What should be provided to equalize pressures in a crawl space?

The proper method to equalize pressures in a crawl space is to provide a pressure relief duct to the house interior. This approach allows for adequate air exchange between the crawl space and the main living area, effectively balancing the air pressure. When pressure differences exist, it can lead to moisture issues, odors, and potential structural damage. By facilitating airflow, the pressure relief duct helps to equalize the pressure and maintain a healthier environment in both the crawl space and the living areas above.

While additional vents at the exterior may seem like a valid option, they do not directly address the need for pressure relief into the house interior. Sealing all openings tightly can trap moist air in the crawl space, leading to more significant issues, particularly in humid climates. Similarly, a sump pump is primarily used for water management and does not address the air pressure dynamics essential for preventing moisture buildup and ensuring proper ventilation throughout the space. Thus, the use of a pressure relief duct is the most effective solution for equalizing pressures in a crawl space.