Can solar fans run at night or on cloudy days? How is their performance affected by weather?

Solar fans are designed to operate primarily during daylight hours, as solar panels directly power them. However, many systems incorporate a battery backup or a hybrid power option that allows the fan to continue running at night or during periods of low sunlight. On cloudy days, the output of solar panels is reduced—typically to 10% to 50% of their rated capacity depending on cloud thickness—which results in lower fan speeds. To compensate, Mail's solar fan systems are equipped with intelligent controllers that adjust the motor speed based on available solar power, ensuring continuous ventilation even in less-than-ideal conditions. For critical applications, we recommend selecting a system with adequate battery storage to ensure 24/7 operation.