airborne infection control in the design of green buildings: applications for upper-room ultraviolet...
DESCRIPTION
Upper room ultraviolet germicidal irradiation (UVGI) has shown great potential as an airborne infection control measure in the indoor environment. There is a growing literature on the benefits and applications of upper-room UVGI, however, designers looking to specify this technology often have difficulty due to a lack of general guidance on installation and operation of these systems. One potential approach is to include upper-room UVGI in an existing framework used in the design of high-performance green buildings. These aim to reduce the environmental impact of buildings and promote healthy environments for living and working. In settings with an increased concern for airborne pathogens such as hospitals, UVGI offers an energy efficient approach to providing additional air disinfection without increasing the capacity of HVAC systems. Studies have demonstrated UVGI performance in reducing pathogen concentrations with effective air changes several times greater than that accomplished by ventilation alone. These examples justify the application of UVGI in green buildings from both the perspective of energy efficiency and improved indoor environmental quality.TRANSCRIPT
Airborne Infection Control in the Design of Green Buildings:
Applications for Upper-room Ultraviolet Germicidal Irradiation
Kevin F. BanahanCandidate for Master of Science
Department of Environmental Health
Harvard School of Public Health
Objective
To demonstrate how an airborne infection control technology could be implemented into an existing framework for the design of green buildings
Outline
Upper-room UVGI What is green building? “Innovation in Design” credit for UVGI
What is UV-C?
http://www.uvcomparison.com/images/scienceUV-Cspectrum.jpg
Upper-room UVGI
http://www.ultraviolet.com/air/hygeai04.htm
distances in feet
High Levels of Air Disinfection
McDevitt JJ, Milton DK, Rudnick SN, First MW (2008) Inactivation of Poxviruses by Upper-Room UVC Light in a Simulated Hospital RoomEnvironment. PLoS ONE 3(9): e3186.
Eq. ACH due to UV
Cost-effectiveness Depends on:
Organism susceptibility Risk of transmission Site characteristics: air mixing, relative humidity, occupancy
Control StrategyPresent value ($) per TST
conversion
Increased Ventilation $1,708
Stand-alone HEPA $420
UVGI $133
Hypothetical scenario with TB in waiting room (Ko, 2001)
How to apply UVGI to design of Green Buildings?
Potential benefits Improved occupant health Energy efficient
Indoor Environmental Quality Minimum IAQ Performance (req’d) Environmental Tobacco Smoke Control (req’d) Outdoor Air Delivery Monitoring Increased Ventilation Construction IAQ Management Plan Low-Emitting Materials Indoor Chemical & Pollutant Source Control Controllability of Systems Thermal Comfort Daylighting and Views
“Innovation in Design” credit
“To provide design teams and projects the opportunity to be awarded points for exceptional performance above the requirements set by the LEED Green Building Rating system and/or innovative performance in Green Building categories not specifically addressed by the LEED Green Building Rating System.”
“Innovation in Design” credit
Innovation credit intent Requirement for compliance Submittals to demonstrate compliance Potential design approaches
Innovation Credit Intent:Reduction of Airborne Pathogens
Reduce risk of transmission of airborne disease Provide additional equivalent air exchanges for
airborne infection control Above the required outdoor ventilation rates
Requirements for Compliance
Design & installation by qualified professional
Verification of occupant safety during commissioning
Operations and Maintenance Plan
http://www.ultraviolet.com/air/hygeai03.htm
Potential Design Approaches
Upper-room UVGI In-duct UVGI Stand alone air cleaners Increased mechanical ventilation Natural ventilation
Conclusions UVGI in Green Buildings?
Potential for reduced risk of indoor air infection Energy efficient compared to alternatives
Upper-room UVGI should be considered on a site specific basis
Life-cycle assessment would improve design decisions for green building applications
Acknowledgements
Philip Brickner and Richard Vincent St. Vincent’s Hospital Manhattan,
Department of Community Medicine Robert Herrick
Department of Environmental Health, Harvard School of Public Health
Questions?