Learn How to Create a Fresh Air System in Your Home

All houses need an efficient way to exhaust stale, moist indoor air and introduce outdoor air. Additionally, good ventilation makes a house healthier for occupants and protects the building structure from moisture damage. Traditionally, homes rely on natural ventilation and infiltration provided by air exchange through random gaps and cracks in the building shell. As a result, the occupants control ventilation in these homes via windows.

Additionally, the amount of fresh air from natural ventilation depends on wind speed. Plus, any temperature differences between indoors and outdoors. A home with natural ventilation usually contain too much outside air in the winter. This results in high heating bills and uncomfortable drafts. Finally, on mild or calm days in other seasons, these homes often lack ventilation.

Houses built today are tighter than houses of 50 years ago, while the number of pollutants in the home continues growing. Moisture, pets, furnishings, cigarette smoke, aerosol sprays, household cleaners, paints, carpets, fireplaces and woodstoves all can add to indoor air quality problems in the tighter homes we live in today.

Fresh Air System Standards

The most common standard for bringing fresh air into our homes today is called ASHRAE 62. (ASHRAE develops guidelines and standards for engineering design, building practice, and building codes throughout the United States.) ASHRAE Standard 62- 2016, Ventilation for Acceptable Indoor Air Quality, requires mechanical spot ventilation for specific sources of indoor pollutants. It also requires general ventilation to maintain indoor air quality. The overall tightness of the home, the number of occupants in the home and the total conditioned volume of the home determines the amount of general ventilation required.

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