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If you’ve ever wondered if there is a difference in attic or roof ventilation or tried to compare Solar Attic fans and roof Turbines, we can help! There is a difference, and it can make a HUGE difference in the performance of your home.
Roof Turbines are a cheaper alternative to attic ventilation. They can perform like an “active” roof vent when the wind is blowing, or there is an excellent static pressure in your attic, but most of the hot months in Texas do not promote the spinning and performance of a roof turbine. It’s important for these “roofing eye sores” actually spin so they create the CFM or “cubit foot per minute” airflow they need to change your attic temperature.
Solar fans don’t require any electricity, wind, or attic pressure to spin. The sun does that! A solar fan is able to actively pull more air into your attic than a turbine can. A solar fan doesn’t rely on the wind, and it actually has a more powerful motor in it, so it keeps the temperature of your attic regulated regardless of wind conditions. Solar fans are a true “active roof vent”, and can lower your attic temperatures by up to 25 degrees!....might we add they look a bit better on your roof as well…
We often see multiple types of roof ventilation for one attic. Most of the time, this is not productive, as a ridge vent will compete with a solar fan, or a roof turbine will detract from a ridge vent. You should not mix active and passive ventilation systems. Also, an active roof vent should not be within 10-20 feet of a passive vent, if you decide to add or change your attic ventilation.
Air is like water or electricity—it’s going to take the path of least resistance. We want air to be drawn up through your soffit vents: the vents right under the eaves of your house. These vents allow air to flow into your attic. If you have a turbine right next to a ridge vent, the turbine won’t be pulling air into your attic from the soffit vents. Instead, they might be trying to cycle the air back and forth between each other. That doesn’t ventilate the attic!
If your roof already has a ridge vent and you would like to add a solar fan, we would most likely block off the inside of the ridge vent. The vent will still be there aesthetically, but we will block off the air flow so that the solar fan will pull the air in from your soffit vents. Most likely, when adding a solar fan, we look to replace an existing passive vent or roof turbine. We would look to block off any other roof vents within the 10-20 foot range, preventing the “cycling of air” at the roof level.