Is pine good for outdoor wood burning furnace?

While pine can be used as firewood, it may not be the best choice for an outdoor wood burning furnace due to its relatively low heat output and potentially high sap content. Here are a few reasons why:

Low Heat Output: Pine has a lower heating value compared to other hardwoods like oak, hickory, or maple. This means that it burns hotter but produces less heat overall. As a result, you may need to use more pine to achieve the same heat output, increasing your fuel consumption.

High Sap Content: Pine is known for its high sap content, which can cause creosote buildup in your furnace and chimney. Creosote is a flammable substance that can lead to chimney fires and other safety hazards. Regular cleaning and maintenance may be necessary to prevent these issues when burning pine.

Quick Burning: Pine burns quickly, which can make it challenging to maintain a steady temperature in your furnace. You may find yourself needing to add more wood more frequently to keep your furnace running efficiently.

Sparks and Embers: Pine tends to produce more sparks and embers than other hardwoods. This can be a safety concern, especially if your furnace is located near flammable materials.

Ash Content: Pine produces more ash compared to some hardwoods. This means you'll need to clean the ash pan in your furnace more frequently.

If you have a limited supply of other hardwoods available or are looking for a cost-effective option, pine can be used in moderation. However, it's generally recommended to use hardwoods like oak, hickory, maple, or ash as the primary fuel for an outdoor wood burning furnace due to their higher heat output, lower sap content, and slower burn rate.