A thermosiphon system is a passive solar water heating method that uses natural convection to circulate water between solar collectors and storage tanks without mechanical pumps. Hot water naturally rises while cooler water sinks, creating continuous circulation driven entirely by temperature differences. These systems are simple, reliable, and require no electricity to operate.
Technical Details
Thermosiphon systems must position the storage tank above the solar collector to maintain proper natural circulation. The temperature difference between the heated collector water and cooler tank water typically creates flow rates of 0.5 to 1.5 gallons per minute. No moving parts mean lower maintenance requirements and extended system lifespan of 15 to 20 years.
Applications and Practical Significance
These systems work best in mild to warm climates where freezing is unlikely, making them popular in southern regions and tropical areas. They are cost-effective for residential applications with modest hot water demands, costing 20 to 30 percent less than active systems. The lack of pumps and controllers makes thermosiphon systems ideal for remote locations without reliable electrical service.