Solar Attic Fan Info Center: Solar Attic Fan Information

Easily installed and free to operate, solar attic fans are a smart choice for homeowners who want to save money cooling their homes in summer, prevent ice dams in winter, and extend the lives of their roofs.

Solar Attic Fan Operating Principle:

A solar attic fan uses photovoltaic panels to convert sunlight into electrical power. The electricity generated is used to turn a fan motor, exhausting air from the attic of a home.


In summer, temperatures in an unventilated attic can exceed 160 degrees F. A properly sized solar attic ventilation system will reduce attic temperature to 5-10 degrees F above the outdoor temperature. Ventilating the attic reduces the amount of heat transferred from the attic to the home, decreases the load on the air conditioning system (reducing your electric bill), and extends the life of the roof.

In winter, heat trapped in the attic may melt snow on the roof, which trickles down and creates destructive ice dams in the colder eaves.

The attic becomes warmest when the sun is the strongest. A solar attic fan runs the hardest when the sun is strongest. Everyday home activities such as cooking and showering create moisture which collects in the attic and promotes mold and mildew growth, reduces the effectiveness of insulation, and attacks the wooden attic structure. Year round fresh air circulation from a solar attic fan removes this moisture and prevents moisture related problems. Zero operating cost.

Installation can be done by a handy homeowner. No electrician is required.

Quiet operation.

Things to Consider

• The cost savings due to reduced air conditioner load depends on the price of electricity in your area, the amount of attic space in your home, the efficiency of your attic insulation, and the amount of ventilation your solar attic vent is able to provide. A typical installation will usually pay for itself in savings within 1-2 summers of use.

• A solar attic fan should not be used when air from the living areas of the home can freely enter the attic. This would result in conditioned air being removed from the home. Any openings between the attic and the home should be sealed before a solar attic fan is installed.

• Properly sized attic vents are required to allow fresh air to enter the attic and replace the hot air removed by the solar attic fan.

• Solar attic fans should be mounted away from ridge vents and gable vents.


Solar attic fans are available in three configurations:

1. Self flashing roof solar attic fan: The fan base is flat and designed to slide under shingles and attach directly to the roof.

2. Curb mounted solar attic fan: The fan base is a cap designed to fit over a curb which is attached to the roof.

3. Gable fan: The fan exhausts horizontally through the gable end of the attic.

In addition, solar attic fans are available with fan mounted or remote solar panels.

Why do you need a Solar Attic Fan?

Solar attic fans offer an environmentally friendly and economical solution to summer time cooling problems resulting from attic heat penetrating your home's insulation. During the summer, attic temperatures can soar to over 150°F, keeping your attic hot throughout the day and well into the night. The higher the temperature of your attic, the less effective your attic insulation will be at stopping heat from entering your home.

Installation of a solar attic fan on your home minimizes the amount of heat entering through the attic by reducing your attic temperature. By minimizing the amount heat entering your home, you will save money on your summer cooling bill and make your house feel more comfortable (see diagrams below).

Solar Attic Fan Picture Details:
Solar Attic Fans - Details

Attic Without Proper Ventilation:
Solar Attic Fan Details

Attic After Installation of a Solar Attic Fan:
Solar Attic Fan Solution

Suppress Heat Build Up with a Solar Attic Fan:

A hot attic acts like a giant radiator, transferring heat into your living spaces, sending both utility bills and temperatures soaring. In colder climates, heat build-up in an attic causes snow to melt and run down where it freezes at the eaves, causing destructive ice damming.

Battle Moisture with a Solar Attic Fan:

Many of today’s houses have insufficient ventilation and air exchange. This causes high humidity levels from everyday activities. The moisture migrates through the ceiling towards the roof where it comes in contact with the cold structure. Here, ice and frost form, causing damage to your roof structure. Additionally, moisture can saturate insulation, promote fungal decay and plywood delamination.