies any issues that could impact the filter's efficiency. Addressing these issues promptly extends the filter's lifespan and maintains its high efficiency rating.

Ensuring Efficiency

Leak testing is an essential step in quality control, ensuring that HEPA and ULPA filters perform at or near their specified 99.97% efficiency. It contributes to maintaining a clean and controlled environment while upholding compliance with industry standards.

At Filtech, we are committed to the integrity and efficiency of your HEPA and ULPA filters. For comprehensive leak testing services and HEPA filter repairs, contact us today. Ensure the efficiency and performance of your critical environments with Filtech.