Concerned homeowners are looking for cost-effective ways to reduce utility bills while increasing the comfort of their homes. Working in tandem with insulation, attic ventilation helps to maintain comfort levels and reduce energy consumption. An under-ventilated attic may exceed 150 degrees Fahrenheit in the Summertime, and become a mold-breeding place in the cool of Winter. Effective attic ventilation provides year-round benefits and helps the attic’s insulation work more efficiently.
Inadequate attic ventilation is an often-overlooked cause of maintenance issues. Some of the warning signs include heat radiating from the ceiling or attic access, peeling paint on the ceiling, and hot air blowing from the air conditioner ducts. Excessive attic heat is known to cause melting of plastic junction boxes and plastic wire nuts, causing fire hazards. Hot spots within the attic may cause buckling of shingles. Proper ventilation is considered to be such a critical factor that major manufacturers of roof shingles void their warranties if adequate ventilation is not provided.
Air circulation is created with intake vents placed low in the attic and exhaust vents near the peak of the roof. Intake vents allow cool, fresh air to enter the attic, where it mixes with the warm, moist air, which rises to the peak to be exhausted. Hip roofs almost always need additional insulation.
If the homeowner finds that the existing passive system is not promoting enough airflow, the first step is to check that soffit vents are not clogged with insulation. This is easily accomplished by being in the attic with the lights off and looking for sunlight coming through the soffit vents. If the homeowner finds that there is still inadequate airflow, active powered ventilation is a reasonable choice.
There are two types of powered attic exhaust fans, electric and solar. If the back of the house faces north, and has a pitch of 9:12 or greater, electric attic fans will be the only choice. If the back of the house is shady throughout the day but the front of the house is sunny, again electric fans would be needed to provide active ventilation. No attic fan should be placed too close to a gable vent or ridge vent without blocking it, as they will short-circuit the air flow.
Many homeowners complain that electric fans are noisy, cost too much to operate, and are prone to motor burnout. Solar-powered attic fans are now available that are silent, cost nothing to operate, and are both durable and reliable.
The solar panel collects sunlight and converts it into power that drives a d/c (direct current) fan, pulling air out of the attic to protect it from heat and moisture. Today’s thin film technology, developed by SunRise Solarâ, has produced attic ventilation fans in various sizes which are responsive to ambient sunlight and can move 850 to 1250 cubic feet of air per minute. Because the solar fans cost nothing to operate and reduce the burden on the air conditioning system, each will pay for itself in about 2-1/2 years.
Not all solar attic fans are created equal, and there are sub-standard versions on the market. Homeowners should look for an integral solar panel, a metal fan blade, durable critter-proof housing, and a history of satisfied customers. |
