ATLANTA - According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), natural ventilation has been promoted as a cure-all to reduce cost and energy consumption and to improve indoor air quality and occupant comfort. However, the reality of natural ventilation is more complicated.

A workshop discussing the design and performance of natural systems will be featured at ASHRAE’s IAQ 2007: Healthy and Sustainable Buildings conference, in Baltimore, Oct. 14-17.

In the workshop, “What’s So Great About Natural Ventilation,” Steve Emmerich and Andy Persily, both with the National Institute of Standards and Technology, will discuss how natural ventilation systems relate to existing ventilation, thermal comfort, and energy standards, and present experiences in Europe and Asia along with actual performance measurements. Other IAQ 2007 speakers on natural ventilation will join the workshop for a panel discussion on the topic.

“The design of natural ventilation systems for air distribution and reliability of ventilation rates over a range of weather conditions is more complex than many designers realize,” Emmerich said. “Also, issues of outdoor air quality, including moisture impacts, are not always addressed in system design.”

Limited data is available on the performance of these systems in terms of outdoor air ventilation rates, thermal comfort parameters, and indoor pollutant levels, according to Emmerich.

Other workshops at IAQ 2007 are:

• “Development of an Advanced IAQ Design Guide,” presented by Andy Persily, chair of ASHRAE’s Advanced IAQ Design Guide Steering Committee

• “How to Produce, Label, and Select Sustainable Green Building Products,” Bob Thompson, U.S. Environmental Protection Agency (EPA)

• “Ozone and Implications Within the Indoor Environment,” Charles Weschler, University of Medicine and Dentistry of New Jersey

• “EPA’s Building Assessment Survey and Evaluation Study (BASE): Lessons Learned,” John Girman, EPA

The conference addresses what tools and metrics can be used to quantify buildings’ health and sustainability and how indoor air quality can be certified as sustainable. For complete conference information, visit

Publication date:07/30/2007