What is a HEPA filter?

A High-Efficiency Particulate Air (HEPA) filter is any filter which is capable of removing 99.97% of particles that are the size of 0.3 of a micron. This standard was established by the U.S. Dept. of Energy, and later widely adopted as an international standard, the European EN1822. Under the EN1822, there are 8 different filter classes in order from least to most efficient. Classes E10 to E12 are Efficient Particulate Air (EPA) filters, H13 and H14 are HEPA filters, and U15 to U17 are Ultra Low Penetration Air (ULPA) filters¹.

Around the home, you may recognize their use in air purifiers and vacuums. They are widely used industrial, medical, and manufacturing environments where dust and other potentially harmful and undesireable particulates are present. However, they come at a considerable cost compared to most conventional filters, and while offering numerous benefits over conventional filters, it is important to know when and where it is appropriate to use them over a conventional filter.

Let’s dive in and learn a bit about HEPA filters.

Table of Contents

What is a HEPA Filter?

Development of HEPA Filtration

The origins of HEPA filtration can be traced back to the early 1940s during World War II. As the need to protect scientists working on the Manhattan Project from radioactive particles led to the creation of highly efficient filters. Scientists at the U.S. Atomic Energy Commission developed the first HEPA filters that were were originally known as “absolute filters”. Consequently, the development of these filters would provide a level of protection essential to maintain a safe working environment as well as offering a level of air purity and overall cleanliness that would otherwise be unobtainable.

As HEPA filter technology evolved, improvements in filter media materials, manufacturing techniques, and testing standards contributed to their increased efficiency and reliability. In addition, standardization by organizations like the Institute of Environmental Sciences and Technology (IEST) and the U.S Department of Energy (DOE) helped establish rigorous testing protocols and classifications for HEPA filters, ensuring their quality and performance.

Benefits Over Conventional Filters

HEPA filters offer several advantages over conventional filters, making them the preferred choice in many applications:

1. Superior Particle Capture: HEPA filters can capture particles as small as 0.3 microns with an efficiency of 99.97%. This is significantly better than most conventional filters. This high level of filtration is crucial in environments where air quality is critical.
2. Allergen and Pathogen Removal: HEPA filters excel in removing allergens, dust mites, pollen, pet dander, and even bacteria and viruses from the air. This capability makes them essential in medical facilities, homes of allergy sufferers, and during disease outbreaks.
3. Clean room Applications: HEPA filters are vital in clean rooms used in industries such as pharmaceuticals, electronics, and aerospace. They help maintain the sterile and particle-free environments required for precision manufacturing and research.
4. Improved Indoor Air Quality: HEPA filters enhance indoor air quality by removing pollutants, odors, and contaminants. As a result, a healthier and more comfortable living or working environment.
5. Longevity and Durability: HEPA filters are known for their durability and longevity. They compared to conventional filters, reducing long term maintenance costs. While HEPA filters often have a higher upfront cost, they require less frequent replacement. Their efficiency, and durability will offset the cost of using conventional filters long term.
6. Compliance with Standards: HEPA filters adhere to strict standards and regulations, ensuring consistent performance and reliability.

Uses of HEPA Filters

HEPA filters find applications in a wide range of industries and settings due to their exceptional filtration capabilities:

1. Medical Facilities: HEPA filters are used in hospitals, clinics, and laboratories to maintain sterile environments, prevent the spread of infectious diseases, and protect patients and healthcare workers.
2. Residential Air Purifiers: Home air purifiers equipped with HEPA filters are effective at removing allergens, dust, and pollutants, improving the air quality in living spaces.
3. HVAC Systems: HEPA filters in HVAC systems enhance indoor air quality by trapping airborne contaminants, preventing them from circulating through buildings.
4. Aerospace and Electronics: Clean rooms in aerospace and electronics manufacturing use HEPA filters to maintain particle-free environments, preventing damage to sensitive components.
5. Pharmaceutical Industry: HEPA filters are crucial in pharmaceutical manufacturing to ensure the quality and sterility of drugs and medical products.
6. Nuclear Facilities: HEPA filters are used in nuclear facilities to capture radioactive particles and protect workers from radiation exposure.

When to Use a HEPA filter over a conventional one

The decision to use HEPA filters over conventional filters depends on specific requirements and the environment. It’s useful to consider the following when deciding when to use them:

1. Allergen Sensitivity: Individuals with allergies or respiratory conditions benefit from HEPA filters, which can effectively remove allergens from the air. Conventional filters may fall short of the needs of individuals with sensitive respiratory systems or severe allergies. A HEPA filter may provide the added filtration necessary to meet their needs.
2. Medical Settings: In healthcare settings and during disease outbreaks, HEPA filters are essential to prevent the spread of airborne pathogens.
3. Precision Manufacturing: Industries like electronics and pharmaceuticals require HEPA filters to maintain clean room environments and protect sensitive equipment.
4. High-Contaminant Environments: Use HEPA filters in environments with a high concentration of particles or pollutants like during times of construction around the home or office, and in urban settings.
5. Improved Indoor Air Quality: Using HEPA filters in air purifiers, vacuum cleaners, or HVAC systems will help reduce dust and allergen levels. This improves indoor air quality, and reduces the amount of time you spend cleaning and dusting.

Where do I get HEPA filters?

Although HEPA filters are a more specialized type of filter, they’re usually available in many industry standard filter sizes. Big box stores, as well as your local hardware store may even carry them many common sizes. When in doubt, consult the operators manual of your piece of equipment for replacement part numbers or air filter dimensions. Keep a measuring tape handy if you need to search for filters by size.