Colorado Department of Public Health and Environment Urges Careful Consideration Regarding the Purchase and Installation of Outdoor Wood-fired Boilers
September 26, 2007—Denver—The Colorado Department
of Public Health and Environment is reminding residents that
outdoor wood-fired boilers, which are gaining popularity as
an alternative residential energy source, are subject to
state air quality regulations and should be purchased and
installed conscientiously. Outdoor wood-fired boilers, or
OWBs, are wood-fired water heaters that are located outdoors
and are separated from the home or building being heated. At
first glance, they look like outdoor sheds with smokestacks.
Fires in the OWBs’ large fire boxes heat water that is
circulated into the home through underground pipes. The
energy may be used to heat houses, shops, domestic hot
water, greenhouses, swimming pools and spas. Colorado
retailers have seen a surge recently in the purchase and
installation of OWBs as an alternative to more traditional
natural gas-fired furnaces and other devices as home heating
sources. Some residents are purchasing and installing OWBs
in preparation for the upcoming winter season. One reason
for the growing popularity of OWBs is the availability of
inexpensive and/or free wood to stoke the boilers - a result
of the Mountain Pine Beetle infestation in North-Central
Colorado and from other forest restoration and wildfire
mitigation activities occurring throughout the state. “We
understand the interest in these devices from an economic
perspective,” said Paul Tourangeau, director of the Colorado
Department of Public Health and Environment’s Air Pollution
Control Division. “The fuel can be cheap or even free, and
they provide an effective method for disposing of wood that
has resulted from wildfires, insect and disease events, and
related forest improvement projects.” Tourangeau, however,
cautioned residents regarding the thick smoke and air
pollutant emissions that can be generated by the OWBs.
“These devices are subject to air quality regulations that
govern opacity, or the thickness of smoke. If not well
engineered or properly maintained, they can create a lot of
smoke that can affect a neighborhood. It’s important that
Coloradans consider this when deciding whether or not to
purchase a wood-fired boiler, or which model they choose to
buy. Consumers have options. While there are a number of OWB
manufacturers, only a handful utilize cleaner-burning
technology. We encourage everyone to do a little homework
and make a choice that is wise for themselves, their
neighbors and their community.” Most OWBs employ primitive
combustion technology. When the water circulating through
the furnace reaches a certain temperature, the air supply to
the fire is cut-off, cooling the fire so the water will not
overheat. The furnace operates in this "idle" mode until the
water temperature hits a lower temperature and the air
supply is re-established. This results in poor combustion
and potentially heavy smoke. Most of the smoke emitted is
fine condensed organic material that does not burn under
cool, oxygen-starved conditions. The choice of wood also
can have an impact on how much smoke OWBs generate. For
example, green wood full of moisture causes poor combustion.
Wood from an outdoor winter woodpile also may be very cold
when loaded into OWBs, causing less efficient fires. Wood
from urban sources (demolition and/or construction debris)
should not be used as it may include paints, glues or other
contaminants that exacerbate the pollution potential. OWBs
are subject to provisions of Colorado Air Quality Control
Commission Regulation No. 1, which details emissions
controls for particulate matter, smoke, carbon monoxide, and
sulfur oxides. Regulation No. 1 sets a 20 percent opacity
standard for devices like OWBs. If found to be in violation
of the opacity standard, the owner or operator may be
subject to an enforcement action from the Air Pollution
Control Division that could result in a fine. The Colorado
Department of Public Health and Environment urges residents
to educate themselves regarding OWBs. A lot of information
is available on-line through sites like www.woodheat.org and
a variety of state-run sites. “We appreciate that many
individuals want to use biomass to replace fossil fuels,”
said Tourangeau. “However, this can be done without adding
to air pollution concerns. Cleaner technologies are
available, so consumers can make wise choices.” --30-- |
