Roof Louvers
These are also referred to as slant backs, box vents, and turtle vents. They are metal or sometime ridged plastic vents that have a small chimney in them that is covered in a way to prevent water and snow from entering. They exhaust by simply letting the hot air naturally rise out of them.
Ridge Vents
There are many different types of ridge vents on the market some are better than others at exhausting but they basically all work the same way. A gap is cut in the center of the ridge (top) of the roof, a ridge vent is them put over the top of this area and through a series of baffles lets air out and prevents water and rain from coming in. The hot air will naturally rise to the ridge and come out but a ridge vent will also pull the hot air out with the aid of air movement over the top of the roof. The roof itself acts like an airplane wing and as air moves over the top of the roof it creates negative pressure that will suck the hot air right out of the roof. The other benefit of ridge vent is that it is shingled over and is hardly noticeable when compared to box vents.
Turbines
Sometimes called whirly birds these vents are usually installed right under the ridge of the roof, usually towards the back of the home so they can not be seen as easily. They are spun by wind moving over the roof and the same spinning motion creates a negative pressure that pulls the air out of the attic. Their benefits include not needing as many vents to properly ventilate, and they only require natural outside air movement to work effectively. A few draw backs include their bulkiness which it not astatically pleasing, they are also susceptible to damage and wear out overtime.
Power Vents
These vents are basically electric fans that pull hot air out of the attic. They must be wired in most cases and they run off household electricity. An adjustable thermostat dictates when the fan turns on as the temperature in the attic rises. These vents can also be bought with an optional humidistat that will turn on when humidity levels increase, which is beneficial when temperatures are low but humidity is high. These vents work well on roofs where there is not enough ridge room for traditional forms of venting. The obvious draw back is these vents require electrical power to operate, so they cost money to be effective. When installing these vents one must make sure there is proper soffit ventilation or the vents will pull make up air from inside the house.
Gable Vents
These vents do not sit on the roof but rather in the gables. Many homes built around the 50’s and 60’s in Western Nebraska have this form a ventilation, and it is still used today. In some cases it works fine but in some situations it can be problematic or ineffective.
