• Burning wood is a cost-effective way to heat a home.firewood image by Juliette Speers from Fotolia.com
  
  When providing heat to the home, a wood-burning furnace or boiler is a choice that many people make. Rural locations offer plenty of wood fuel at a cheap rate, burning wood indoors releases irritants, and messy ash- and wood-burning furnaces are more cost-efficient than other similar electronic devices. Whatever the reason, one important factor should be considered before a wood-burning boiler is installed: stainless steel versus carbon steel construction.
  
  

The Firebox

• The firebox of a boiler is the metal compartment that contains the burning wood and transfers heat to the boiler. This can be constructed out of regular carbon steel or out of high-grade stainless steel. The differences between the two come down to the function that you want in your outdoor wood boiler. Factors like heat transfer, corrosion resistance and malleability of the metal determine how a boiler will function and how easy it will be to repair or maintain.
  
  

Stainless Steel Pros

• Using a stainless-steel firebox has a number of positive effects for the functionality and design of a wood-burning boiler. Stainless steel is very highly corrosion resistant (hence "stainless") and will not rust or pit throughout many years of use. Also, stainless steel is lighter than heavy carbon steel and can be fabricated into lighter, smaller components that perform the same function.
  
  

Stainless Steel Cons

• Stainless steel is not very malleable (easy to bend or cut), so repairs or modifications are more difficult and expensive to perform. Also, stainless steel is more expensive than traditional carbon steel products and is actually slightly less efficient when it comes to heat transfer from the firebox. Another effect of using stainless steel is that during heating and cooling, the steel expands and contracts by up to 25 percent more than traditional steel, impacting the integrity of welds and seams.
  
  

Carbon Steel Pros

• Using traditional carbon steel in a wood-burning boiler has a few of its own benefits. For instance, carbon steel transfers heat at a higher rate than stainless steel, resulting in a quicker end temperature. Also, unlike stainless steel, carbon steel is generally easier to cut and work with, making repairs and modifications a bit easier. Carbon steel is also significantly cheaper to use than stainless when fashioning a firebox.
  
  

Carbon Steel Cons

• Traditional carbon steel is very prone to corrosion, especially when it is left outdoors and in contact with moisture or soil. The cleaning and treatment of carbon steel becomes tougher because of this and lends itself to carbon and soot buildup more so than stainless steel. Also, using a carbon-steel firebox will result in lime scale buildup in the boiler water on the other side of the heat exchange. This effect can nullify any efficiency bonus in heat transfer carbon steel may have over stainless.