According to WHO statistics, air pollution causes an alarming mortality rate of two million premature deaths a year around the world. Gaseous pollutants and particulate pollutants are the main sources of air pollution. Gaseous pollutants generally include volatile chemical contaminants or malodorous substances that could lead to cancer. Particulate pollutants are atmospheric particulate matter (PM) and those that are 2.5 microns in diameter and less are especially harmful as they can penetrate into alveoli and through vascular walls into people's blood circulatory system, jeopardizing the respiratory, cardiovascular, and nervous systems.
An observation of Google Trends shows the number of searches for air purifiers in Taiwan has grown a whopping 270% in the period from 2015 to 2017, an indication that people in Taiwan are placing increasing importance on air quality. In light of this, CHD Tech, founded in 2005, is leveraging its extensive experiences in building semiconductor clean rooms accumulated over the years to craft air quality management solutions in the hope of effectively eliminating invisible health hazards including chemical contaminants (e.g. formaldehyde) and PM.
Optimal air filtering performance is achieved along with meticulous spatial design
Nicholas Su, executive assistant to general manager, CHD Tech, indicated clean room project budgets generally start from tens of millions of NT dollars and could run up to NT$100 million. Business owners usually retain 10% of the amount as final payment after CHD Tech's project passes closing inspections including stringent acceptance checks on leakage, cleanness, and other criteria. The technological know-hows in building clean rooms are similar to those for making non-industrial air purifiers so CHD Tech uses the same foundry-grade supplies to craft total air quality solutions that rise above conventional home appliances. Not just selling air purifiers or ventilation systems, CHD Tech also carefully designs the details such as equipment installation and return air path and uses professional instruments to conduct on-site checks and provide customers complete air quality inspection reports.
CHD Tech's air solutions mainly comprise AP-550 air purifier and AW-450 fresh air system, respectively handling critical internal and external circulation, said Su.
AP-550 is designed with a HEPA filter that spreads out to 16.9 meters in length, equivalent to the height of a six-story building, and an 8.8 square meter area, five times that of a common air purifier on the market. More importantly, AP-550 achieves airtight seal and continuous filtration with its aluminum frame, double-sided airtight design, and mesh screen, compared to conventional products that generally use paper frames without airtight design and therefore deliver less-than-optimal filtration effects due to leakage.
In addition to the HEPA filter, AP-550 comes with two extra filters??an activated carbon filter and a pre-filter. In particular, the activated carbon filter weighing 1.7 kg absorbs odorous substances with granular activated carbon and formaldehyde with aluminum oxide and zeolite, significantly removing harmful chemicals. On the other hand, most products available on the market only have a small amount of activated carbon powder on non-woven fabric and therefore can hardly generate comparable filtering effects due to the minimum number of absorption pores. It should also be noted that AP-550 is designed with laminar air flow, different from the turbulent air flow of conventional models, so with its air outlet positioned at the height of 123cm, it can ensure clean air in the layer where people breathe. Furthermore, by separating the air paths of the upper air outlet and the lower air intake, AP-550 enables optimal interior circulation so users can enjoy a clean and healthy surrounding whether standing, sitting or lying down.
AW-450, drawn from the concept of a clean room make-up air unit (MAU), purifies outdoor air using industry-leading air washer technology to first filter out water-soluble chemical contaminants and then eliminating non-water-soluble pollutants such as PM with a HEPA filter and sends clean air to the indoor environment. One may be curious about whether a ventilation system functions the same as a heat exchanger in theory. A heat exchanger maintains a stable temperature through heat transfer without filtering out bacteria or PM and thus is quite different from a ventilation system, explained Su.
Ventilation systems with laminar air flow and air washer achieve powerful filtration of pollutants
Putting the combination of AW-450 and AP-550 to use will deliver the double benefits of cleansed outdoor air and repurified indoor air, eliminating over 90% of PM and over 80% of chemical contaminants in the air.
Su further pointed out CHD Tech also provides accessory units such as the SAR900 fan filter unit available with different duct configurations to help with indoor air purification or outdoor air cleansing. CHD Tech is also introducing the AP-204 PM air purifier suitable for a 23 square meter indoor space (calculated based on the rate of 4 air changes per hour), priced at a little more than NT$10,000, to meet the air purification needs of small areas. Despite its compact size compared to AP-550, AP-204 also comes with a HEPA filter enabling over 90% PM removal and a far superior CP ratio compared to other air purifiers on the market.
CHD Tech is accumulating use cases of its air solutions. One example is the use of CHD Tech's AP-550 air purifier in the laboratory of the Department of Engineering Science and Ocean Engineering, National Taiwan University. Experiments in the lab generate a significant amount of ceramic dust over time which contains harmful substances potentially causing cancer, such as lead. This prompted the institution to search for industry or clean room class air purifiers in the hope of effectively reducing PM10/2.5/1.0 particles. Upon careful evaluations, CHD Tech's AP-550 was selected.
According to measurements obtained using an Aerocet 831 aerosol mass monitor, the concentrations of PM2.5 and PM10 in the lab were respectively 126?gg/m3 and 147?gg/m3 before the use of AP-550, at least two times higher than the legal limit (35?gg/m3). After putting AP-550 to use, Aerocet 831 readings taken at the air outlet showed zero PM2.5 and PM10 concentration, an amazing 100% removal rate.
A second success story happened at the Taoyuan Shulin Elementary School. Neighboring petrochemical factories in the Guanyin Industrial Park on three sides, the school has long been situated in an environment full of industrial air pollution. Caring for the health of the students and teachers, CHD Tech decided to donate several units of AW-450 and AP-550 to the school to help cope with the different requirements of outdoor ventilation and indoor circulation. On-site measurements at the school using a HAL-HPC300 handheld particle counter and an aeroQUAL Series 200 formaldehyde gas monitor showed an indoor formaldehyde concentration of 0.42ppm, 4.25 times higher than the legal limit (0.08ppm), indicating a dire need for improvement. With the AW-450 and AP-550 units in operation, formaldehyde concentration dropped to 0.02ppm, a removal rate of 95.24%.
One more application scenario of AP-550 was in a soap factory of a biotechnology company, where the soap scraping operation causes dust to rise in the air, resulting in a constantly high PM2.5 concentration. A measurement taken by CHD Tech at the site indicated a concentration level of 93?gg/m3. The factory then introduced AP-550 and thereby successfully reduced PM2.5 concentration by over 91% to 8?gg/m3, an experience that others can draw from.
CHD Tech now mainly relies on its sales team along with word-of-mouth marketing to promote its air quality management business and plans to incorporate online marketing in the future to strengthen its expansion, commented Su. Target markets will include hospitals, clinics, postpartum care centers, chemistry labs or pharmaceutical labs where concentrations of PM or harmful chemicals are generally higher and therefore there is a greater need for air purification.
AP-550 air purifier
AP-550 air purifier