Freshly cut green wood contains up to 50% moisture. That means that 50% of the weight of the wood is water. It also causes a lot of creosote buildup in your outdoor wood stove, as well as a lot of smoke. Seasoned firewood burns cleaner and more efficiently than unseasoned firewood.
When you try to burn green wood, you must first use up your precious BTUs from your fire to boil off the water in green wood. Those are BTUs that could have gone into your home but instead are wasted.
Properly seasoned wood contains only 20% moisture.
So the 3 Most Important Steps are as follows:
Obviously, splitting your wood opens it up to allow it to dry much faster. A round log will never properly dry - it will start to rot before it has had enough time to dry. Anything over 6 inches in diameter gets split.
Stacking wood allows it to air-dry faster, particularly if you only stack the wood in narrow piles so the air can flow freely. Many people stack their wood on pallets to keep the bottom layer from rotting.
Cover your woodpile on the top from rain. Do not allow your cover to hang far over the edges of the pile as this prevents airflow.
Wood that has been split to 6-inch diameter and has sat stacked and covered for at least six months is the most efficient fuel for your furnace.
The amount of time for proper seasoning depends upon many factors, but if you have a GASIFIER outdoor furnace, you should have already cut, split and stacked your wood for this upcoming winter. It will take at least 6 months for green hardwood to properly dry in order to burn properly in your GX Series or other gasification outdoor boiler. You actually should prepare your wood this summer for next Winter.
All other traditional outdoor wood boilers will sometimes operate a little better with some higher moisture content wood. This is because they are not high-efficiency outdoor wood burning boilers and a load of really dry wood will burn up like a pile of match sticks, and too much of that heat will exit the chimney before it has a chance to transfer through your furnace walls into your water jacket. Do NOT burn all green wood, but also don't just burn 'matchstick dry' firewood in your outdoor boiler either.
So for these traditional outdoor wood burners, it is ok to use wood that is less seasoned. We have some customers who mix some green wood in with their dry wood and they report that this works very well.
While we may disagree on the EPA's blundering policy, they created this somewhat useful video on the topic. It is less than 2 minutes in length and worth watching. (Ignore the comments about the health risks of wood smoke - as if there are ANY types of smoke that are actually good for your health!)
And if I were you, I would NEVER put a wood pile that close to a building!
But the EPA did get one thing right - Split, Stack, and Cover!