wood stove fan

self-powered stove fan

Model 802 Ecofan self-powered stove fan.

A wood stove fan is a fan that helps distribute heat from a wood-burning stove to the rest of a house. Wood stoves give off radiant heat. Basically they are big hot boxes and tubes (the attached flues and chimneys) which glow heat into the surrounding space. This works fine for anyone sitting nearby, but the radiant heat may fail to reach others who are further away from the stove or in a different room. A stove fan is designed to tackle this problem by helping to evenly distribute the heat.


Some wood stove fans are electric but these have a couple of drawbacks. They add to the overall cost of running the stove and they can breakdown through constant exposure to high temperatures. A better solution is the self-powered fan which is powered purely and simply by the heat from the stove. This costs nothing and is more energy-efficient.


One way a self-powered stove fan can work is by way of a Stirling engine. Some of the heat from the stove is used to boil water. The steam from the boiling water drives a piston, which turns the blades of the fan. The spinning fan then propels excess heat above the stove into the living space.


Another type of self-powered stove fan relies on the so-called Peltier-Seebeck effect. The fan acts like a big heat sink, drawing heat from the stove up through an aluminum base. Partway up the base is a "peltier cooler." The difference in temperature between the bottom and top of the base causes the peltier cooler to generate low-voltage electricity, which powers the fan's motor. Ecofan manufacture a range of fans, such as the one shown here, that use this principle.