As the topic of cabin air quality has garnered more and more attention over the years, it is becoming essential for airlines and operators to be aware of their options.
Advancements in aircraft cabin air filtration have come a long way since it was introduced in the 1980s. Long gone are the "smoking on the plane" days, and transient or nuisance odours can now insight anything from passenger complaints to litigious claims from the flight crew.
Much can be done, though, by upgrading an aircraft's filters. In this article, we will look at the various types of filtration that are available on the market.
Ideally, cabin air quality shouldn't be something your passengers notice. When they do, it can be costly. If you'd like to ensure your cabin air doesn't result in complaints, fill in your information below and a Satair expert will assist you shortly.
High-efficiency particulate air (HEPA) technology has been around since the 1930s and was officially commercialised in the 1950s. Pall Aerospace was the first company to implement these hospital-grade HEPA filters for commercial aircraft in the 1990s.
While HEPA is still highly effective for filtering out bacteria, viruses, fungi and particulates in recirculated cabin-air, it is essential to be aware of some factors and limitations.
According to a briefing paper issued by IATA, HEPA (or True-HEPA) is classified as being able to filter out 99.97% of all harmful or odour-inducing particulates 0.3 microns in size.
These are essentially commercial HEPA knock-offs which don't adhere to the same efficiency standards–with efficiency ratings as low at 80%, in some cases.
In our research, we were unable to find any aviation aftermarket filters with the classification of HEPA-Type. This does not mean that they do not exist, and operators should be aware that HEPA-Type filters do not meet aviation standards.
HEPA can still be considered the gold-standard for filtering out particulates throughout recirculated cabin air. But it is essential to be aware that HEPA filters are limited when it comes to capturing VOC fumes that many come from the engine bleed air.
It is often these fumes which cause the most concern in regards to passenger and flight crew safety. When reported, they can be related to causes of Aerotoxic Syndrome.
Where HEPA filters may come up short is in their ability to filter out noxious odours, due to fume events, activated carbon fills in the gaps. Activated Carbon Filters function by increasing the surface area of a base carbon filter–essentially creating additional pores within its carbon structure. Contaminants and VOC's adhere to these "pores" and lock them in the filter.
"Activated carbon has been proven to be the most economically efficient means of removing VOCs from the air. Anything in the cabin that emits an odour can contribute to cabin odours in the recirculated air," says John Vinson, Pall Product Manager, Americas at Satair.
"This is why activated carbon is the right choice. Not only does it capture odours, but more importantly, VOCs. Specifically, it will favour high-boiling-point VOCs—usually originating from high-temperature environments, such as in the combustion part of an engine—more so than low boiling point VOCs, such as perfumes."
Pall Corporation, the global leader of advanced filtration, separation and purification technologies–and the brand responsible for first introducing medical-grade HEPA filters into the aviation industry–has developed a proprietary filter technology called A-CAF (Advanced Cabin Air Filters).
A-CAF filters combine True-HEPA filtration - to remove microbial contaminants with custom odour - and volatile organic compound (VOC) reduction technology. The technology, in use, has been said to improve cabin air quality by 30%.
The A-CAF product lines are FAA-PMA approved and can replace standard HEPA filters in both Airbus and Boeing models.
"Pall partnered closely with the Aerospace industry to develop these new filter options for Boeing aircraft," explained Steve Simpson, Marketing Director, Pall Aerospace, "Our previous success introducing similar filters for the Airbus A330 and A320 resulted in further demand for A-CAF across the spectrum of commercial aircraft platforms."
*cover image courtesy of Pall Aerospace
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This blog is driven by Satair Marketing & Communication with input from both internal and external contributors.
Satair is a world leading provider of aftermarket services and solutions for the civil aerospace industry. Satair is a stand-alone company and Airbus subsidiary.