Rensa Filtration, an Audax Private Equity portfolio company and manufacturer and distributor of consumable, mission-critical air filtration solutions, announced that it recently acquired IREMA-Filter GmbH and its U.S. subsidiary Aeolus Filter Corporation from PINOVA Capital.

IREMA was founded 50 years ago near Postbauer-Heng, Germany and is an innovator in filtration media and filter media pleating technologies. Based in Archdale, NC, Aeolus Filter provides filters using IREMA’s media and pleating technologies and has a strong market presence in critical data center and healthcare air filtration applications.

Brandon Ost, CEO and Founder of Rensa Filtration, noted, "We’re excited to partner with the IREMA and Aeolus management team, employees and their customers. The filtration market has long held the IREMA/Aeolus business and filter technology in high regard, and we look forward to supporting their continued technology development, increased manufacturing capacity and commercial growth. This investment in IREMA underscores Rensa’s commitment to quality and innovation.”

IREMA’s filter media process technology is a flexible platform capable of making both polymeric microfibers and nanofibers and combining them to make innovative filter media structures with multiple layers, gradient structures, and mixed micro and nanofiber structures. For end users, these technologies enhance both the dust-holding capacity and service life. The media can be electrostatically charged or fully mechanical in nature. Because it is completely polymeric, the media has high moisture resistance and mechanical durability and does not support microbial growth. Finished filters can be recycled or sent to waste-to-energy facilities.

The World Health Organization (WHO) and scientific studies have identified PM 2.5 (airborne contaminants less than 2.5 microns in size) as detrimental to human health and these fine particles are a key component of the AQI (Air Quality Index). IREMA’s polymeric nanofiber depth loading media leads to high filtration efficiencies on PM 2.5 and submicron contaminants, combined with long service life and energy efficiency.

Dr. Andreas Seeberger, CEO of the IREMA group adds, “Rensa Filtration is the ideal partner for us. Their track record in mission critical filtration applications and focus on innovative solutions is a great fit for IREMA’s core competencies and unique technologies. We are excited to be a part of the Rensa family and together we will seek to drive innovation and growth even faster.”

The acquisition marks the ninth acquisition since Audax invested in Rensa in 2022. “This acquisition checks a number of boxes for Rensa,” noted Joe Rogers, a partner at Audax Private Equity. “Beyond building out the company’s solution set and extending its footprint into Europe, the combination of Rensa, IREMA and Aeolus Filter enhances the value proposition to customers seeking a range of high-quality, innovative solutions.”

“It was exciting to accompany and support IREMA on this phase of further internationalization and growth. Rensa is a compelling fit to seize the business opportunities in both, the European and the U.S. market,” continued Herbert Seggewiss, a Managing Partner of PINOVA Capital.

Terms of the deal are not disclosed.

Baird and Harris Williams served as advisors to the buyer, while Stephens Inc. advised the seller on the transaction. Ropes & Gray LLP and Oppenhoff provided legal counsel to Rensa, while CMS served in the same capacity for the seller.

About Rensa Filtration

Rensa is a leading designer, manufacturer and distributor of highly engineered, consumable air filtration solutions focused on protecting people and systems in critical environments and applications. Rensa offers a wide range of standard and customized air filtration products that provide best-in-class filtration performance and energy savings in education, healthcare and high-tech manufacturing facilities. Rensa also offers specialized air filtration solutions for data centers and activated carbon filters for the removal of odors and molecular contamination in museums, airports and healthcare facilities. For more information, visit rensafiltration.com or follow us on LinkedIn.

ABOUT AUDAX PRIVATE EQUITY:

Headquartered in Boston, with offices in San Francisco, New York, London and Hong Kong, Audax Private Equity manages three strategies: its Flagship and Origins private equity strategies, seeking control buyouts in the core middle and lower middle markets, respectively, and its Strategic Capital strategy that provides customized equity solutions to PE-backed portfolio companies to help drive continued growth. With approximately $19 billion of assets under management as of March 2025, over 290 employees, and 100-plus investment professionals, Audax has invested in over 175 platforms and more than 1,400 add-on acquisitions since its founding in 1999. Through our disciplined Buy & Build approach, across six core industry verticals, Audax seeks to help portfolio companies execute organic and inorganic growth initiatives with the aim of fueling revenue expansion, optimizing operations, and significantly increasing equity value. For more information, visit www.audaxprivateequity.com or follow us on LinkedIn.

ABOUT PINOVA Capital:

PINOVA is an independent private equity company that invests in Industrial Tech companies (High Tech Components, Innovative Materials and Smart Systems) in the German-speaking region through its managed funds. PINOVA focuses on mid-sized companies with revenues between €10 million and €50 million characterized by significant growth potential, sustainable competitive advantages, and a strong market position in their niche. Further information can be found at: pinovacapital.com.

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