SBIR-STTR Award

The COVID-19 pandemic has heightened awareness of the role airborne pathogens play in transmitting infection and will leave a legacy of focused attention on indoor air quality for the foreseeable future. Indoor enclosed spaces are high-risk environments for increased transmission of aerosolized pathogens like COVID-19, SARS, influenza, and other yet-to-emerge diseases. Many situations, including offices, aircraft cabins, classrooms, and public transportation, place humans in close proximity, where aerosolized pathogens are a threat. Centralized HVAC systems, while providing a proportion of fresh air, can actually spread pathogens under certain circumstances. While several air purification solutions are currently available, including those based on emerging technologies, independent studies have shown many to be much less effective than they claim under real-world operating conditions. Approaches employing HEPA filters, which are good at removing airborne pathogens, come with a high cost burden and energy penalty for centralized systems. The proposed product is an air purifier that employs photocatalytic technology for use in centralized HVAC systems to capture, kill, and destroy airborne bacteria and viruses, reducing the concentration of airborne pathogens in enclosed or semi-enclosed spaces. This novel approach has a pressure drop 1/5th to 1/10th that of a comparable HEPA system, allowing for its addition to existing HVAC systems with limited modification. This photocatalytic air purifier will also eliminate VOCs from the air with greater than 99% single-pass removal efficiency without the release of harmful intermediates or the use of carbon adsorbents, which require changeouts and disposal. The markets for air purification are large and growing strongly. World-wide, the air purification market was $10.7B in 2020 and is projected to grow to $22.8B by 2028. The target market for this technology is occupied commercial spaces, including office buildings, restaurants, hotels, health care facilities, schools, and public transportation. The envisioned product is suitable for airborne antimicrobial control in existing HVAC systems as well as in new equipment. This technology will form the basis for multiple products in pathogen removal that will reduce transmission of airborne communicable disease to increase the confidence of workers and travelers, thereby improving the economy as well as worker productivity.

The COVID-19 pandemic has heightened awareness of airborne pathogens and their role in transmitting infection throughout the population. The threat of airborne pathogens extends beyond SARS-CoV-2. Diseases caused by airborne viruses (Influenza), bacteria (Legionnaires’ disease and Tuberculosis), and fungi (aspergillosis) are also prevalent, with Influenza estimated to cause 200,000–500,000 worldwide deaths annually. Additionally, airborne pathogens such as Bacillus anthracis (anthrax) present a viable bioterrorism threat. Indoor environments increase the risk of airborne disease transmission. HEPA filters are effective at removing airborne pathogens, but they come with a significant cost burden and energy penalty. While several emerging technologies have been introduced in the market, third-party validation of efficacy is either lacking or has demonstrated lower effectiveness levels under real-world test conditions than performance claimed by manufacturers. The opportunity exists to create a sustainable, energy-efficient solution to reduce airborne pathogens in indoor spaces. The Phase I project investigated the feasibility of Sonata’s photocatalytic VOC abatement platform to mitigate airborne pathogens. The project separately evaluated pathogen capture and neutralization functions in indoor environments. Inactivation rates exceeded the Phase I goal, even under the most energy efficient test conditions. When operating within the energy envelope of a typical HEPA filter (including blowers), the technology demonstrated a 3-log10 kill efficiency in 30 minutes for S. epidermidis. A 4-log10 inactivation was achieved for MS2 bacteriophage in 5 minutes. The scaled photoreactor, operating at 10 CFM, was efficient at removing 3-log10 of both S. epidermidis and MS2 bacteriophage in 30 minutes from a 1 m3 chamber. The system has a pressure drop approximately 20% of a new HEPA filter. This performance validation will be extended in Phase II, which will focus on scaling the system to 100 CFM flow rates while optimizing pathogen capture and energy efficiency. The target market is occupied commercial spaces, which includes office buildings, restaurants, hotels, health care facilities, and schools. The envisioned product is suitable for airborne antimicrobial control in existing HVAC systems as well as new equipment. The markets for air purification are large and growing strongly; the world-wide air purification market was $10.7B in 2020 and is projected to grow to $22.8B by 2028.