Every once in a while a discussion comes along about firebox volume advertised for stoves. With various comments about manufacturers misrepresenting the volume in their stoves. Well folks, the fact is the manufacturer does not set the rules. The EPA does and EPA Method 28, the rule book for cert. testing wood stoves, tells ya exactly how to measure it the same way the test labs do.
Here in all of their glory and simplicity are the measurement rules. Run right down to the stove store and go to measuring the stoves. Well, until the store owner calls the cops. :lol:
3.4 Firebox means the chamber in the wood heater in
which the test fuel charge is placed and combusted.
3.5 Height means the vertical distance extending
above the loading door, if fuel could reasonably occupy that
space, but not more than 2 inches above the top (peak
height) of the loading door, to the floor of the firebox
(i.e., below a permanent grate) if the grate allows a 1-inch
diameter piece of wood to pass through the grate, or, if
not, to the top of the grate. Firebox height is not
necessarily uniform but must account for variations caused
by internal baffles, air channels, or other permanent
obstructions.
3.6 Length means the longest horizontal fire chamber
dimension that is parallel to a wall of the chamber.
3.16 Width means the shortest horizontal fire chamber
dimension that is parallel to a wall of the chamber.
8.7.1 Determine the firebox volume using the
definitions for height, width, and length in Section 3.
Volume adjustments due to presence of firebrick and other
permanent fixtures may be necessary. Adjust width and
length dimensions to extend to the metal wall of the wood
heater above the firebrick or permanent obstruction if the
firebrick or obstruction extending the length of the side(s)
or back wall extends less than one-third of the usable
firebox height. Use the width or length dimensions inside
the firebrick if the firebrick extends more than one-third
of the usable firebox height. If a log retainer or grate is
a permanent fixture and the manufacturer recommends that no
fuel be placed outside the retainer, the area outside of the
retainer is excluded from the firebox volume calculations.
8.7.2 In general, exclude the area above the ash lip
if that area is less than 10 percent of the usable firebox
volume. Otherwise, take into account consumer loading
practices. For instance, if fuel is to be loaded
front-to-back, an ash lip may be considered usable firebox
volume.
8.7.3 Include areas adjacent to and above a baffle
(up to two inches above the fuel loading opening) if four
inches or more horizontal space exist between the edge of
the baffle and a vertical obstruction (e.g., sidewalls or
air channels).
Here in all of their glory and simplicity are the measurement rules. Run right down to the stove store and go to measuring the stoves. Well, until the store owner calls the cops. :lol:
3.4 Firebox means the chamber in the wood heater in
which the test fuel charge is placed and combusted.
3.5 Height means the vertical distance extending
above the loading door, if fuel could reasonably occupy that
space, but not more than 2 inches above the top (peak
height) of the loading door, to the floor of the firebox
(i.e., below a permanent grate) if the grate allows a 1-inch
diameter piece of wood to pass through the grate, or, if
not, to the top of the grate. Firebox height is not
necessarily uniform but must account for variations caused
by internal baffles, air channels, or other permanent
obstructions.
3.6 Length means the longest horizontal fire chamber
dimension that is parallel to a wall of the chamber.
3.16 Width means the shortest horizontal fire chamber
dimension that is parallel to a wall of the chamber.
8.7.1 Determine the firebox volume using the
definitions for height, width, and length in Section 3.
Volume adjustments due to presence of firebrick and other
permanent fixtures may be necessary. Adjust width and
length dimensions to extend to the metal wall of the wood
heater above the firebrick or permanent obstruction if the
firebrick or obstruction extending the length of the side(s)
or back wall extends less than one-third of the usable
firebox height. Use the width or length dimensions inside
the firebrick if the firebrick extends more than one-third
of the usable firebox height. If a log retainer or grate is
a permanent fixture and the manufacturer recommends that no
fuel be placed outside the retainer, the area outside of the
retainer is excluded from the firebox volume calculations.
8.7.2 In general, exclude the area above the ash lip
if that area is less than 10 percent of the usable firebox
volume. Otherwise, take into account consumer loading
practices. For instance, if fuel is to be loaded
front-to-back, an ash lip may be considered usable firebox
volume.
8.7.3 Include areas adjacent to and above a baffle
(up to two inches above the fuel loading opening) if four
inches or more horizontal space exist between the edge of
the baffle and a vertical obstruction (e.g., sidewalls or
air channels).
