January 2025 - Liberty Industries

HEPA vs. ULPA Filters

January 22, 2025 7:04 am Leave a Comment

Depending on your cleanroom setup and filtration needs, you can opt for either a HEPA or ULPA filter. Knowing the differences between ULPA vs. HEPA filters can help you make the right selection for your facility and production process.

What Is a HEPA Filter?

High Efficiency Particulate Air (HEPA) is a specific air filter efficiency standard that certifies filter performance. These filters are capable of capturing up to 99.97% of particulates as small as 0.3 microns. The Institute of Environmental Sciences and Technology’s (IEST) IEST‐RP‐CC034.5 standard and ISO 14644-3 provide detailed guidance for testing HEPA filters.

What Is an ULPA Filter?

Ultra-low Penetration Air (ULPA) is another standard for air filter efficiency that can capture an even higher percentage of particles of sizes even smaller than those that HEPA filters capture. Specifically, ULPA filters capture a minimum of 99.9995% of particles with diameters as small as 0.12 micrometers. Different ULPA filters come with varying most penetrating particle sizes (MPPS), but they’re generally more efficient than HEPA filters.

Part of what makes ULPA filters superior to HEPA filters is their finer mesh and increased fiber density, which work in conjunction to capture much smaller particles during air filtration.

Differences Between HEPA Filters vs. ULPA Filters

While both HEPA and ULPA filters are effective for cleanrooms, there are some key differences between ULPA filters vs. HEPA filters to keep in mind.

Filtration Efficiency

ULPA filters offer more efficiency than HEPA filters, capturing up to 99.9995% of particles down to 0.12 micrometers in size while HEPA filters capture 99.97% of particles down to 0.3 micrometers.

HEPA filters offer sufficient filtration for plenty of facilities, but some cleanroom spaces may need the added efficiency of ULPA filters. For example, cleanrooms may need ULPA filters to meet ISO standards for Class 1 through 5 environments.

Airflow Resistance

The tradeoff of higher-efficiency ULPA filtration is reduced airflow. While both HEPA and ULPA filters affect airflow to a certain degree, ULPA’s finer mesh and denser fibers create more airflow resistance.

In addition to making your HVAC system work harder, the significant airflow resistance of ULPA filters can reduce the number of air changes per hour (ACH). ACH is the number of times per hour that the air in a space is replaced, and cleanrooms generally need to have a high ACH to remain clean. Thus, choosing ULPA filtration requires careful consideration of your production requirements and specific cleanroom space.

Cost and Maintenance

You must also consider the cost of ULPA vs. HEPA filters. Because of their increased efficiency, ULPA filters generally cost up to 30% more than HEPA filters. ULPA filters also don’t last as long as HEPA filters, which can make replacements more frequent and costly in the long run.

Lifespan

ULPA filters generally last around seven to eight years, whereas HEPA filters can last up to 10 years in similar environments.

Applications

The specific cleanroom application for HEPA and ULPA filters depends on the cleanroom’s required ISO Class. Class 1 through 5 cleanrooms require ULPA filters that can meet stricter standards for the following types of processes:

Medical laboratories
Microelectronics manufacturing
Aerospace manufacturing
Semiconductor manufacturing
Pharmaceutical manufacturing

Class 5 through 8 cleanrooms use HEPA filters in the following applications:

Semiconductor research
R&D labs
Media preparation, such as DNA experimentation and cell culture growth
Food and beverage manufacturing

Cleanroom Filters at Liberty Industries

Select between HEPA filters and ULPA filters based on your cleanroom’s specifications and ISO Class. Liberty Industries manufactures and distributes a variety of cleanroom supplies, including ULPA and HEPA filters, modular cleanrooms, laminar flow equipment, and many other products. Whether you need products for an ISO Class 1 to 5 or 6 to 8 cleanroom, we’ll direct you to the right supplies to maintain a consistently clean and efficient production environment.

Archive: Jan 2025