Whole House Ventilation Strategies (January
2003, 23p.)
Whole-house ventilation is the process of supplying fresh
air to a living space and exhausting stale air, either by
natural or mechanical means in order to maintain an acceptable
level of air quality. Normal human activities such as cooking,
bathing, breathing, and maintaining houseplants introduce
indoor pollutants (including excessive levels of water vapor)
into the home. Additionally, building materials and furnishings
can contribute to indoor pollution through the out-gassing
of chemicals used in their manufacture.
Ventilation either dilutes pollutants (including excessive
levels of humidity) or flushes them from the home. Residential
construction traditionally has relied on infiltration to provide
ventilation. Infiltration is the leakage of air through the
building envelope through unintended gaps in walls, roofs,
windows, doors and other construction elements. Improvements
in construction, however, have resulted in more airtight buildings
and hence the need for dedicated mechanical or passive devices
to satisfy ventilation needs. Furthermore, infiltration has
been shown to vary with environmental conditions such as wind
and temperature differentials, and for significant periods
these driving forces may not be sufficient to achieve adequate
natural infiltration.
The purpose of this research was to provide a baseline for
evaluating whole house ventilation strategies for manufactured
homes. The report identifies research that needs to be done
in the future to update the foundation upon which recommendations
to the ventilation standards for HUD code homes are made and
guide the industry towards improved, more efficient, and cost-effective
practices to achieve the desired ventilation level.
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