Wood Stoves - Firewood
EPA Exempt Wood Stoves
The term exempt, as used by the EPA, means the stoves do not meet the criteria
necessary for EPA wood stove certification. For this reason, EPA exempt stoves are not
for sale in the States of California and Washington and may be prohibited by individual
EPA exempt stoves remain a popular choice because just about anybody can afford
one. A list of EPA exempt stoves by make and model can be found here.
EPA Certified Wood Stoves - Catalytic and Non Catalytic
EPA certified wood stoves are classified as catalytic or non catalytic. Using different
technologies, catalytic and non catalytic stoves burn not only the wood, but the gases
produced during combustion. The burning of these gases is called secondary
combustion and results in higher efficiency and lower emissions in compliance with EPA
Catalytic Wood Stoves
A catalytic wood stove employs a catalytic combustor to produce secondary
combustion. This honeycomb shaped, palladium coated device resides above the
firebox and burns the wood gases as they pass through it on their way to the flue.
A catalytic combustor will degrade over time, but should last 5-6 years if maintained
according to the manufacturer's instructions. Replacement cost is around $200.
Non Catalytic Wood Stoves
A non catalytic stove achieves secondary combustion without a catalytic combustor.
Instead, it relies on firebox insulation, a large baffle on the roof of the firebox to
produce a longer, hotter gas flow path, and preheated combustion air introduced
through small holes above the fuel in the firebox. This method of secondary combustion
is also called an "advanced combustion system."
Here's a list of EPA Certified stoves. (PDF)
Wood Stove Sizing
One measure of a stove's size is its heat output measured in BTUs. Various wood
stoves have ratings of 35,000 to over 100,000 BTUs. The BTU rating of the wood stove
you buy should be sized to the number of square feet you're heating.
A rule of thumb for figuring this out is 35 BTUs for every square foot of heated space.
For example: A 1,200 sq. ft. ranch would require a stove rated around 42,000 BTUs.
(35 x 1,200 = 42,000)
If your home has more than one story, plan on heating only the floor where the stove
is located. Although heat rises, it doesn't rise fast enough to comfortably heat upstairs
bedrooms and the bath. Consider supplementing the heat in these rooms with small
Wood Stove Venting and Installation
The venting and installation procedure for a wood stove is unique to the home where
it's installed. Before having your stove installed, check with your local Building
Department regarding building codes and permits, and notify your fire insurance
Proper venting is critical to reducing pollution and maintaining high efficiency and a safe
environment. Consult a certified installer about the need for a flue liner in your
masonry chimney. This liner can help maintain proper draft and prevent icing, which can
block your chimney.
Use the manufacturer's recommended flue diameter. An improperly sized flue won't
provide the draft needed to operate the stove.
If you live near a source of
cheap, or free firewood,
there's no more cost effective
or popular heating appliance
than the wood burning stove.
Despite the recent sales
boom in wood pellet and corn
stoves, over 70% of the
appliances found in homes
are wood stoves.
Basically, the wood stoves
manufactured today are
classified as either EPA
Certified or EPA Exempt.