Attic Fan Vs. Ridge Vent

Maintaining proper ventilation in your home is essential to keeping a house cool, and avoiding problems like mold and rot in your attic and ice dams on your roof. However, you may not know whether or not you require an attic fan or if your ridge vents are doing the job.

For example, when your attic is large enough that the passive soffit and ridge venting are unable to effectively dispel trapped heat, an attic fan should be able to improve circulation. Additionally, if your roof’s design doesn’t include the right number of vents to keep up with the heat cycle in your home and there’s no good way to add more, an attic fan is the best solution.

Ridge Vent
For many homes, the right combination of ridge vents and soffit vents is enough to maintain proper ventilation. Ridge vents are located at the top of the attic and allow warm, rising air to escape. Soffit vents are located below ridge vents towards the bottom of the attic, usually under eaves, to allow cool, outside air to replace the hot, rising air. In many cases, people’s vents are placed right and doing their job, and in these cases, there is nothing more to do to ensure proper ventilation.

However, some homes aren’t designed well enough to allow for this natural ventilation to occur. For example, your attic may be very large and there may not be enough soffit vents to allow enough cool air to flow inside the attic to replace the escaping hot air above, resulting in poor ventilation. If this is the case, an attic fan may be the best way to improve ventilation and avoid all of the problems that arise with poor ventilation.

Attic Fan
Unlike a ridge vent, which allows warm air to passively flow out of the house through the top of the attic, an attic fan actively blows air out of the house. Attic fans use electricity to move air and improve ventilation in a poorly ventilated attic.

As mentioned, it’s important to make sure that your attic fan will not interfere with the cycle of air moving through the soffit vents to the ridge vents. If not done properly, attic fans can make your ventilation worse by either pulling in more hot air or blowing out cool air.

So when should you use an attic fan?
Attic fans should be used when your attic is too large for the number of soffit and ridge vents, making for poor ventilation in your attic and improper air circulation. You should consider using an attic fan when you inspect your attic and find that your ventilation needs improvement.

However, know that if you’re trying to use both ridge venting and an attic fan for ventilation, you need to make sure the attic fan isn’t operating near your existing ridge vents or you could end up making the problem worse.   If you find that you would benefit from using an attic fan, then install it away from the ridge vents to eliminate any possibility of interference.

An attic fan should greatly improve your ventilation throughout your house, not only keeping it cooler but keeping your attic and roof in better condition.