Airborne Pathogen Cycle

The Airborne Pathogen Cycle diagrams below show how germs are circulated in the ambient air. Too often we are unaware of the dangers in our indoor air we breathe and how it can affect our overall health. HVAC systems can circulate pathogens and carry them to everyone within a building. Penn State Department of Architectural Engineering has research indicating how tuberculosis from an infected person can travel in HVAC systems from the first floor of a building to the tenth floor in as little as eight hours. The article is titled “Spread of Disease in Office Buildings”1.
The Airborne Pathogen Cycle demonstrates the effects of coughing, sneezing, talking, singing, breathing diarrhea pathogens and toilet flushing droplets on the air we breathe. Viruses can be airborne for long periods of time, like the study done by Dr. Liu Juianlun in February 2003 which indicated the SARS virus was present in the Metropole Hotel hallway air (slide nine), two months after it was first discovered. Infectious droplet nuclei can travel from one person to another as far away as 160’ or more feet and even further within an air circulation system.
Photocatalytic Oxidation can significantly reduce malignant microbes in the ambient air. The Airborne Pathogen Cycle shows how Photocatalytic Oxidation air purification/filtration works. Please feel free to contact us with any questions or comments.

1.http://www.engr.psu.edu/iec/abe/topics/office.asp

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Steven Welty

Steven Welty is a specialist in airborne infectious diseases,
filtration and HVAC energy efficiency. Steve uses computer
modeling to design airborne infection control systems using
ultraviolet light, photocatalytic oxidation, Bi-Polar ionization and
high MERV filters. Steve is an IAQ investigator who solves air
quality issues in hospitals, office buildings, schools and homes.

Steve is a LEED® AP, CIE (Certified Indoor Air Environmentalist)
and a CAFS (Certified Air Filtration Specialist). Mr. Welty is
chairman of the Indoor Environmental Standards Organization
(IESO) committee which is writing a new school IAQ standard:
“Standard Guide for the Inspection of an Educational Facility for
Moisture Intrusion and Mold Growth”.) Mr. Welty has
extensively lectured on and written articles about airborne
infectious diseases, HVAC energy efficiency, indoor air quality, air
filtration and liquid desiccant dehumidification. Steve is the
President of Green Clean Air based in Reston, VA.
steve@GreenCleanAir.com I 703.927.7532.

Contact us

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Ph: 772.569.5955
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