Proper attic ventilation helps prevent heat build-up in the attic, which can lead to several problems, including higher energy costs and roof damage. By installing a fan in the attic, you can keep your home cooler, protect the outside of the house and lower your energy bills. Bottom line: DO NOT use electric ventilation grilles in the attic if the goal is to cool your home. CONSIDER IT as a possible option to extend the life of your roof, provided they are properly installed.
To prevent mold and damage to the attic, you'll need it to be cool and dry, and ventilation grilles in the ridges are the best option for this. They work by means of passive ventilation, which basically means that they don't use electricity to remove hot air and bring in fresh air through the ceiling ventilation grilles placed around the edges of the ceiling. They won't make the roof last forever, but attic fans can reduce wear and tear, improving years of roof use and delaying expensive replacement costs. The gable mounted fans, which are placed in the attic's gable vents, are also fantastic; they combine with the ventilation grilles in the house without affecting to the ceiling.
However, when used for their intended purpose (reducing heat in the attic to prevent premature roof deterioration) they are a valid option, provided they are properly installed and in combination with the appropriate amount of intake ventilation. Whole-house fans are a better way to clean an attic, but they won't help much in reducing an attic's heat load if the roof is insulated. By keeping the attic temperature below the sweltering temperature, the attic fan can help keep the roof in optimal condition and reduce the risk of structural damage caused by moisture accumulation. Many people do not know that a poorly ventilated attic accelerates the aging of tiles and deforms the wooden coating of the roof.
Attics change a lot depending on their size, the climate in their area, the slope of the roof, and the types of air systems being used. One of the most common reasons for a bad experience with attic fans is that the installations are poor, causing leaks and damage to the roof. It can help reduce condensation in the attic and ice build-up on the roof in cold climates, but Florida doesn't have that problem. One of the main advantages of attic fans is that they help maintain the integrity of asphalt roof tiles to delay deterioration and prevent them from deforming.
In addition, some type of vapor barrier (sheet insulation with kraft paper backing, with the paper face down) must be installed between the ceiling beams and the attic floor (if present). Ceiling-mounted attic fans are usually easier to install and can ventilate the attic space right away. The house is a one-story house above ground (mostly) from the early 1950s, with a very low attic (mezzanine height) in one part of the house and a beamed ceiling finish (no attic) in the other parts. However, even if the two fans bring in and out equal amounts of attic air, there's no guarantee that the exhaust fan isn't drawing some air out of the house and the supply fan isn't pushing some hot air from the attic into the house.
