From Best Media to Best Filter

<p class="font_8">High-performance filtration media can now be designed with targeted efficiency, airflow resistance, and particle capture behavior through advances in polymer science, nonwoven technologies, and simulation tools. However, good media does not automatically become a good finished filter. Once flat media is converted into a pleated element, the final filter performance may differ significantly from the original media data, especially in pressure drop, effective filtration area, dust-loading capacity, and long-term stability.</p>
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<p class="font_8">This presentation focuses on the engineering transition from media selection to pleated filter design. Before optimizing the filter structure, engineers must first define the real application requirements, including operating temperature, humidity, air pressure, airflow rate, service life, dust characteristics, installation space, existing housing, and performance targets. Laboratory test results are important, but actual field conditions may introduce different particle challenges, airflow patterns, and environmental stresses; therefore, field validation is often necessary.</p>
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<p class="font_8">After suitable media candidates are selected, properties such as air permeability, thickness, stiffness, compressibility, and mechanical stability must be evaluated. These properties directly influence the achievable pleat geometry. Filter pressure drop is not only determined by the media itself, but also by air entry into the pleats, friction along the media surface, airflow through the media, and air exit from the pleats. Increasing pleat count can reduce pressure drop by increasing media area, but only up to an optimal point. Excessive pleat density may deform the pleats, restrict airflow, reduce effective media utilization, and increase blockage from scoring or spacing features. An ideal V-shaped pleat may become a less efficient Y-shaped structure if the media lacks rigidity or the spacing design is not well controlled.</p>
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<p class="font_8">Therefore, successful filter design requires balancing media performance, pleat count, pleat depth, spacing method, structural support, manufacturability, cost, and application risk. Embossing, separator glue, plastic fingers, and aluminum separators can help control pleat geometry, but each solution involves trade-offs. The goal is not simply to use the “best” media, but to create the best practical filter for the application.</p>

Speaker Bio

Dr. Lu Liu is a Principal Engineer in Parker Hannifin’s HVAC Filtration Division and a 2026 Parker Engineering Fellow—one of the company’s highest technical honors, recognizing exceptional leadership, innovation, and impact in critical applications. Representing Parker’s Filtration Group, Dr. Liu is widely recognized for advancing next-generation filtration materials, product design, and manufacturing methods. Since joining Parker in 2014, she has played a pivotal role in improving both filtration performance and manufacturability, including significant advancements in the LPD filter construction method that support scalable, high-quality production. Her expertise in fiber and polymer science has helped strengthen Parker’s HVAC filtration solutions for demanding environments such as healthcare, agriculture, and data centers. As one of only two engineers in Parker’s Filtration Group to receive this distinction, Dr. Liu also holds four patents, has published five journal articles, and maintains active leadership and engagement with ASHRAE, NAFA, AFS, and WFI.

Presentation time

December 9, 2026
9:25 am - 10:35am EST

Abstract

High-performance filtration media can now be designed with targeted efficiency, airflow resistance, and particle capture behavior through advances in polymer science, nonwoven technologies, and simulation tools. However, good media does not automatically become a good finished filter. Once flat media is converted into a pleated element, the final filter performance may differ significantly from the original media data, especially in pressure drop, effective filtration area, dust-loading capacity, and long-term stability.

This presentation focuses on the engineering transition from media selection to pleated filter design. Before optimizing the filter structure, engineers must first define the real application requirements, including operating temperature, humidity, air pressure, airflow rate, service life, dust characteristics, installation space, existing housing, and performance targets. Laboratory test results are important, but actual field conditions may introduce different particle challenges, airflow patterns, and environmental stresses; therefore, field validation is often necessary.

After suitable media candidates are selected, properties such as air permeability, thickness, stiffness, compressibility, and mechanical stability must be evaluated. These properties directly influence the achievable pleat geometry. Filter pressure drop is not only determined by the media itself, but also by air entry into the pleats, friction along the media surface, airflow through the media, and air exit from the pleats. Increasing pleat count can reduce pressure drop by increasing media area, but only up to an optimal point. Excessive pleat density may deform the pleats, restrict airflow, reduce effective media utilization, and increase blockage from scoring or spacing features. An ideal V-shaped pleat may become a less efficient Y-shaped structure if the media lacks rigidity or the spacing design is not well controlled.

Therefore, successful filter design requires balancing media performance, pleat count, pleat depth, spacing method, structural support, manufacturability, cost, and application risk. Embossing, separator glue, plastic fingers, and aluminum separators can help control pleat geometry, but each solution involves trade-offs. The goal is not simply to use the “best” media, but to create the best practical filter for the application.