Attic Ventilation Fans Pros and Cons

Driving around any neighborhood and you’ll see them: little square objects lining the top of the roof line on most houses. Those are roof vents and they are an important component in keeping your home comfortable. Along with eave vents, roof vents provide air circulation and ventilation for your attic.

In the summer, the attic can get incredibly warm. Think of sitting in your car with the windows rolled up on a sunny August afternoon. Pretty uncomfortable, right? That also applies to an unventilated attic. Without those vents, that heat can get transferred to the rest of the house, making your air conditioner work that much harder.

But these vents can also help during the winter. If the attic floor is properly insulated and sealed from below, a vented attic can keep the temperature consistent with the outside. That means snow on the roof won’t constantly melt, refreeze, and cause ice dams. These ice dams can pull up shingles and allow melting snow to get to the underlayment, or worse, the decking.

What do attic fans do?

If your home wasn’t properly outfitted with roof vents, you may be considering a roof-mounted attic fan to expel the heat from the attic. These fans can be installed through the roof or near the peak of the roof on the back side of the home. Some are even solar-powered, requiring no wiring at all.

During the winter, these fans can also remove moisture from the air circulating in the attic. Any kind of moisture can be bad for the attic, causing mildew, mold, and other unhealthy conditions. These fans also prevent ice dams by keeping the attic temperatures consistent with the outside.

While attic fans provide the same kind of ventilation of roof vents, there are a few downsides. If a solar-powered fan won’t work for your location, you’ll need to hard wire one in. Also, if the house is “leaky,” the fan could actively be pulling warmer air from the home or other areas of the roof.

This defeats the purpose of having consistent ventilation from the outside. If the fan is hardwired and gets too much use, there may be no net savings in the energy bill.

Other Attic Considerations

The roof and the attic can work in concert to make your home more comfortable and even save you money. The answer depends on how you use your attic – is it a place for storage, a living area, or just a mystical place that no one ever goes?

There are a few ways you can control just how much of that heat seeps into your home or how much of the cool air escapes from it. If the attic is nothing more than a crawl space with exposed rafters, make sure there is the appropriate R-value insulation in place.

That alone can go a long way in keeping your home comfortable. Aside from making sure the eave vents aren’t blocked by the insulation, the use of vents or attic fan aren’t changed. The air is free to circulate, coming in through the eaves and leaving via the vents.

If the attic is conditioned and used as a living area, make sure the ceiling is properly insulated. There are a few ways to do this, either with roll out insulation or spray foam insulation. Check with an expert to make sure attic is up to code. You may not need venting at all.

With newer homes, codes demand a certain amount of roof vents as part of the construction process. And while adding a solar-powered or hardwired attic fan may provide some added relief, they may also work against the existing roof fans by drawing in outside air from the top of the roof, not at the eaves. That is why they need to be properly spaced, so they don’t pull from the upper vents.

In the end, the proper amount of roof vents should be enough to provide the correct amount of attic ventilation. Does your roof allow for enough ventilation? Give us a call. In addition to roof repair and installation, we can also inspect your roof to decide if more ventilation is needed.

Related Posts

Leave a Comment

Roof installation Warner RoofingUsed roofing hammer on new felt paper in horizontal format.