Picture: Close-up of fiberglass in a HEPA 14 filter, enlarged 4000 times.
HEPA 14, also called H14, is the filter class commonly used to filter out bacteria, viruses, and other airborne contaminants in sensitive healthcare environments. In this article, we’ll take a closer look at the filter classification and how it is used in QleanAir solutions.
What does HEPA mean?
HEPA is an abbreviation of High-Efficiency Particulate Air. It is a series of highly efficient filters, classified according to standard EN 1822 for particulate filters. The filters are divided into different classes depending on how good they are at filtering out the particle size that is most difficult to capture, called MPPS (Most Penetrating Particle Size).
HEPA 14 filters in healthcare environments
HEPA filters are divided into two classes: HEPA 13 and 14. HEPA 14 is the filter commonly used in environments that are particularly sensitive to airborne particles, e.g. healthcare environments and laboratories.
All HEPA 14 filters are tested individually and have at least 99.995% filtration efficiency for 0.1–0.2 µm particles*. It is the particle size that is most difficult to capture. For larger as well as smaller particles, the filter has even higher filtration efficiency.
The influenza B virus is estimated to be about 0.12 μm and the new coronavirus at most, 0.16 μm. They may for some time be encapsulated in the droplets (about 10 μm) that spread in the air when we cough and sneeze as well as in the aerosols (about 1 μm) in our exhaled air. A single breath can contain anywhere from 1,000 up to 50,000 microdroplets.
While the droplets are in the air for a certain period of time, it is difficult to know for how long, how far they can move, and how much is needed to pose a risk of infection. The microdroplets are also affected by air temperature, humidity, and movements (air flows). Here you can read more about droplet contamination and aerosols.
What filters does QleanAir use?
QleanAir's air purification solutions have multistage filtration, which means that there are always at least two filters. For several of our products, e.g. QleanAir FS 70, the filter composition varies between different customers. Together with the customer, we get to know the environment. By doing so, we identify sources that degrade air quality, define the goal of the air purification solution, and then put together the solution that gives the best results in the specific environment.
For particle filtration, we use EPA filters (EPA 10 or 12) or HEPA filters (HEPA 14) according to standard EN 1822, or ePM1 (60 or 80%) according to standard ISO 16890.
EPA 10: Minimum separation efficiency 85%
EPA 12: Minimum separation efficiency 99.5%
HEPA 14: Minimum separation efficiency 99.995%
Air purifiers that are placed in very sensitive environments have HEPA 14 as the main filter. It is also what is used as particle filters in our smoking cabins, along with multiple layers of carbon filters. EPA filters are used, among other things, in food production, where hygiene requirements are high but HEPA filters are not necessary. ePM1 filters are mainly used in industrial environments.
QleanAir FS 70 HEPA
QleanAir FS 70 HEPA is an air purifier designed to be placed in healthcare environments with requirements for HEPA 14 filtration. It delivers high purity and air circulation (up to 3000 m3 per hour) without disturbing the comfort of staff and patients. The product page contains more detailed information on FS 70 HEPA and how it is used in healthcare.
Why are HEPA filters not always used?
Higher filtration rate means more advanced filters, thus having a higher cost. Also, the higher the filtration rate of a filter, the lower the dust retention capacity. A finer filter can collect less dust before it becomes full and must be replaced. If there is no need for HEPA filtration, it becomes an unnecessary cost to the customer. We always offer a customized solution that is configured according to the desired result, but which is also as cost and energy-efficient as possible.