Why ventilate? Proper attic ventilation protects a home from damage…
With the many issues to be solved during design and construction, it’s not surprising that attic ventilation can be overlooked. And that’s a problem. Because without effective attic ventilation, heat and moisture can build up in the attic, causing serious problems with costly consequences.Heat and moisture can build up, causing the roof structure, shingles and paint to deteriorate prematurely.
That’s why most shingle manufacturers require ventilation to validate their shingle warranties.Excessive heat can radiate into the living areas, making rooms uncomfortable and making air conditioners work harder. Ventilation helps reduce moisture buildup that can cause mold and mildew. An under-ventilated attic in the winter is a major cause of destructive ice dams.
A ridge vent is positioned along the entire length of the roof peak. In addition to being excellent exhaust vents, ridge vents blend in with the roof line, making a more attractive home. Years of research has proven that ridge vents with external baffles, combined with undereave venting, is the most efficient and effective system you can install.
Gable & Wall Louvers
Gable louvers are installed in the gable end of the attic. The higher these vents are placed, the more effective they become as exhaust vents. Gable louvers are not a preferred method of ventilating an attic because they provide only limited air flow across the underside of the roof deck, resulting in “hot spots.” They are also dependent on wind direction. Gable vents get their name because they are located in the triangular sections, or gables, on the ends of certain types of roofs. Styles include rectangular or triangular designs that can add a decorative look to the gable end.
Turbine vents protrude from the roof and use a series of specially shaped vanes to catch the wind and allow the turbine to spin, pulling air out of the attic. Although not as effective as ridge vents, turbine vents provide a low-cost alternative in areas where consistent wind speeds of at least 5 mph are typical. Without that minimal wind speed, turbine vents act essentially as roof vents.
...read more about wind turbines
Roof louvers are covered openings that allow air to escape the attic. Most attics require several of these vents to be installed to properly ventilate the attic. They should be placed evenly across the roof. Roof louvers only provide a small, confined area of movement, which means air does not move along the entire undersheath of the roof deck. And because multiple holes must be put in the roof, most people try to avoid roof louvers.Versatile styles include metal or plastic in round, square or slant-back designs.All exhaust vents, for example roof louvers, should be balanced with proper intake vents.
Power Attic Ventilators
A power ventilator is a motor-driven fan that is controlled by a thermostat. It works quickly to pull air out of the attic. A humidistat is also required if you want to control winter humidity problems. Some power fans can move as much as 1,500 cubic feet of air per minute. To ensure adequate ventilation, power fans must provide at least 10 changes of attic air every hour. With balanced motor and blade design, Attic Aire™ power vents quickly exhaust heat or humidity from any attic. They work on a thermostat, which turns the fan on automatically when cooling is needed. The All-Season™ model also has a humidistat that monitors the humidity level.
Whole House Fans
Whole-house fans cool and circulate air by pulling fresh outside air into your home. Your open windows act as intake “vents,” varying the air flow depending on how many windows are opened. The air is pulled in and circulated through your home, pushing the stale, overheated air into your attic. It is especially important that your home have adequate exhaust vents so that this air can be vented out of the attic.Even if your home has an air conditioner, you may want to install a whole-house fan. The fan helps your home feel cooler much faster, and can help cut your cooling costs....read more about whole-house fans
Whole-house fans are mounted in the attic above a central hallway and draw cool, outdoor air into the home. Belt-Drive Whole-House Fans
• Motor mounted just above and to the side of the fan
• Smoother, quieter operation than direct-drive models.
- Continuous Soffit Vents – For intake venting, made in plastic or aluminum, these vents install in your soffit or eave areas.
- Eave Vents – For intake venting at the eaves, available in white, brown or mill finish. Individual eave vents should be installed between each rafter.
- Drip Edge Vent – Combines a drip edge with intake vents for homes with little or no soffit. Drip edge vents install behind the gutter