Crown Royal Stoves RS7200E, Руководство пользователя, Страница: 34 / 53

Burning materials not recommended by the manufacturer can play a major role in visible
emissions. Materials such as plastics, garbage, rubber tires, and even wood products such as
cardboard and paper that may be coated with petroleum products may emit excessive smoke.
Fire starters such as gasoline, oil, and other chemicals can also make an ordinary wood fuel load
seem very dirty once burned. If people who own outdoor furnaces start fires with some kindling
and load with wood fuel as recommended above, they can eliminate a lot of the smoke that
others see and the problems that go with it.
5. Loading
The amount of wood loaded into an outdoor furnace in relation to the firebox size also
has an effect on visible emissions. For every size of wood load there is a minimum amount of
space needed to complete the combustion process. For instance, if a person were to load a
relatively small firebox completely and load a larger firebox with the same amount of wood, with
all of the other factors being the same, the larger firebox would burn cleaner. In the smaller
firebox, the combustion process does not have enough room to expand, heat up, and mix before
exiting the firebox (insufficient time, temperature, and turbulence). Just because a firebox is
large does not mean that it should be filled completely. This large volume is used in part for
what happens AFTER it is loaded.
B. Furnace Size
The size of a furnace should be large enough to provide sufficient heat without constant
reloading. If the target burn time is 12 hours, an adequately sized furnace will provide enough
heat for 90% of all heating days. There will always be the extraordinarily cold days for which no
one can plan. A small furnace that needs constant reloading will unavoidably be left unattended
and will lose much of its available heat. In these situations, the firebox is left relatively cold and
restarting will be dirtier because of flame quenching on the cool firebox walls. A good rule to
follow is be that if the furnace cannot stay within 20% of its set point under regular reloading,
then it is undersized and a larger furnace is needed.
C. Chimney Considerations
Although chimney height has little to do with overall emissions, it should be considered
in ALL installations of outdoor furnaces. Installers and dealers should first take a look at the
proposed location and take a few things into account. Location of nearby buildings, structures,
and natural geography all affect the furnace’s ability to draft. While higher is generally better, it
is sometimes tough to convince the furnace owner to add length to the chimney because of the
extra cost.
VI. Conclusions
The proper use of an outdoor furnace can significantly reduce the visible emissions that it
produces. Simple fuel considerations with regard to moisture content, size, and amount help
hinder the production of smoke and ultimately help improve efficiency. Other obvious ways to
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