“Ventilate” comes from the Latin word for “to fan,” the action of causing air to move.
And thats exactly how ventilation works. It provides the conditions that allow air to move.
Most Homeowners believe that the purpose of the attic ventilation is to remove heat that builds up in the summer. That’s accurate, of course. But what that answer leaves out is as important as what it includes. An effective ventilation system provides year-round benefits.
Helps Reduce Energy Consumption
During warmer months, ventilation helps keep attics cool. Radiant heat from the sun warms the roof and radiates into the attic. If not properly vented out, it can radiate into the house affecting he comfort level in side the house and contributing to higher utility bills. The reduced temperature in your attic will help keep the ductwork and air inside your home cooler. The resulting effect are going to be a reduced strain on your air conditioning unit. During colder months, ventilation reduces moisture to help keep the attic dry.
Protects Against Damage To Materials And Structure
The shingles and decking of your roof system may deteriorate prematurely because of heat and excessive moisture buildup. By reducing the surface temperature of the shingles and therefore the existence of moisture on the underside of the decking by properly ventilating the attic space, a home-owner is also able to extend the life of both these materials.
Defends Against Ice Dams
Winter created a special attic ventilation problem in areas where snowfall and cold temperatures are common occurrences. The problem begins with the formation of ice dams which prevent melt water from running off a roof. Ice dams can form when warm air from the house accumulates within the attic, lower areas of the roof remain cold and a snow cover accumulates on the roof. The melted snow flows down the roof until it reaches a colder spot, like the eaves, where it refreezes, forming a back up of ice commonly called an ice dam. A properly designed ventilation creates a “cold roof” - a condition where the roof temperature is equalized from top to bottom, which helps eliminate the conditions that lead to the formation of ice dams. Roof damage occurs when the water pooling against the dam begins to back-up under shingles. Plus, water can infiltrate into both exterior and interior walls, resulting in rotted roof decks and rafters, ruined insulation, moisture inside the walls, mold and peeling paint, which could cost a home-owner many dollars or more to repair.