Fresh air in the attic space of a home is essential for preserving the wood and insulation that supports the roof and protects the home’s interior. When moisture is allowed to stay in the attic through multiple temperature changes, the condensation will collect on the wood and allow mold and mildew to form. Traditional attic fans require electrical wiring and a switch to turn on the fan. Most of these electric fans are controlled by a thermostat that is set to 125 degrees, so the fan will not run until the attic temperature is very hot. Another approach to ventilating the attic is to install a solar powered attic fan.
How a Solar-Powered Attic Fan Works
When a solar powered attic fan is mounted near the ridge of the home’s roof, the maximum air movement can be achieved. Summer and winter ventilation is important for humidity control in the attic space. Most units have the solar panel mounted to the fan, but gable-mounted units are available. A shingle roof will require a self-flashing unit to shed water in line with the shingles. Solar-powered attic fans are easy to install because:
- No electrical wiring needed – Since the solar powered attic fan is a complete unit, there is no need to string an electrical connection to the unit. This makes installation much easier on a roof of any size. A large attic might require multiple units, but each unit will run from the power generated from its solar panel. Larger fan units will have a larger solar panel that will generate sufficient electricity for that specific unit.
- Automatically runs – As long as the sun is shining on the solar panel, the fan will run and pull air up through the gable vents while expelling the air through the fan vents. Cloudy days and shade from trees will prevent power from being generated by the solar unit. Some people choose to install a thermostat on their solar powered attic fan to prevent it from running during the colder months.
Advantages of Installing a Solar-Powered Attic Fan
Even though building materials are more advanced than ever before, there are definite benefits to the home that will be realized by the homeowner after a solar powered attic fan is installed. Very large attic spaces might require multiple units mounted at the right points on the south-facing slope of the roof. If the sun is not on the roof of the home, there are units that can be separate from the fan so the panel can be mounted in the sunshine. Each fan includes the optimal solar panel to provide the necessary power to the motor.
- Cools attic space – During very hot weather, the attic temperature can soar to 165 degrees. Even if the attic has sufficient insulation, that heat will radiate into the upper air space in the home. A solar powered attic fan runs during the sunny hours of the day, and pulls the air out of the attic.
- Relieves load on air conditioner – Since the attic is cooler, the air conditioning unit that is meant to cool the home’s interior will not have to work as hard. Cooler air in the attic translates into less radiated heat near the ceiling of the upper floor.
- Removes moisture – Humidity collects in the stale air in the attic of most homes. A solar powered attic fan will create a steady draw on the attic space, which removes the moisture. Summer and winter attic air will be refreshed whenever the sun is shining.
- Reduces condensation – When hot air cools, the moisture in that air will condense and collect on the wood and insulation in the attic. A properly-sized solar-powered attic fan will reduce the amount of moisture in the attic space so the condensation is reduced.
- Prevents growth of mold and mildew – Moist wood and insulation is the perfect setting for mold and mildew to grow. A solar-powered attic fan will vent the moisture from the attic and upset the natural cycle of mold growth.
Final Evaluation
Humid climates present challenges to the homeowner that can be addressed with the simple installation of a solar-powered attic fan. Well-built units can last for years and provide steady air flow for the attic space of almost any home. Care must be exercised to ensure that the fan unit selected can be mounted on the roof materials on the home. Air flow is an important factor regardless of the weather outside since moisture presents a real threat to the attic contents and structure.