AMC filters are the first line of defense in commercial operation cleanliness and a key factor to ensuring high productivity. Activated carbon filters are widely used to remove a variety of low concentration chemical contaminants from commercial operations. It is difficult and unviable to test developmental filters at real-world concentration levels, which is why filter developers or independent labs test them under accelerated conditions. In the absence of standards for filter test concentrations, performance claims can vary widely from vendor to vendor, making it difficult for the end user to compare and understand the capabilities of various filters for fab applications.

In this study we show the impact of testing filters at various concentrations and the understanding of the filter performance consequently and why an evaluation is conducted at specific lower concentrations is more effective.

The HVAC industry often tests filters at concentrations as high as 100 parts per million (ppm, 10^‑6). Many AMC filter vendors test filters (or potentially only adsorbent samples) at con­cen­tra­tions between 3 and 100 ppm, the ISO standard 10121-1:2014 suggests a range of 9-90 ppm, all far above real-world applications, which might be as low as a few parts per billion (ppb, 10^-9). In other words, those applications are a factor of 1000-100000 below test concentrations. Filters being evaluated at 100 ppm vs. 1 ppm can significantly skew the understanding of the filter performance in terms of lifetime or capacity.

Controlled filter testing for single chemicals at varying concentrations shows the impracticality of performing tests at high concentrations much higher than the actual environmental concentrations. However, there are certain models that can, to a certain extent, predict performances at lower concentrations based on results at higher concentrations. These models, too, are limited, and the accuracy of measurements at single digit ppb levels is questionable.

Filtration solutions are often deployed without accurately knowing the contamination challenges of the environment to be protected. This is usually done to either implement a solution as quickly as possible, or to minimize cost by using pre-defined and readily available off-the-shelf solutions. However, this approach neither assures an efficient contaminant removal nor does it optimize cost of ownership. An inexpensive filter, which is replaced often, may have a higher cost of ownership over time than a customized, more expensive solution that has a greater capacity and longer life. Considering the high cost of the ...