Enter your attic fan's CFM rating and wattage to size the right solar panel and see how ventilation can cut AC load.
A common rule of thumb is 1 CFM of ventilation per square foot of attic space — solar attic fans run directly off their own dedicated small panel, separate from your main home solar system.
Attic fans run hardest exactly when the sun is strongest — hot, sunny afternoons — which makes them one of the cleanest matches for a small dedicated solar panel with no battery needed. Better attic ventilation reduces heat buildup that would otherwise transfer into living space, indirectly lowering the load calculated in your HVAC sizing or AC running cost.
No — since it only needs to run while the sun is out (exactly when attic heat buildup is worst), most solar attic fans run directly off the panel with no battery or inverter required.
The common guideline is roughly 1 CFM of airflow per square foot of attic space, though steep or complex roofs, dark shingles, and hot climates can push that recommendation higher.