In the search for cleaner indoor air, many industries face the challenge of maintaining optimal air quality within their facilities. One effective solution is incorporating a dust collection system equipped with a High Efficiency Particulate Air (HEPA) after-filter. Let’s review some of the most frequent questions regarding this type of filter.

Question: How Is a HEPA filter made?
Answer: HEPA filters are made from polyester, polypropylene, or fiberglass fibers that are tightly interlaced with diameters of less than one micron. The fibers are twisted, turned, scattered, and randomly placed in different directions to create a mesh maze without a straight through path. The openings between the fibers are smaller than a half micron, which is why HEPA filters can catch particles smaller than 0.3 microns.
Question: How Does a HEPA After-Filter Work?
Answer: When a dust collector draws in dirty air and dust particles, the primary filters capture larger particles while allowing cleaner air to pass through. However, ultrafine particulates may still escape through the primary filters. Here’s where the HEPA after-filter comes into play. Positioned on the clean air side of the unit, the HEPA after-filter acts as a secondary filtration stage, capturing even the tiniest microscopic particles before the air is returned to the facility.

Question: How is a HEPA filter different from regular filters?
Answer: The main difference between a HEPA filter is that it is made of thin fibers of glass and activated carbon-based materials. Regular filters are made of porous materials like cotton, paper sheets or polyester. Most importantly, HEPA filters offer much higher filtration efficiency (MERV 16 or higher) compared to a standard fabric filter.
Question: When Do I Need a HEPA After-Filter?
Answer: Consider incorporating a HEPA after-filter in the following scenarios:
- — If your process generates fine particles that pose health risks or can contaminate products.
- — When regulatory or industry standards demand exceptionally high air quality.
- — If the collected dust contains hazardous materials, allergens, or carcinogens.
- — When you aim to recirculate filtered air back into the facility, necessitating cleaner air to improve indoor air quality.
Question: Does a HEPA After-Filter Help Against COVID-19?
Answer: Yes. By incorporating a HEPA after-filter into your dust collection system, you can significantly reduce the risk of airborne transmission of the virus within your facility. While other safety measures like social distancing and mask-wearing are essential, purifying the air with a HEPA filter adds an extra layer of protection.

Question: What Does it Cost to Add a HEPA After-Filter?
Answer: First, the size and quantity of HEPA filters for your system will depend on the airflow of your system. Each HEPA filter is sized for a specific airflow, and multiple filters may be required to meet the required airflow and static pressure requirements of your system. Once the quantity, size, and type of HEPA filter is determined, a HEPA filter housing is needed to house the filters, along with ductwork to connect your HEPA filters to your existing dust collection system, and route clean air to the desired location. A Baghouse.com dust collection specialist can help you size and spec out a HEPA after-filter and provide a quote for your project.
In conclusion, a HEPA after-filter serves as a powerful ally in the ongoing battle for cleaner indoor air quality, particularly in industrial settings. Baghouse.com can provide expert guidance in selecting the right HEPA filter and offer comprehensive support from installation to maintenance.
Do you have any additional questions regarding the HEPA filters? Contact us today to discover how we can enhance your dust collection system with HEPA filtration.
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