All houses need an efficient way to exhaust stale, moist indoor air and introduce outdoor air. Good ventilation makes a house healthier for occupants and protects the building structure from moisture damage.

Traditionally, home builders have relied on "natural ventilation" and infiltration provided by random gaps and cracks in the building shell. The homeowner can control ventilation in these houses only by operating the windows and doors. Natural ventilation depends on wind speed and the temperature differences between indoors and outdoors. A house that "breathes" on its own often has too much ventilation in the winter, resulting in high heating bills and uncomfortable drafts. On mild or calm days in other seasons, the house often has too little ventilation.

Houses built today are tighter than houses of just 10 years ago, while the number of pollutants in the home has grown. Fireplaces, wood stoves, and other combustion appliances increase pollutant levels. Moisture, pets, furnishings, cigarette smoke, aerosol sprays, household cleaners, and hobby supplies add to the mix.

A well-designed mechanical ventilation system with good controls is important to provide consistent ventillation through all seasons of the year for all housing. Fans exhaust stale air. Leaks, passive inlets, or another fan draws in outdoor air. Maintaining good indoor air quality in a house requires reducing pollution sources and providing adequate ventilation to remove and dilute pollutants.

Call the professionals at the Snelling Company at (651) 464-7381 to get a free indoor air quality evaluation.