According to Dr. Iyad Al-Attar, people demand the best indoor air quality, despite weak filter specifications, inaccurate filter selection, conventional filter design, poor maintenance practices, unqualified maintenance team, expensive filtration mistakes, irrecoverable filter performance losses, etc.
Al-Attar is a mechanical engineer and a renowned air filtration consultant. He is also a member of the “IAQ International Society of Indoor Air Quality and Climate” as well as the Aerosol Society in the United Kingdom.
He says: “Eventually, filter failure is bound to happen. Failing to believe in the consequences of filtration malpractices and inappropriate filter selection, makes us subject to short- and long-term contaminants exposures.”
He adds that the use of conventional air filters is still in demand and entertained by a wide range of users, contractors, and consultants. Al-Attar says: “Washing a disposable filter is still considered a maintenance measure rather than a mistake.”
In the GCC, filtration solutions and standards need to be re-visited given the excessive temperature, relative humidity levels, and high dust concentrations. The filter performance is affected by such conditions and deviate from that predicted by the laboratory test reports. However, Al-Attar adds that filter purchasing is a price-driven endeavour usually delegated to purchasing executives that lack the basic engineering knowledge required to assess filters performance and conduct fair comparison. He says: “A price-driven market places less emphasis on R&D. That would possibly explain why GCC markets are flooded with conventional products with technology traces from slim to none.”
In addition, there are no incentives from the government for improving IAQ. He says: “Governments neither rewards outstanding achievements in enhancing IAQ nor fines for not doing so. In other words, there are no marks for enhancing air quality, and therefore, there is no fine for committing a filtration mistake that degrades the air quality. If our thermal comfort or plumbing system are compromised, an immediate attention/action is sought. However, we underestimate the patience of our respiratory system that could be prone to asthma attacks.”
Achieving better IAQ
Al-Attar says that the first and foremost thing to keep in mind is to not consider IAQ as a business. He adds: “There too many gaps to close between manufacturers, end users, consultants and buyers, let alone the suitability of intentional standards to the regional filter performance. While the new standard brings about a positive change to filter selection, it will alone not enrich our filter acquisition if it is not backed by a compliance and incentive system.”
Air filtration is considered the most effective method of separating particles from the air stream. However, Al-Attar says that it is important to realise that “air filtration is not the main cause of poor indoor air quality and therefore it is not the only solution”. Some pollutants are emitted from within the indoor space where ventilation and internal filtration techniques may be employed to tackle such sources of contamination.
One of major concerns in IAQ, is the misconception of addressing air filtration as tool only to capture solid particles. By doing so, many anthropogenic gaseous contaminants are overlooked such as NOx, SOx, carbonaceous particles and soot. When such contaminants settle on the surface/depth of the filter, they can undergo oxidation of different rates and the filtration process can alter. Consequently, to remedy such a challenge, filter selection should vary to accommodate and remove unwanted contaminant whether it is solid, liquid or gaseous. Additionally, deposited particles can have different chemical composition, and can be partly volatile and undergo physicochemical reactions and changes during both the filtration process and sampling process.
He says: “An essential step towards a corrective action in improving IAQ is air quality monitoring via sampling and air filter performance assessment via testing. Air sampling is a key tool in assessing when we should eventually challenge the filters installed in our air handling units. Filter testing reveals the performance post manufacturing and during operation to fulfil the ethical obligation of delivering clean air to the indoor occupants. Given the sophisticated sampling capabilities available today, IEQ must be second to none, not a dry run. When there are no monitoring systems for IAQ that measure a wide array of contaminants, consultants, contractors, maintenance/HVAC team and/or manufacturers cannot be held responsible for poor indoor air quality.”
Implementing an energy-saving approach in HVAC operations is essential and smart filter designs can contribute substantially in that regard, says Al-Attar. “Good indoor air quality can be achieved through aerodynamic (low-pressure drop and efficient) air filters, which consequently influences the overall air handling unit energy usage. Filter media is a key to better filtration performance and energy saving: New innovation in filter media are ready to be implemented but must find its way into our AHUs simply by being specified by consultants and enforced by governments and employed by contractors.
“However, the initial drive is to enhance IAQ while keeping an eye on energy consumption. Power is generated to provide humans not only with thermal comfort, but also to safeguard the indoor environment by keeping concentration levels of the pollutants below the threshold set forth by international standards. With today’s advances in HVAC and air filtration, providing an appropriate indoor climate for people is within reach. However, we cannot compromise IAQ by degrading the filtration selection and reducing filtration stages just to achieve energy savings.”
According to him, the intelligent question that begs an answer is, why higher class air filters have high pressure drop, and therefore, consume a great deal of energy? Shouldn’t the term “efficient” also mean efficient in energy consumption not just particle capturing?
Another aspect in the role of filtration is capturing atmospheric particles prior to introducing them to the compressor of the gas turbine and then onwards to the combustion chamber. It is imperative that such compressors be kept clean to perform as close as possible to its design point. Research has established that 70-85% of gas turbine performance degradation is due to compressor fouling where reliance on air filters to do so is substantial. Yet, hot gas filtration emerges again a great tool to play a role in reducing gas turbine emissions. Al-Attar says: “There is no reason why fossil fuels cannot be used in gas turbines, provided they are burnt responsibly. That is, the gas turbine should be operated as efficiently as possible, namely at its design point (base load). On the other hand, employing renewable energy techniques can also play a role in reducing emissions while generating power.”
The entire topic of clean air should be approached from a different perspective, says Al-Attar.
He adds: “We pollute a great deal, and therefore, we need to clean a great deal.”
Al-Attar says that our tactics to improve air quality are limited to two folds:
Firstly, we rely single-handedly on “increasing awareness” to get everyone involved in the selection process to source the latest and best filtration technologies. Secondly, we assess air filter by mere “eye-balling” for structural integrity of filtration products and their test reports mainly assess filter performance is simply an illusion. We are in need of a standard measuring stick for filter performance as some measure the greatness of a filter performance by re-generation frequency, i.e., cleaning (by air or water) to extend the filters lifetime. This chronic practice exemplifies a typical malpractice in our region.
Al-Attar concludes by saying: “Having the intentions alone to enhance IAQ will not yield clean air. What we lack is an authentic approach to enhancing IAQ and implementation strategies to execute it. Furthermore, we need to re-invent the entire maintenance practices, air filter manufacturing and rewrite our understanding of air filtration, clean air, and the consequential health effects should we fail to adapt such an approach.”