Basics of Corn Stoves
Corn stoves are specifically designed to burn a granular fuel. Because this fuel is metered into the burning chamber, most stoves have a storage hopper to contain a supply of fuel. In some ways, corn burning stoves are very similar to pellet burning stoves. In both cases, corn and pellets are very dense. Consequently, neither of these fuels will burn readily in an open pile in a fire chamber.

To get these fuels to burn, some manufacturers use a small combustion chamber into which the corn is fed and combustion air is pumped through. The corn can be either dribbled into the combustion chamber from above, or it can be stoked into the chamber from below by means of an auger. The feed rate of this auger can be adjusted to regulate the amount of corn burned, which in turn controls the amount of heat produced. The second requirement form burning to occur is oxygen. In order to support combustion, oxygen is blown into the combustion chamber by means of a small fan. The combustion air is usually brought in from outside, not room air. This combustion chamber is actually quite small and could easily fit into a child’s lunch box.

Inside the stove, a heat exchanger is used to remove heat from the flue gasses and heat the room air. A fan is used to move the room air through the stove where it is warmed. This fan may also help in moving the heat further away from the stove.

A different style of corn stove also exists which does not use augers to feed in the corn or fans to provide combustion air or move heated air to the room. By careful design, these stoves will burn corn at the bottom of a hopper and radiate heat to the surrounding room. Unlike the previous type where electricity is used to stoke the fire and move the heat to the room, these stoves are not affected by electrical power outages.

The type of flue pipe required to vent the exhaust gasses from the stove will depend on the design of the stove or corn burning appliance. These flue pipes can range from those commonly used in wood stoves to through-the-wall vent pipes which actually pre-heat the combustion air by removing heat from the flue gasses. Follow the manufacturer’s recommendations regarding the type of flue pipe required. It is best to keep the flue pipe as short and straight as possible (keep the number of elbows to a minimum) to maximize the stove’s performance.

Types of Stoves
A number of different manufacturers are presently making corn burning stoves. They are available in a variety of sizes and styles. Here are some of the configurations available:

The size of fuel hoppers also varies greatly. This hopper size can range from holding one day to ten days supply of fuel.

One thing to consider with the freestanding stove or space heaters is the surface temperature of exposed metal parts. This is especially important if there are small children in the house.

Costs of Heating with Corn
Before you can accurately compare heating with corn to other heating fuels you have to look at a number of factors. Not only is price of the fuel important, but also the heating efficiency of the heating system and the energy content of a unit of each fuel.

Here is a formula which you can use to calculate your cost per million BTU’s of useable energy. This formula takes into account all these factors:

Cost per million BTU’s of useable energy =

(cost per unit of fuel x 1,000,000) divided by (energy content per unit of fuel(BTU) x seasonal heating efficiency)

Where: Cost per unit of fuel is in Dollars Energy Content Unit of Fuel in BTU’s Seasonal Heating Efficiency is in decimal form ie (70%=0.7)

Example: Lets look at an example where you are using corn at $2.50 per bushel in a stove which has a seasonal heating efficiency of 60%. What is the cost per million BTU’s of useable energy?

Corn Cost = $2.50 per bushel

Energy Content per bushel = 7000 BTU/lb x 56/lb/bu. = 392,000 BTU

Seasonal Heating Efficiency = 60% = .6

Dollars per million BTU’s Useable Energy =

(Cost per unit of fuel ($) x 1,000,000) divided by (Energy content per unit of fuel (BTU) x Seasonal Heating Efficiency)

=($2.50 x 1,000,000) divided by (392,000 x .6)

= $10.63

Therefore to supply one million BTU’s of heat to the house costs $10.63 when this stove operates at 60% efficiency, burning corn at $2.50 per bushel. The average older home requires approximately 100 million BTU’s of useable energy per year. When you do the calculations for your situation, keep in mind that the price charged per bushel of corn may vary from the market price when small quantities are purchased. Check the prices carefully before doing these calculations.

Limitations of Burning Corn for Heat
Possibly the first and most important limitation of corn as a fuel is the stove itself. If the stove uses augers to feed the corn into the combustion chamber and fans to maintain combustion and move heated air to the room then an electrical power interruption will shut the stove down. Very simply with this style of stove, no electrical power means no heat from your corn stove. Some stoves require a manual reset after a power interruption, as a safety feature.

Stove Buying Criteria
When purchasing a corn stove there are some questions which you should answer: