How does direct sunlight affect attic heat load? 

The solar attic fan operates more efficiently when it receives direct sunlight. For south-facing solar panels, this typically occurs between 11:00 AM and 4:00 PM, when your roof absorbs about 85% of its total daily solar radiation.

During this period, if your fan is properly sized and installed, attic temperatures should average about 5–15°F above the outdoor air temperature. After peak sunlight hours, the fan slows as solar intensity decreases. You may notice a slight rise in attic temperature at this time, but this is normal. Your attic insulation is designed to manage any residual heat load as the day cools down.

If you observe attic temperatures consistently more than 15°F above ambient during midday, please contact us. Our team will review the system sizing to ensure your installation is optimized.