What kind of firewood do I need for my tiny wood stove?

Small wood stoves can burn a variety of fuels.  The best fuel for your personal stove will depend on your heating needs, availability of fuel in your local area, your ability to store bulk fuel, and your budget.

Bulk Cordwood

One of the most cost-effective options for fueling a small wood stove is to buy cordwood in bulk.  If you have space to store the wood, you can purchase an entire season's worth of fuel for relatively little cost.

Locally sourced bulk cordwood is one of the more sustainable options for fueling a small wood stove.  Landscaping companies and tree services often operate a side business re-selling waste wood from downed trees as firewood.

Bulk cordwood is typically sold wet or not fully cured.  Burning wet wood in your stove can cause excessive creosote formation and drastically reduce your stove's BTU output.  So, you'll want to be sure to cure your firewood before using it.

Naturally cured firewood can contain wood boring insects, so bulk cordwood should be used as close to the source as possible.  In general, avoid moving naturally cured firewood more than 10 miles.

A standard cordwood log is about 16" long, so chopping them in half makes a good size log for any size Dwarf stove.  If your dealer is willing to cut logs to order, we recommend 6-8" logs for the Dwarf 3kW, 8-10" for the Dwarf 4kW, and 10-12" logs for the Dwarf kW.

Curing Firewood

To cure firewood, split it and stack it loosely in a sunny location, perpendicular to the prevailing wind.  Cover the top of the stack only to keep precipitation off of it. The sides need to be exposed to allow airflow.

Different types of wood require different curing times, but in general, firewood needs to cure for a minimum of six months before it’s used.  Ideally, most firewood should be seasoned for 18 to 24 months.  Most firewood purchased in bulk has not been seasoned sufficiently for immediate use, so you’ll need to purchase it at least a year in advance.

Even if the wood dealer says that the wood has been drying for a year, you should examine it before using it.  Wood does not dry quickly until it is split and stacked.  A tree that has been down for over a year might still be more than half water.  Look for cracking on the cut ends of logs and bark that is falling off as good indications that firewood is properly seasoned. Properly cured firewood will weigh less than wet wood, and will make a sound like bowling pins when knocked together.  Wet wood will be heavy for its size and make a dull thud when knocked together.

The best way to tell if wood is properly cured is to use an electronic wood moisture meter.  Split a log and take a measurement from the center of the newly cut surface, parallel to the grain.  Properly cured wood should read less than 20% moisture content. If the wood reads higher than 20%, it needs a few more months to cure.

Kiln Dried Firewood

Hardware stores and grocery stores often sell packs of kiln dried firewood for around 6 per 0.75 cubic foot.  It is more expensive than cordwood, but can be a great option for fueling your small wood stove.

Kiln dried wood has been heat-dried, so it's already fully cured and ready to use in your stove.  And since the heat curing process kills any insects that may have been living in the wood, it's safe to transport kiln dried hardwood across long distances.  If you're purchasing kiln dried firewood for travel, look for the USDA certification on the label.

Pressed Logs

Commercially manufactured pressed sawdust logs, a.k.a. "Presto" logs or "fire logs," can be a great source of fuel for your small stove.  Manufactured logs tend to have relatively high BTU content, require no curing, and are safe to transport across long distances.

There are three general types of pressed logs available on the market.

Wax Logs

Logs that use wax as a binder are NOT safe to use in a wood stove.  The most common example of a wax log is Duraflame brand.

The limited air supply used in a wood stove can cause wax to fail to burn completely, and then condense inside the chimney as highly flammable creosote.  Because of the risk of chimney fire, wax logs are generally labeled to specifically prohibit their use in wood stoves.

Loose Pressed Sawdust Bricks

Sawdust bricks with a relatively loose consistency (and no wax binder) can be a good fuel source for small stoves.  Examples include the RedStone brand Ecobricks available at Tractor Supply.

Loose pressed sawdust bricks are made entirely of dry reclaimed hardwood sawdust, so they have very low moisture content and relatively high BTUs.

Since loose pressed sawdust bricks tend to shed sawdust relatively easily, they can be a bit messy to store and cut.  The logs burn very cleanly, but due to the loose consistency, they have relatively short burn times compared to heat pressed logs.

Heat Pressed Sawdust Logs

By far, our favorite pressed logs are the denser heat-pressed logs.  Made from reclaimed hardwood sawdust, these logs are formed with heat and very high pressure to make a super-dense, high-BTU, and long-burning fuel.

The availability of heat pressed logs seems to be regional, with most options available on the West Coast or the Pacific Northwest.  Our favorite heat pressed logs include:

• North Idaho Energy Logs
• Homefire Prest Logs
• Pres-to-Logs
• Bio Blocks

Foraged Wood

Downed wood that you found in the forest is not usually the ideal fuel for immediate use in your wood stove, but it can be used if necessary.  If no other fuel source is available, having the ability to heat your home and cook your food with found wood can be a literal lifesaver.

Tools for foraging include a small hand axe for chopping limbs and splitting logs, a sturdy firewood carry bag for carrying your fuel, a wood moisture meter, and a saw capable of cutting through a medium sized log.  An electric or gas chainsaw is very helpful, but a 21” or larger bow saw will work if you don’t mind the manual labor, and a human-powered saw may be most reliable in an emergency.

Learn to identify your local trees by their leaves and bark so that you can pick out desirable firewood.  Hardwoods like oak and maple are ideal for wood stove fuel. Softwoods have lower BTU content than hardwoods since they’re less dense, but they can also work well as stove fuel. Soft, sappy woods like pine should be avoided if possible, since they can cause excessive creosote formation.

Wood that has been down for a long period of time can still have a surprisingly high moisture content.  Look for downed wood that has been sitting for a long while, but isn’t rotten. Bark that is falling off is often a good sign that a piece of wood is worth investigating.  Sometimes a good piece of wood is rotten on the outside, but has a core of solid dry wood. Once you think you’ve found a good candidate, cut a log from it, and split the log.  Use a moisture meter on the freshly split surface to verify that the moisture content is 20% or lower. If the wood is dry, cut as many logs as you can carry back home.

Avoid using wet fuel if possible, but if you have no other choice, there are a few things you can do to improve your results.  Cut your driest fuel into kindling to get your fire going. Wet kindling will require several tries to start a fire. Cut your wet fuel into small pieces to make it easier to drive off the moisture, and put new logs in the fire before you need them, so they have time to dry out.  Understand that the heat output of your stove will be significantly reduced with wet fuel, and your chimney will fill with creosote much more quickly. Be sure to inspect your flue system frequently and sweep it as often as necessary to avoid significant creosote buildup.

Coal

In some parts of the United States, especially in Appalachia, coal is abundant and cheap.  Anthracite coal is best, since it is much cleaner, though bituminous coal could also be used if necessary.

The Dwarf 3kW Standard, Dwarf 4kW, and Dwarf 5kW are all capable of burning coal when connected to a well-designed flue system.  If using another model of small stove, check the manual to ensure that it is designed to burn coal.

If you are sourcing anthracite coal for a small stove, the "nut coal" size is generally best.  "Pea coal" will usually fall through the fire grate, and "stove coal" will leave large air spaces in the coal bed.

Coal burns very differently in the stove than wood.  Wood fires burn from the top, and benefit from lots of secondary air for an efficient burn.  Coal fires burn from the middle, so you should keep the primary air open when burning coal.  A coal bed needs to be sufficiently deep to sustain a fire, so you'll generally want to pile the coal up in the firebox as high as possible.  Modifications like a taller coal bar can help to make burning coal easier in a tiny stove.

Other Fuels

Most wood stoves can be used to burn a variety of solid fuels aside from wood or coal.  Charcoal is generally acceptable to use in a small stove, though it can be one of the more expensive options available.  Hardwood pellets or other solid fuels like corn or soybeans can be burned in a wood stove by adding a fireproof basket insert that fits inside the fire box.  We've even successfully used dried elk dung to fuel a Tiny Wood Stove, though it smells a bit like burning hair.

Unacceptable fuels for a wood stove stove include any liquid fuels, which could cause the stove or the flue to explode.  Do not burn plywood, OSB, or other wood products containing glue, since the burning glue can be toxic, and can cause hard to remove deposits inside the flue.  Pressed logs containing paraffin wax should also be avoided, since they can produce large amounts of flammable creosote. 

Don’t burn trash, leaves or pine needles. Newsprint can be used as tinder for starting fires, but don’t burn large quantities of paper in the stove, since paper creates large amounts of fly ash that can clog up your flue system.