|
 Forget
everything you may have thought about wood burning. Many of
us may have had experiences of open log fires in our
childhood or in other people's houses. They were dirty and
smelly. They are difficult to light and as soon as the wind
blew in the wrong direction to smoke would come into the
room and choke everyone. Most of the heat went up the
chimney and it just looked like an accident waiting to
happen. You'd be crazy to want that, right? Right.
However, in
Scandinavia they have been investing in Wood Burning
Technology for decades. Obviously they have a lot of trees
and some of the population is not connected to grid supplies
of electricity or gas. Hence there was a big market for
clean burning, modern, hi-tech, wood burning equipment. But
let us get one thing straight - the "open fire" is neither
practical nor healthy. You cannot control the rate of burn
and all the heat goes up the chimney.
What you need is
a wood burning stove. It will need one-third the wood of an
open fire and be about 70% efficient. Even better than that
- the Ceramic stoves (or "Kachelofens") are over 90%
efficient. They are lit once a day and the stove then stays
hot for a long time. A small home can benefit from a stove
with a back-boiler to heat water for radiators. Larger
houses can use a large water cylinder to store the heat from
a stove working once a day.
Many pellet
stoves and boilers are now self-igniting. They have a hopper
at the top which you fill every few days or weeks. Wood
pellet appliances can easily be 'turned down' because
(unlike log stoves) the fuel and air supply can be better
controlled. Efficiency can reach 90% and emissions are very
low. The key to a 'clean burn' is high temperature. A clean
burn means no harmful emissions. Wood pellet stoves use 0.5
to 1.5kg per hour
Clean-burning
wood should emit virtually no sulphur dioxide and very low
levels of nitrous oxides (which are typically found in
industrial smoke). It should also emit very low amounts of
smoke particulates. Many wood-fire appliances are now
certified for operation in 'smoke-free' zones. |
