Good Indoor Air Quality

Good indoor air quality follows the Golden Mean:  not too hot, not too cold; not too dry, not too humid; not too breezy, not too still and a level of contaminants that is low enough so occupants aren’t getting sick.

These conditions will vary for different people.  Some folks are strongly affected by odors or pollens or other allergens that don’t affect others.  So, good indoor air quality for you might not be exactly the same as good indoor air quality for me.

There are, however, certain basic requirements for good indoor air that seem to hold true for most of the population.  Dampness is crucial.  The current guidelines recommend home humidity should be below 60%.  Many consultants are pushing for lower and lower humidity levels to be maintained in homes. 

The contaminants that we create by living in our homes need to be diluted by sufficient fresh, outdoor air.  Since outdoor air frequently is not at the right temperature or humidity for our homes, it has to be conditioned (heated or cooled and dehumidified) to make us feel comfortable and to keep the house dry.  Contaminants that we bring in from the outdoors can be filtered out.  The same can be said of indoor contaminants like dust and pet by-products.

Since we frequently can’t introduce enough fresh air to dilute the contaminants we create, it’s often a better solution to remove the contaminants where they’re created.  So, good exhaust fans vented to the outside remove moisture, particulates and odors in bathrooms, laundry rooms, kitchens and garages.

Another contributor to good indoor air quality is to reduce the contaminants we create: source control.  If you don’t put the contaminant in the house, you don’t have to dilute or remove it. 

According to the U.S. EPA, "There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution."

Trudy Y. Smith
Senior Training Specialist
Spruce Environmental Technologies and HomeAire