AIVC Technical Reports

Residential Passive Ventilation Systems: Evaluation and Design Doawnload the full document 1 MB

A Critical Evaluation of the Potential for Adapting European Systems for use in North America and Development of a General Design Method

James W Axley
AIVC Technical Note 54, 2001, 158 pp, Code TN 54

Infiltration has long served the residential ventilation needs in North America. In Northern Europe it has been augmented by purpose-provided natural ventilation systems - so-called passive ventilation systems - to better control moisture problems in dwellings smaller than their North American counterparts and in a generally wetter climate. The growing concern for energy use, and the environmental impacts associated with it, has however led to tighter residential construction
standards on both continents and as a result problems associated with insufficient background ventilation have surfaced.

Recognizing the energy penalty of uncontrolled natural ventilation, building researchers and practitioners in North America are turning to mechanical systems to provide the necessary ventilation for air quality control. Northern Europeans are following suit but have not completely abandoned the passive ventilation methods that have served them for the past century. Research programs have been initiated in Britain, The Netherlands and France, in particular, to improve the
understanding and performance of these traditional and largely empirically-based ventilation methods in the hope that they can more reliably provide basic background ventilation while avoiding the energy penalty associated with uncontrolled over-ventilation.

This state of affairs begs, then, a simple question:

Can European passive ventilation systems be adapted for use in North American dwellings to provide ventilation in an energy conservative manner?

This Technical Note attempts to answer this question. The configuration, specifications and performance of the preferred European passive ventilation system - the passive stack ventilation (PSV) system - will be reviewed; innovative components and system design strategies recently developed to improve the traditional PSV system performance will be outlined; and alternative system configurations will be presented that may better serve the climatic extremes and more urban contexts of North America. While these innovative and alternative passive ventilation systems hold great promise for the future, a rational method to size the components of these and other systems to achieve the control and precision needed to meet the conflicting demands of new ventilation and airtightness standards has not been forthcoming. Such a method will be introduced in this Technical Note, based on a review of existing simulation and design methods, and a series of applications of this method will be presented. Finally, provisions of the new International One- and Two-Family Dwelling Code that are likely to relate to the installation of passive ventilation systems will be reviewed and proposals for changes to this code will be put forward.

Contents

  • Introduction
  • Review of European passive ventilation methods
  • Alternative passive ventilation options
  • Analytical methods - simulation and design
  • A first-order design method based on loop equations
  • North American construction and dwelling codes
  • Conclusion
  • Bibliography
  • Appendix: Additional design examples
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