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House interiors build up heat and moisture, especially in the attic.
Keeping the attic dry andwell-ventilatedis important for preventing mold and for preserving the lifespan of your shingles.
A ridge vent and anattic fanare additions that can ventilate and cool down attics.
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Unlike attic fans, ridge vents are passive, not mechanical, ventilation devices.
Next, cap shingles are often installed over the ridge vent for better appearance.
Some ridge vents do not need cap shingles.
Since heat rises, ridge vents let attic heat escape where it matters the most: the very top.
Wind reaching the house from either direction can flow into the attic, though to a limited degree.
Attic Fan
Anattic fancan be located either vertically on the home’s gable or on the roof.
When the fan is on the gable, the fan mechanism is entirely in the attic.
Part of the fan is on the roof and part is located inside theattic.
Ridge vent material comes in coils that are unrolled along the length of the slot.
Ridge vents are often finished off with cap shingles that match the roof shingles.
Cap shingles are left open on the side to keep the vents exposed.
Anatticfan can be installed relatively easily in a house’s gable.
With both types of attic fans, power is always necessary.
Appearance
Ridge vents blend in well with the roofline.
Even with added shingles, ridge vents are barely more than 1 inch high.
Since they follow the roof ridge, they are not usually visible.
Roof-mounted attic fans are visible and can be obtrusive, especially if more than one is installed.
No motors are needed for operation.
Attic fans have motors and are electrically powered.
Most attic fans run off of 120V power.
A 2,860 cubic foot per minute (CFM) attic fan can draw as little as 157 watts.
So, while attic fans do require electricity, the power draw is low and operation is only intermittent.
Which Should You Buy?
In this scenario, the ridge vent passively handles ventilation and cooling duties until it reaches its full capacity.
Then, the attic fan takes over.
Attic fans in the $300 to $400 range can move upwards of 5,000 CFM.
For lower capacity ventilation at a steep cost savings, a ridge vent might be your best choice.
Sixty feet of plastic ridge vent costs $100 to $200.
Roof Ventilation.2018 International Residential Code (IRC).
