Homes are under constant pressure differentials which will draw air into the home or push air out of it, which creates a natural effect known as the stack effect. Leaky homes create a stronger stack effect than tight homes. We recommend making the home as tight as possible and controlling where new air is introduced. Controlling air flow is not only energy efficient but it also helps control moisture intrusion, high humidity, low humidity, dust, pollen, mold, and prevents rodents and pests from entering the home.