Soffit and Eave Intake Vents
November 09 2020 Case Study Residential
Traditional homes, like the one pictured above, contain an overhang near the eave area where intake vents can be installed. The intake vents are the most important component to any roof ventilation system. As warm air in the attic rises, it exhausts through vents located on the upper part of the roof. The intake vents replace the warm air with cooler air in a process called natural convection.
The presence of intake vents increases the performance of a roof system in the following ways:
- Cooling costs are reduced and the living conditions are more comfortable as attic temperatures can be decreased by as much as 40%.
- Winter problems such as ice dams and condensation are prevented.
- Thermal expansion and contraction of the shingles is minimized, and the longevity of the roof system is increased.
Many homes in the Cincinnati area were constructed without an emphasis on energy efficiency or attic ventilation. These types of houses require a creative design in order to achieve proper attic ventilation. The house pictured above was built in Kenwood in the 1950s. The fascia board rests directly against the brick and traditional intake or soffit vents cannot be installed. In this case, we chose to install a product called the Smart Vent, which is illustrated below.
The roof was removed down to the roof sheathing and a 1 inch opening was installed on the roof deck to allow air to enter the attic space.
The Smart Vent is then applied to the gutter line. The product allows air to enter the attic at a rate of 9 inches of Net Free Vent Area per foot. The Smart Vent is tapered from top to bottom and blends in with the surface of the roof.
The roof underlayment (in this case Owens Corning WeatherLock ice and water shield) adheres over the Smart Vent.
The shingles and ridge vents are installed and the system contains a balance of intake and exhaust vents.
It is very important to make sure the air can flow unobstructed from the intake vents to the exhaust vents. If insulation or other materials are blocking the airflow, the system will not be efficient.
