Traditional wood stoves and fireplaces waste firewood, pollute the air and are unsafe and unhealthy. People with asthma or heart problems are at special risk. Be especially aware to stoves manufactured before 1990 and to conventional fireplaces.
Traditional fireplaces may lose more than 90% of the heat they produce through the chimney and emit dangerous pollutants: CO, CO2, dangerous toxins, including dioxin, arsenic and formaldehyde.
New units may overcome most of these problems. Qualified wood and pellet stoves, or new fireplace inserts, are a much better choice; many have sealed combustion, their emissions are a small fraction of those of older units, and since they draw the combustion air from the outside and exhaust combustion products, they do not pose the health hazards of older units.
Anyway, there are still questions hanging over: is wood burning - using the new wood and pellet stoves and fireplace inserts - an energy-efficient or an environmentally-friendly choice?
Wood-burning can be in some sense carbon-neutral, but there are other issues that we should be aware of.
Yes to Wood burning
Wood is a renewable energy source, and as long as it is grown and harvested sustainably, it's a good fuel. Burning wood releases CO2, but the trees can sequester more CO2 than the one released during the combustion of the timber; in this sense heating with wood is a carbon-neutral choice.
You just have to use high-performance equipment: high-tech wood and pellet stoves and inserts, certified by the EPA or other agencies.
This is especially true for rural regions where clean-burning timber is available. In this view, wood is a better choice than gas or other fossil fuels.
No to Wood Burning
Unfortunately there is also an environmentally-unfriendly side that we should not forget. Wood can generate more air pollution than any other fuel, and it may not be grown and harvested sustainably.
New fireplaces and stoves, even the best ones, still release significant amounts of pollutants, that are not sequestered or burned.
In the North America, most stove manufacturers claim to meet the 75% efficiency threshold (to make their stoves eligible for the Federal $300 tax credit), but many of their stoves do not meet that value. They deliberately forget the habits of wood-burning users, especially the use on improperly seasoned wood; and that affects greatly the emissions and the efficiency of wood stoves.
Wood-Burning and highly insulated homes
Wood is, in most cases, a very poor choice in energy-efficient homes.
Energy efficient homes have very high levels of insulation and air-tightness, crucial to avoid heat losses, and to enable the house to have small heating systems. And this strategy – the best for high energy savings and the most environmentally-friendly – requires a heating system with a versatile heat output, which is difficult or impossible to achieve with wood or pellet stoves...