Attic ventilation is an important consideration in any home. Keeping air moving is not only healthier; it also helps keep the interior climate of a home balanced. Probably the most significant aspect of good attic ventilation is moisture prevention. |
Unfortunately, truthful information is often overlooked in favor of interesting "old wives tales" that seem to pass from one generation to another. The truth is much more valuable when trying to obtain the proper air circulation for a home with roof ventilation systems.
Attic circulation is often the least well-managed indoor air component with as many as ninety percent of all households having improper ventilation. Moisture in a home not only causes damage to the structure itself; it creates an unclean air environment that can contribute to numerous health problems. Medical issues such as asthma, viruses and other air-borne illnesses and allergens including dust, mold and other particles are common in homes with poor attic circulation which should be remedied to keep all occupants healthy.
Part of the reason why so many homes have such poor circulation is that most people do not understand how the entire air movement process works. Many well-meaning, health-conscious individuals have worsened indoor air quality by following suggestions that are not grounded in fact - only to learn that a child's ongoing asthma and bronchitis or the water stains on a ceiling result from the lack of proper air circulation in a home's attic.
Following are a few things to keep in mind when considering proper attic ventilation:
Vents or Outlets - Roof vents are essential for good attic circulation. They do not allow for heated air to escape through the attic, since there is no actual heat delivered to the attic through the heating system. Outlets in a roof help to keep attic air moving, allowing for any moisture to evaporate before causing a problem. Under floor ventilation is also essential.
Formula - There is a correct amount of air movement that a house should have. The formula for figuring this is generally about 1:300, meaning one square foot of air moved for every three hundred square feet of ceiling space. Having too many openings does not help the issue and may actually make it worse. The proper amount of ducts allow for the right amount of air to be drawn in and out through natural resistance.
Variables - Another important point about roof vents is that there is not one type appropriate for every home or location. There are many variables that affect whether or not ducts actually do any good in a particular application; arguments about which type is better are mostly moot for this reason. Each kind will work, but none of them work perfectly. In the worst situation where proper balance cannot be achieved, attic fans can be installed.
For an idea that seems so simple - opening up space to allow for circulation within an attic space - it is actually very complex and false assumptions about air circulation have been created by fables that seem to self-perpetuate. Getting a formula just right in order to create the perfect amount of air movement and ventilation can be complicated - but it is certainly not something that should be relegated to what a neighbor's uncle's cousin thinks will really work.
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