HEPA filters
HEPA filters (High Efficiency Particulate Air filters) are the main components of advanced air filtration devices engineered to capture extremely small (fine) particles, down to one micron (µm), or one-millionth of a meter. These filters meet stringent standards for removing pollutants, even the tiniest of these particles.
HEPA Ceiling Filters
HEPA ceiling filters ensure a leak-proof design that offers superior performance and durability. Applications: final filter for cleanrooms and Laminar Air Flow (LAF) units, life science, healthcare, microelectronics, food & beverage. Characteristics: high quality glass fibre media, guaranteed leak free, individual test certificate (acc. to EN 1822 – ISO 29463).
HEPA Panel Filters Versatile
HEPA panel filters are used in various applications, some of them as final filters for HVAC and cleanrooms. Some of the characteristics are simple and lightweight, frame depth in various dimensions starting from only 32 mm, tested and certified acc. to EN 1822 – ISO 29463.
HEPA High Capacity Filters with Single Pleat and with V Module Design
High Capacity HEPA Filters with Single Pleat and with V Module Design are often used as final filters for AHUs, in life science, healthcare, operating theatre LAF units, food & beverage. Some of the characteristics are high airflow rates (2000 – 4000 m3/h for 610x601x292 mm), high quality glass fibre media, guaranteed leak free, tested and certified acc. to EN 1822 – ISO 29463.
HEPA V-Compact Filters
HEPA V-Compact filters are often used as final filters for HVAC and cleanrooms, in gas turbine air intake systems. Some of the characteristics are large filtration area, simple and lightweight, low initial pressure drop, tested and certified acc. to EN 1822 – ISO 29463.
HEPA Filters with Aluminium Separator
HEPA filters with aluminium separators are usually used as final filters for AHUs under high temperature conditions. Some of the characteristics are temperature resistance up to 120 °C and 260 °C, static electricity grounding cable available on request, corrugated aluminium separator, guaranteed leak free, tested and certified acc. to EN 1822 – ISO 29463.
HEPA Cylindrical Filters
HEPA cylindrical filters are often used in pharmaceutical and biotechnology industries, and in life science. Some of the characteristics are compact construction, suitability for limited space, customizable cover design on request, flexibility in dimensions as many are available.
HEPA filter applications
HEPA (high efficiency particulate air) filter, also known as a high efficiency particulate arresting filter, is an efficiency standard of air filters.Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove, from the air that passes through, at least 99.95% (ISO, European Standard) or 99.97% (ASME, U.S. DOE) of particle whose diameter is equal to 0.3 µm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm. HEPA filters capture pollen, dirt, dust, moisture, bacteria (0,2 – 2,0 μm), viruses (0,02 – 0,3 μm), and submicron liquid aerosol (0,02–0,5 μm). Some microorganisms, for example, Aspergillus niger, Penicillum citrinum, Staphyococcuc epidermidis and Bacillus subtilis are captured by HEPA filters with photocatalytic oxidation (PCO). A HEPA filter is also able to capture some viruses and bacteria which are ≤ 0,3 μm. A HEPA filter is also able to capture floor dust which contains bacteroidia, clostridia and bacilli. HEPA was commercialized in the 1950s, and the original term became a registered trademark and later a generic trademark for highly efficient filters. HEPA filters are used in applications that require contamination control, such as the manufacturing of hard disk drives, medical devices, semiconductors, nuclear, food and pharmaceutical products, as well as in hospitals, homes, and vehicles.
HEPA filter construction
HEPA filters are made from polyester, polypropylene, or fiberglass fibres that are tightly interlaced with diameters of less than one micron. The fibres are twisted, turned, scattered, and randomly placed in different directions to create a mesh maze without a straight true path. The spaces between the fibres in a HEPA filter are smaller than half a micron, allowing the filter to capture particles smaller than 0,3 microns.
The frame of a HEPA filter can be made from a variety of materials. For ones being used for industrial and manufacturing operations, the frames are normally made of tough, resilient, and durable materials such as carbon steel, aluminium, stainless steel, or galvanized steel. The size of the frame must be carefully planned since its resistance to the airstream can increase the pressure drop.
Choosing the right adhesive for HEPA filter construction is crucial to ensure it does not impact the filter’s performance. The adhesive must stay in place without migrating into the fibre material. Common adhesives for HEPA filters include polyurethane, silicone, and ceramic.
Gaskets play a critical role in the performance of a HEPA filter and can be made from die cut urethane rubber and closed cell sponge rubber. The choice of rubber as a gasketing material is more economical and easier to install than liquid silicone systems. Gaskets are precisely cut from sheets or rolls to ensure they fit the required shape. Gasket shapes include strip, one-piece, and interlocking designs, with interlocking being the most cost-effective and easiest to install. Gaskets are affixed to the frame using solvent-activated or pressure-sensitive adhesives. The joints are sealed with RTV materials compatible with closed-cell rubbers. The most used gasket type is die-cut, which is attached to the outer edge of the frame and pressed against a flat surface. All HEPA filter gaskets are resistant to oil and ozone.
Gel-Seal is a unique, ice-blue silicone gel specifically designed to create and preserve an airtight seal between high-efficiency particulate air filters and their holding frames or housings. The gel is factory-installed and factory-cured in the perimeter channels of filters designed for fluid seal applications. The cured gel has the self-healing qualities of a liquid while retaining the stability and non-flow characteristics of a solid. These properties are maintained at both high and low temperature extremes and are not lost even when aged continuously at high temperatures. Gel-Seal exhibits excellent bonding characteristics to many materials, it is also highly self-adhesive, allowing knife edges and filter skirts to be cleanly withdrawn. The hydrophobic nature of the gel makes it ideally suited for applications that require long-term sealing against moisture and other atmospheric contaminants.
HEPA filter standards
European Standard EN 1822-1:2019, from which ISO 29463 is derived, defines several classes of filters by their retention at the given most penetrating particle size (MPPS): Efficient Particulate Air filters (EPA), High Efficiency Particulate Air filters (HEPA), and Ultra Low Particulate Air filters (ULPA). The averaged efficiency of the filter is called “overall”, and the efficiency at a specific point is called “local”.
Frequently asked questions about HEPA air filters
What is HEPA filter?
HEPA (High Efficiency Particulate Air) filter is a type of air filter designed to trap airborne particles, including dust, pollen, mould, bacteria, and viruses, with a high degree of efficiency. It’s certified to capture at least 99.97% of particles down to 0.3 microns in size, which is the most penetrating particle size.
Which are the key features of HEPA filters?
- HEPA filters are known for their ability to remove a high percentage of airborne particles, including those that are very small.
- They trap particles by filtering air through a pleated mesh of thin fibres, typically made of glass or borosilicate.
- HEPA filters are used in various applications, including air purifiers, vacuum cleaners, and specialized environments like hospitals and cleanrooms.
- HEPA filters require regular replacement to maintain their effectiveness.
What are the benefits of using HEPA filters?
- HEPA filters can remove harmful particles from the air, leading to cleaner and healthier indoor air.
- By removing allergens and irritants, HEPA filters can help alleviate symptoms of allergies and asthma.
- HEPA filters can capture bacteria and viruses, reducing the risk of airborne infections.
What diseases are associated with exposure to air pollution?
What are some of the most important air pollutants leading to disease?
Although there are many toxins that have adverse impacts on health, pollutants with the strongest evidence for public health concern include particulate matter (PM), carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2) and sulphur dioxide (SO2). Fine particulate matter is an especially important source of health risks, as these very small particles can penetrate deep into the lungs, enter the bloodstream, and travel to organs causing systemic damages to tissues and cells.
What does depth loading vs. face loading mean and what is the advantage to each?
Depth loading a filter refers to a filter of various density. Initially the looser matrix of fibres will catch only the large particles, allowing the smaller particles to pass. As the matrix of fibres becomes more tight than smaller particles will be caught. The advantage to a depth loading filter is the amount of dust holding capacity.
A face loading filter will capture all the particles on the media. These filters are designed to fill up fast with particles, but their advantage is they can be cleaned easily. In many dust collectors with self-cleaning or pulsing mechanisms they will get a blast of air from the clean side and the particles will fall into a collection hopper.Filter sa površinskim zaprljanjem će hvatati sve čestice na površini medijuma. Ovi filteri su dizajnirani da im se površina brzo zaprlja česticama, ali njihova prednost je što se taj površinski sloj može lako očistiti. Koriste se kod kolektora prašine, sa mehanizmom za samočišćenje pomoću pulsiranja mlaza komprimovanog vazduha sa čiste strane medijuma, kada čestice spadaju u sakupljački levak otprašivača.
What are HEPA, ULPA, SULPA and Ultimate ULPA filters?
HEPA (High Efficiency Particulate Air) filter has a minimum particle collection efficiency of 99.97% for particles 0.3 microns in diameter.
ULPA (Ultra Low Penetration Air) filter has an efficiency of 99.999% for particles in the most penetrating particle size at the specified media velocity. The most penetrating particle size is the particle diameter that penetrates most through the filter media.
SULPA (Super ULPA) filter has an efficiency of 99.9999%, these filters are based on the same standard as the ULPA filters.
Ultimate ULPA filter has an efficiency of 99.9999999%, these filters are based on the same standard as the ULPA filters.