Old Attic Pitched Roof Proper Ventilation

Whole house fans powered attic fans.

Old attic pitched roof proper ventilation.

Don t avoid ventilating your attic for fear you re letting cold air into the house. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Then aim for about 1 sq. The following are the requirements taken directly from the irc.

Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof. Baffles placed in this area channel intake air into either the attic space or vent chutes and also prevent insulation from falling into the soffit and blocking airflow. The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. Pitched roof ventilation is achieved by creating air changes in the attic.

In of vent opening per 150 sq. If not measure the size yourself. If there are asphalt shingles on your roof the attic must be ventilated to comply with the terms of the manufacturer s warranty. Roof ventilation is crucial to attics as it positively affects the home inside and out.

If the slope of your roof is greater than 6 12 you will need more ventilation to reflect the extra volume of attic space. Fans and vents may be installed on the roof system that will draw the air out of the attic space and exhaust it to the exterior. The success of a vented attic or roof deck relies on its airtightness. Your actual living space is sealed and insulated at the attic floor the attic is outside this envelope.

Calculate 20 per cent more for 7 12 to 10 12 pitches and 30 per cent more for a pitch that is 11 12 or greater. Intake vents located at the lowest part of the roof under the eaves allow cool. These fans may be controlled by a switch or a thermostat which detects heat build up in the attic space and automatically exhausts the attic space. Removal of excess heat and moisture will help the life of the roof and the efficiency of the hvac systems within.

The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area. The space above the top plate of exterior walls at the bottom of each rafter bay is especially important. Pitched roof ventilation is beneficial in all climate zones and in.