The Importance of Air Filtration

CLEAN AIR FILTRATION "VITAL FOR INDUSTRY", CAMFIL PRESIDENT WARNS

Industry Europe Speaks With Don Donovan Of Camfil About How Industry Can Best Use Filtration To Tackle Air Pollution.

The coronavirus pandemic has brought several issues into the public consciousness, but none may be as important as the battle against air pollution in industry's perpetual struggle to lower CO2 and greenhouse gas emissions.

According to the UN's Environment Programme, the construction sector alone saw a 2% increase in carbon emissions from 2017 to 2018 and reached its peak in 2019, accounting for 38% of total global CO2 emissions.

The sector offers many ways, such as the production of cement, the construction or demolition of buildings and the operation of heavy machinery, to emit pollutants into the atmosphere.

Air pollution has been linked with numerous health effects, such as respiratory problems, cardiovascular diseases and lung cancer.

The International Energy Agency (IEA) estimates that direct building carbon emissions need to decrease by 50% by 2030 - 6% per year - to have a chance of meeting global energy targets.

According to the report, most countries have yet to submit their Nationally Determined Contribution targets (NDCs), with the building sector lacking any specific mitigation policies, despite its huge contribution to CO2 emissions.

However, the social distancing guidelines, the increased focus on ventilation and filtration alongside an environment for infection brought on by the pandemic seems to have had a knock-on effect. "Before the pandemic, air filtration was not on everyone's lips," Don Donovan, the European President of Camfil said in an interview with Industry Europe. "Now, with the rise of an airborne virus, everyone wants good air filtration and good systems in place to minimise the spread and I can see this trend continuing as the world leaves the pandemic behind it." "With Covid, governments have been pushed to ensure cleaner air for the public, whereas before much of the legislation towards air issues primarily tackled pollution or emissions."

Air pollution comes in two major flavours: gases and particulate matter, and they can be present in both man-made and environmental emitters. Donovan points to pollen as a classic example of an environmental form of air pollution that can affect people.

However, "man-made" air pollution generally comes in the form of dust or greenhouse gases, or even odours, he added. Heavy industry, in particular, has become notorious for the volumes of particulate matter and gases it releases into the atmosphere.

Particulate matter can come in various forms. One common example is the spore aspergillus, which can be present when knocking down old buildings.

While normally harmless, those with weakened immune systems or existing respiratory problems may suffer from lung infections, according to the Mayo Clinic. Some strains may even spread into the bloodstream.

Aspergillus spores can be found in various climates worldwide and many people breathe in the spores daily without falling ill. "The processes by which the construction sector runs can release gases, odours and heavy dust or any other kind of matter into the atmosphere," Donovan said. "The way this can be controlled from an air filtration point-of-view is by either filtering and collecting the particles, or, in the case of gases and odours, by running it through an abatement system - a carbon air filter - which absorbs it." "However, in a lot of cases, such as with the fumes released by the combustion engines in vehicles, we simply cannot control it," he added. "In cases such as this, reducing the emissions of these fumes, either through electrification or investment in carbon sequestering technology is key. "A key part of dealing with air pollution is tackling the issue at its source."

Donovan has noted several manufacturers, from factories to farmers - particularly in his native Ireland - have started generating their own wind power in a bid to cut emissions.

Air filtration is often put in place to protect the people and the environment or even to

Air purifiers are one method of ensuring clean air within a working environment, which can also have a number of added health benefits. Credit: Yuttana Jaowattana / Shutterstock Aspergillus spores are commonly found in the air in various climates around the world. Credit: Cornell Fungi / Flickr (Licence: CC 2.0)

help filter out dirty air from processes, however, the Camfil President points out that attempting to harness air filtration isn't a major factor regarding residential construction outside of personal investments into air purifiers.

He notes that proper filtration systems - whether talking about cycling air in factories or office blocs or hospitals - are "the most important part" of the heating and ventilation (HVAC) measures needed for indoor spaces owing to the need for local environments to be cleaned or to create conditions suitable for manufacturing.

Depending on the need, workplaces will cycle the air at different intervals to ensure it is clean enough for consumption while cycling out particulate matter to maximise both employee health and to prevent the matter from sticking to surfaces or affecting manufactured goods.

Manufacturers of particularly sensitive goods such as semiconductors or electronics may recycle the air several hundred times an hour to prevent particulate matter from sticking to, or damaging, the end product.

Donovan estimates manufacturing lines and cleanrooms for the pharmaceutical industry may recycle air "around 40-50 times per hour" to prevent too much of a build-up of dirty air.

A recent Harvard study indicated four to six air changes per hour in an indoor setting could reduce the airborne transmission rate of Covid-19, which could see wider applications outside of a pandemic scenario. The research suggests filtration systems may only be effective for long-range (6 feet and over) transmission of aerosols (saliva and mucus) and may not significantly affect close contact.

To conserve energy, companies may choose to only recycle the air when people are present inside of the buildings. Donovan hinted that many supermarkets and office spaces use automotive trackers to indicate when the system should start recycling air.

Humans may inhale as many as 25 sextillion molecules in a single breath. Millions of viruses may dawdle in the air through saliva or mucus dispersal from other humans, some of which may remain there for hours, meaning it is very important to keep the air cycled and clean.

He also emphasised the importance of proper air filtration in every aspect of building design, which can be important to the construction sector in other ways than simply ensuring the wellbeing of their own workers.

Donovan said: "If construction and industry don't get a handle on the right types of filtration, there's no point in trying to filter the air, as there may be a risk of continuing to recycle dirty air it can just make the situation worse. "I think the construction sector should strongly consider proper ventilation systems from every aspect, from the planning and design phase, to actually laying out and implementing the systems in a live setting. "Implementing these kinds of filtration systems into existing infrastructure can be difficult. We get clients that ask whether they can put HEPA filters in their buildings, and in most cases, they can't because the fans and motors won't be able to push their air due to extra restrictions, although you can use air purifiers inside the building itself to get around this."

He added: "HEPA filtration is the only real way to ensure clean air. The only way to ensure the adequate cycling of clean air is by absorbing the particles that make the air unclean but placing air purifiers inside the room can also aid in ensuring the air is clean enough."

When Camfil design air filtration systems they primarily look at two things: preventing air from getting in alongside adequate filtration and ensuring air purifiers are inside the building under the right conditions. "We've tested filters for companies and many of them will not stop anything," Donovan added. "It may be marketed as a HEPA filter, but it won't be doing what it says. Manufacturers must ensure the right balance of filtration systems for them to create a perfectly clean environment.

He continued: "The matter that manages to get through the systems can play havoc with our health, causing respiratory problems or getting anywhere you wouldn't want it to go."

The most common link for deaths from air pollution comes from PM2.5 - "PM" being the short-form for particulate matter. This can be commonly found by burning fossil fuels.

Camfil considers PM1 to be a "particularly dangerous" form of particulate matter owing to it being small enough to fit through filtration systems and get into a human's respiratory system. "Emissions are heavily regulated now which means the issue of carbon release may soon start to see a decrease," Donovan adds. "Furthermore, in many cases, such as with odours coming from a manufacturing plant, there may be a public interest in ensuring clean air to prevent bad smells or gas releases that could affect local communities." "You cannot just build a recycling plant or manufacturing plant without adequate filtration," he added.

Standards agencies and watchdogs have arisen over the years to tackle the issue of "shoddy filters", as Donovan puts it which may help provide companies with insight as to which services to use when constructing their filtration systems.

Brands known for ineffective filters may be "denied approval or certification by watchdogs", which could do something to weed out bad products and go some way towards passively improving air quality.

The ISO standard represents an international standard for several key industrial sectors. Standard 16890 pertains specifically to the quality of air filtration, monitoring both the grade of filter and the energy level, which may also help companies keep their filtration energy costs down, through simple means such as ensuring a filter has a larger surface area.

In the UK, a new air quality standard was pondered in June 2020 and was quickly mixed up in the politics of both Brexit and the coronavirus pandemic. A DEFRA study into the estimations for air pollution changes, concentration and exposures can be viewed here.

The US Environmental Protection Agency (EPA) has also introduced new standards and guidance for air quality in the wake of the pandemic. "Ensuring air quality is always tough," Donovan concluded. "Air, regardless of quality, will always find its way indoors and ensuring the right quality will always be difficult. "Ultimately, enforcing air quality standards will be very difficult, but helping people to understand the merits of clean air and proper filtration will help massively in the long run." n