There have been several posts that I've seen that ask how to tell if what they are seeing is smoke or steam... er... condensation. The other morning, we had a nice cold start to the day - about 5ºF. I got the fire going good and hot and went outside to capture the steam as it shot out of the stack and condensed a few feet above the top and turned white. If your chimney looks like this on very cold days, don't be alarmed. It's only the water vapor that the wood creates as a product of combustion.
Notice how the "smoke" doesn't materialize until a few feet from the chimney? That's because it comes out so hot that it's still in vapor form. As it gets away from the stack, it quickly chills and condenses into tiny fog-like droplets, like are found in clouds. Then, as it moves farther away, it evaporates into the dry winter air without a trace. Real smoke is brown or blue, and it lingers in the air for quite a while.
FWIW... Laboratories have burned wood in controlled situations and have determined that for every pound of dry wood burned, 0.54 pounds of water will be created in addition to the water that is already in it. The water comes from combining the hydrogen molecules in the wood with the oxygen molecules in the air. Two hydrogen atoms combine with one oxygen atom to make one molecule of H2O - water. There are an awful lot of hydrogen molecules in wood, so burning it in air makes an awful lot of water.
For example, a 10 pound split that measures 25% MC on your moisture meter has 8 pounds of wood fiber and 2 pounds of water. When you burn it to completion, that 2 pounds, plus 0.54 times 8 pounds of wood fiber (4.32 pounds) makes a grand total of 6.32 pounds of water that has to go up the chimney without condensing onto the flue walls. That's over three quarts of water produced for every 10 pounds of seasoned wood burned.
So... burn hot, my friends, and get that water up, out, and away from the chimney. ;-)
Notice how the "smoke" doesn't materialize until a few feet from the chimney? That's because it comes out so hot that it's still in vapor form. As it gets away from the stack, it quickly chills and condenses into tiny fog-like droplets, like are found in clouds. Then, as it moves farther away, it evaporates into the dry winter air without a trace. Real smoke is brown or blue, and it lingers in the air for quite a while.
FWIW... Laboratories have burned wood in controlled situations and have determined that for every pound of dry wood burned, 0.54 pounds of water will be created in addition to the water that is already in it. The water comes from combining the hydrogen molecules in the wood with the oxygen molecules in the air. Two hydrogen atoms combine with one oxygen atom to make one molecule of H2O - water. There are an awful lot of hydrogen molecules in wood, so burning it in air makes an awful lot of water.
For example, a 10 pound split that measures 25% MC on your moisture meter has 8 pounds of wood fiber and 2 pounds of water. When you burn it to completion, that 2 pounds, plus 0.54 times 8 pounds of wood fiber (4.32 pounds) makes a grand total of 6.32 pounds of water that has to go up the chimney without condensing onto the flue walls. That's over three quarts of water produced for every 10 pounds of seasoned wood burned.
So... burn hot, my friends, and get that water up, out, and away from the chimney. ;-)
