Can You Use a Thermosiphon Without Electricity?

How Thermosiphons Work

A thermosiphon is a type of heat exchanger that uses the natural convection of hot water to circulate and distribute heat without the need for electricity. It consists of a coil or tube that is submerged in a tank of water, which is heated by an external source such as a wood-fired stove. As the water in the coil heats up, it expands and becomes less dense than the surrounding water, causing it to rise and create a circulation of water through the coil.

Designing a Thermosiphon for a Wood-Fired Stove

To design a thermosiphon for a wood-fired stove, you’ll need to consider the temperature of the stove coils, the volume of the water tank, and the height of the coil above the tank. Typically, the coil should be positioned at least 3-4 feet above the tank to create enough pressure to circulate the water. The coil should also be designed to withstand the temperature of the stove, which is usually around 200-300°F (90-150°C). For a wood-fired stove, a coil with a diameter of 1-2 inches (2.5-5 cm) and a length of 10-20 feet (3-6 meters) is a good starting point.

Integrating a Thermosiphon with a Stove

To integrate a thermosiphon with a wood-fired stove, you’ll need to attach the coil to the stove coils and ensure that the water tank is positioned below the coil. The coil should be suspended in the tank using a bracket or hanger, and the water level should be maintained at a level that allows the water to circulate freely through the coil. You can also add a batch heater, such as a 55-gallon drum, to the system to store excess heat and provide a reserve of hot water. By following these steps, you can create a reliable and efficient thermosiphon system that provides hot water without the need for electricity.