Page 12 - Advanced Technology for Energy and Water Saving

¬ WOOD AND BIOMASS

T HERE’S SOME CONTROVERSY over whether biomass is a “renewable” form of energy

production. Sure, wood, bamboo and other forms of biomass “grow back” from the
soil. But when burned, they rapidly release their CO content, as opposed to the
2
gradual release of rotting into the ground.
In our view, biomass is an excellent transitional form of heat energy. In other
words, it’s a good “stopgap” to warm our homes for a few years while we switch to a cleaner
heating method, such as solar PV and heat
pumps (see right).
Biomass burners, both commercial and
residential (in the form of wood stoves) have
improved dramatically. They burn much
cleaner than their predecessors, but they still
have an air pollution problem. Compared
with other forms of “renewable” energy, even
the best biomass burners produce a large
amount of particulate, some of it especially
harmful to human lungs. That’s why, in our
view, unless technology improves to make
them burn even more cleanly, they should
be treated as supplemental heating systems
on the way to other, less polluting systems.

Fresh Air Intake—

A Wood-Burning Imperative

Too often, wood-burning boilers and stoves in homes are installed without a
dedicated fresh air source. Stoves without a source of fresh air can badly pollute
your home’s air with dangerous flue gases—leading to asthma or other illnesses.
Here are several solutions.
Combustion air is often overlooked when installing boilers and furnaces in homes,
yet it’s a key safety and health feature.
One low-tech solution is a wood stove thimble, which allows fresh air to come in
at the point where the wood stove or pellet stove pipe exits the wall. This system
has the added benefit of preheating the incoming fresh air to some degree, and
requires no additional piping.
Another simple, cost-efficient way to bring in some air to fuel the combustion
in your wood stove is to install a pressure-sensitive passive vent in a wall nearby Outdoor access. Without a fresh air
inside attached to a four-inch duct. Tamarack makes a vent of this sort that’s very source, wood burners can cause other
affordable. A lot of modern wood stoves have a fresh air intake flange already combustion appliances to backdraft.
installed, just waiting for an air supply.

12ADVANCED TECHNOLOGY FOR ENERGY AND WATER CONSERVATION