Tuesday, January 31, 2017: 9:45 AM-11:00 AM
Commercial and Industrial IAQ
Chair:
Jordan Clark, Ph.D., CPP Wind Engineering and Air Quality Consultants
Technical Committee: 4.3 Ventilation Requirements and Infiltration
Sponsor: SSPC 62.1
Natural ventilation offers the promise of more energy efficient, healthier, and more productive commercial buildings. However, most designers and code compliance officials are in agreement that the current prescriptions for natural ventilation contained in ASHRAE Standard 62.1 are inadequate. This session presents some of the work being done by the members of the Natural Ventilation Working Group under SSPC 62.1 in order to open up discussion on potential standard changes to the greater ASHRAE community and present original research done by the group's members.
1 What Climatic Conditions and Building Parameters Identify a Commercial Building as a Good Candidate for Natural Ventilation?
One barrier to adoption of natural ventilation is the knowledge that application in inappropriate climates or during inappropriate hours could lead to conditions in buildings which may affect both comfort and IAQ. As such, designers must diligently determine whether a climate is appropriate for natural ventilation. A series of tests on the typical meteorological year weather data can be used for this purpose. For many US climates, even mild climates, under normal design conditions, natural ventilation alone may not assure occupant satisfaction. In most cases, spaces may be advised to use mixed-mode ventilation systems, which combine natural ventilation and mechanical ventilation.
2 Review of Indoor Air Quality Considerations for Naturally Ventilated Commercial Buildings
Natural ventilation can provide fresh air for a building and is one strategy for reducing building energy demand while maintaining or improving indoor air quality. However, there exists uncertainties regarding implications of naturally ventilated commercial buildings with respect to indoor air quality. This presentation summarizes a review of the state of building codes and standards, case studies, and research literature regarding the application of natural ventilation to commercial buildings with specific attention to IAQ objectives, including: i) air pollutants of concern, ii) modeling approaches, iii) prescriptive approaches, and iv) new directions for improving IAQ in naturally ventilated buildings
3 Using Facade Pressures to Predict Wind-Driven Natural Ventilation Rates
Two often overlooked but crucial parts of the design process for buildings wanting to take advantage of wind-driven natural ventilation are 1) obtaining accurate facade pressures, and 2) using them in such a way as to accurately predict the amount of air which will enter a space. Through a review of extant sources and presentation of new research, this presentation looks at the various methods for obtaining and using facade pressures and discusses strengths and weaknesses of each.
4 Natural Ventilation Design Incorporating Moisture and Air Velocity Control
Natural ventilation in buildings has been around for many years, Robert Boyle provided a description on how to design such a system in the 1800’s. Today's current trend of incorporating natural ventilation or a natural ventilation scheme into building design has led to a quest for a more detailed analysis of space conditions. This presentation presents some modern day applications of natural ventilation which also include space moisture conditions and analysis of air movement within a space.