ASHRAE's IAQ series of conferences started in 1986 and this 16th installment was held for the first time outside of the United States in Kuala Lumpur, Malaysia, November 10–12, 2010. By the quality and quantity of papers, workshops and plenary talks, the number of attendees, comments from attendees and all other measures, it was a resounding success.
The IAQ conferences have had a history of addressing specific themes and attracting the world's most authoritative experts on indoor air quality, as well as the most up-to-date technical and practical information on the subject. The IAQ 2010 conference did this by addressing a very important and topical theme: Airborne Infection Control—Ventilation, IAQ & Energy. This theme is important and timely for many reasons, including worldwide concern about potential outbreaks of infectious disease; the need to validate healthcare design methods; and, the energy cost and carbon footprint of ventilation interventions, especially in hot and humid climates.
The Ministry of Health, Malaysia, played a significant role in this conference. Dato’ Sri Liow Tiong Lai, the honorable Minister of Health, officiated at the welcome dinner and gave a strong endorsement of this conference in his address. The building, healthcare, and aviation industries are increasingly faced with the challenge of providing healthy indoor environments. The Severe Acute Respiratory Syndrome (SARS) episode, the influenza A (H1N1) pandemic, and fears of avian flu have transformed the indoor environment landscape, raising not only significant public health concerns but also economic implications on a global scale. Airborne infection and its control in the enclosed environment have tremendous impact in the design, operation, and maintenance of buildings and other enclosed environments. The dimensions of climate change and environmental sustainability pose further challenges to an already complex problem. IAQ 2010 reviewed the state of knowledge about airborne infection and helped define future directions for research, applications and standards.
Over two and a half days, the conference covered the latest in airborne infection control, featuring internationally acclaimed keynote speakers, original peer reviewed papers, plus workshops with panel discussions. Some of the questions that were deliberated included:
| • | Is airborne infection in enclosed environments emerging as a primary IAQ and health concern? | ||||
| • | What is our current understanding of the airborne infection route in enclosed environments, including buildings and transportation conveyances? | ||||
| • | What is the status of airborne infection control techniques adopted in different types of enclosed environments and our knowledge about their effectiveness? | ||||
| • | How do mechanical systems and other building and enclosure characteristics contribute to healthy environments in an energy-efficient manner? | ||||
| • | How can we create and sustain healthy enclosed environments through design, construction, commissioning, operation, and maintenance? | ||||
| • | What government and private sector programs exist or are proposed, including standards and guidelines for infection control and pandemic-preparedness in enclosed environments? | ||||
| • | How well are the existing programs working and what roles can ASHRAE and other organizations in the field of building science and conveyance design play? | ||||
The technical proceedings of IAQ 2010 comprised four plenary lectures, four workshops, and ten technical sessions. Forty-five papers were presented as original peer-reviewed papers at the conference. Of these, fifteen were selected to be expanded to full articles, of which ten are included this special issue of HVAC&R Research.
Ventilation systems and airborne infection
Topical papers on ventilation systems and airborne infection, consisting of two technical sessions, addressed the issues of airborne infection associated with different types of HVAC systems. Of the papers presented, three were selected for expansion to full articles. Nielsen et al. deal with exhaled aerosol transport in experimental studies between two people in a displacement ventilated room. Pantelic and Tham use the Wells-Riley approach to assess the ability of different ventilation systems to serve as a control measure against airborne infectious disease transmission. Particle movement under different air distribution is explored by Xiaoping et al. to evaluate the impacts on inhalation by co-occupants.
Airborne infection in healthcare facilities
Nine topical papers on airborne infection in healthcare facilities, consisting of two technical sessions, deal with the issues of airborne infection specifically in healthcare settings and three papers are included in this special issue. Modeling and measurement of air contaminant distribution in an operating room ventilated with split system was discussed by. Pereira et al. deal with the approach of measuring concentration and size of aerosol and identification of sources in an orthopedic surgery. Exposure of health care workers to coughed airborne pathogens in a double bed hospital room with overhead mixing ventilation is explored by Bolashikov et al. H. Wang et al. present their findings of a study dealing with the identification of index (source) patient location of SARS transmission in a hospital ward.
CFD and other modeling techniques
Two technical sessions addressed the topic of computational fluid dynamics (CFD), and other modeling techniques, with seven papers presented that used CFD simulation and other modeling techniques to study airborne infection issues in enclosed environments.
Airborne bacteria and viruses
Five papers addressed airborne bacteria and viruses that dealt with subjects ranging from a method for evaluating the sampling efficiency of bio samplers for airborne bacteria to mechanisms dealing with the aerial dissemination of clostridium difficile spores and potential for engineering control. However, none of the five papers from this topic are included in this special issue.
UVGI and other air cleaning techniques
Six papers presented dealt with ultraviolet germicidal irradiation (UVGI) and other air cleaning devices used to control airborne infection, of which two papers are in this special issue. Lau et al. explore the effectiveness of the in-duct ultraviolet germicidal irradiation devices by modeling various lamp configurations. The effects of various indoor environmental factors on the decay of chlorine dioxide gas concentration and their implications on its use against pandemic flu is explored by Tsutsumi et al.
IAQ and energy in healthcare facilities
Five papers addressed IAQ and energy issues in healthcare facilities; two papers are included in this special issue. Noakes et al. appraise healthcare ventilation design from combined infection control and energy perspectives. The field evaluation of thermal comfort and indoor environment quality for a hospital in a hot and humid climate is presented by F. Wang et al.
Natural ventilation
Finally, three natural ventilation papers were presented.
Summary
Some key messages that emerged from the conference were:
| • | Continued lack of certainty about the benefits of forced ventilation over natural ventilation, even for infection control. | ||||
| • | Lack of quantitative scientific justification for the dilution ventilation rates in our guidance documents. | ||||
| • | Knowledge that proximity to an infected person affects infection rate, but the continued lack of certainty about whether that is due to large “ballistic” droplets or just a higher concentration of smaller airborne particles. | ||||
Besides the papers from the IAQ 2010 conference mentioned above, this special issue also includes an ten additional papers on similar research areas.