They ve been well discussed here and other places but briefly they re not cost effective don t deal with the problem where it starts are using convection to solve a radiant heat problem and can even be dangerous by backdrafting combustion appliances and putting carbon monoxide in the home.
Cool attic static vents.
Granule coated aluminum slant back static roof vent in black.
This attic vent can quickly remove a larger volume of hot and or humid air from your attic when compared to static ventilation.
Air vent high efficiencypower attic fan 1470 cfm weatherwood galvanized steel electric power roof vent.
Air vent 1 500 cfm black galvanized steel electric power roof vent.
Galvanized steel static roof vent in black.
The effect of ridge vents for the roof depends upon the energy efficient nature of the structure.
Powered attic ventilators are the worst way to try to keep your attic cool.
Soffit vents may leave air trapped at the top of your attic.
The master flow erv4 power roof vent is a the master flow erv4 power roof vent is a great overall investment in attic ventilation.
Round duct in black steel.
For pricing and availability.
Ridge vents do not always provide the proper ventilation in some homes.
Cool air enters the attic through soffit vents in the eaves.
List of the cons of roof ridge vents.
This allows the incoming cooler drier air to enter the attic at the lowest possible location flush out any built up heat and moisture from inside the attic all along the entire underside of the roof deck and push it out through the exhaust vents high on the roof.
Duct or up to 8 in.
Once inside the air heats up and rises higher ultimately exiting through venting at the roof s gables through ridge vents cut into the roof s apex or other vent holes in the roof.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Roof cap with built in damper for 3 1 4 in.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
This method achieves the goal of air movement through the attic underneath your roofline.
If your attic is sweltering or your roof shingles are starting to crack or blister there s a good chance you could benefit from additional ventilation in your roof.
Dia keepa vent an aluminum roof vent for flat roofs.
The erv4 model.
Most homes already have some passive attic venting built in.
You ll be able to move air throughout the attic without the use of fans or turbines when enough space is given to this vent design.
Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof.