Advanced air filter could enable building vents to capture carbon and reduce energy use

by Paul Dailing
Chicago IL (SPX) Nov 12, 2025

Researchers at the University of Chicago Pritzker School of Molecular Engineering have developed a nanofiber air filter designed for building ventilation systems that captures airborne carbon dioxide and could lower household energy costs.

The team, led by Assistant Professor Po-Chun Hsu, designed a distributed carbon nanofiber direct air capture filter that transforms residential and commercial HVAC systems into localized carbon-capture sites. The filter operates with over 92 percent efficiency in extracting carbon dioxide from indoor air, even after factoring in emissions associated with production, transport, and disposal.

First author Ronghui Wu noted that integrating carbon-capture filters into ventilation infrastructure could remove CO2 without constructing new facilities or requiring additional land. Replacing all conventional building filters with this nanofiber version could eliminate as much as 596 megatonnes of carbon dioxide annually, comparable to removing 130 million vehicles from service for a year.

A study conducted in 2024 found that using these filters could reduce building energy expenditures by up to 21.66 percent. Standard HVAC systems pull outside air to lower indoor CO2 levels, but the carbon-capture filter removes CO2 from indoor air directly, resulting in less need for temperature adjustment and lower overall energy consumption.

The design allows the CO2 to be released from the saturated filter using solar heat, enabling regeneration using renewable energy sources. By employing a carbon nanofiber-polyethylenimine material, the filter matches the form factor of traditional HEPA filters but enables regular recycling and reactivation rather than landfill disposal.

The researchers propose a system where waste management services periodically collect spent filters for centralized CO2 extraction. The concentrated CO2 could be sequestered or used as a feedstock for chemicals or fuels.

This filter also enhances indoor air quality, particularly in crowded settings such as offices or classrooms, contributing to improved alertness and well-being.

Research Report:Distributed direct air capture by carbon nanofiber air filters

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