It is a scientific fact that heat rises, but when heat is trapped in an enclosed space, it will migrate in all directions, including downward. The heat of the sun bombards the attic of a house many hours a day. In areas that have extended summers, attic heat will begin to dissipate at night just in time for the sun to start rising again. As heat tries to escape, it will gravitate toward cooler temperatures in the interior of the house.
To solve this problem of attic overheating, some builders design attics with ventilation. Other builders disagree on the grounds that putting ventilation in the attic will simply invite more heat to enter. Homeowners may solve the problem by cranking up the air-conditioning. While this will provide an immediate solution, it doesn’t help in the long term. In fact, you could end up with an overworked air conditioning system and sky high energy bills.
The best idea is to provide ventilation under the roof assembly. Ventilation is an intake and exhaust system that makes airflow possible in an area. Opening up just one area will not create airflow. To observe this inside your house, open a window on one side of the home when it is hot and stuffy inside but breezy outside. You will not notice much of a difference in the air temperature inside the house. However, if you open a window on the opposite side of the home, you will feel airflow and, ultimately, lower temperatures inside.
To increase attic airflow, install both an intake and exhaust vent. Ventilation, coupled with insulating the attic using fiber blowing machines and other insulation blowing equipment, will help keep temperatures moderate and also prevent mold and mildew from infesting the attic.