Ridge vent vs turbine vent: which is better?
Short answer. A ridge vent is usually the better choice: it vents continuously with no moving parts and little leak risk at the peak. A turbine, the spinning whirlybird vent, can move a lot of air when the wind blows, but it moves little on still days, its bearings wear and squeal, it dents in hail, and it should not share an attic with a ridge vent.
How turbines work
Wind spins the vanes, which creates suction that pulls air out of the attic. In a good breeze a turbine exhausts more air than a static vent of similar size. When the air is still, it behaves like a static vent.
Comparison
- Consistency: ridge vents use rising warm air plus wind; turbines lean heavily on wind.
- Moving parts: turbine bearings wear out, and a wobbling head can squeal or work its flashing loose.
- Weather: turbines are tall, thin metal, so hail dents them and high winds can bend them. After Georgia hail they are often among the first items an adjuster notes.
- Appearance: turbines are visible from the street; ridge vents sit low.
- Short circuit: a turbine near a ridge vent pulls air in through the ridge.
Replacing turbines during a reroof
If your roof has turbines and a ridge long enough to meet the exhaust need, the common upgrade is to remove the turbines, deck over the openings and install a ridge vent. If the ridge is short, turbines can be replaced with new units or static vents of adequate net free area. Either way, soffit intake has to keep up.
More in ridge vent vs box vents and Georgia hail season. Robust Roofing explains what hail does to vents and shingles on its hail damage roof page.