Low emission wood burning stove

Abstract

A wood burning stove is configured to produce low emissions and provide high efficiency. The stove includes a housing, a firebox disposed in the housing, a first air flow channel, a secondary air flow channel, and a lower primary air conduit. The secondary air flow channel includes a plurality of secondary air apertures configured to supply secondary air to a combustible gas emitted by a fire. The lower primary air conduit includes a plurality of conduit apertures configured to supply a second primary air flow into the firebox. Also disclosed are methods of operating such a stove.

1 . A lower primary air conduit for use in a wood burning stove, the lower primary air conduit comprising:
 a base portion and a neck portion disposed above the base portion;   an intake disposed in a bottom of the base portion; and   a plurality of conduit apertures disposed in a rear face of the neck portion, with the base portion extending rearward of the rear face of the neck portion;   wherein the plurality of conduit apertures are configured to direct a flow of primary air into a firebox of the wood burning stove.   
     
     
         2 . The lower primary air conduit according to  claim 1 , wherein the plurality of conduit apertures are oriented in different directions. 
     
     
         3 . The lower primary air conduit according to  claim 1 , wherein the plurality of conduit apertures comprises a middle conduit aperture that is oriented to direct the flow of primary air rearwardly. 
     
     
         4 . The lower primary air conduit according to  claim 1 , wherein the plurality of conduit apertures comprises at least one side conduit aperture that is oriented at a 45° angle away from the middle conduit aperture. 
     
     
         5 . The lower primary air conduit according to  claim 1 , wherein the lower primary air conduit includes three conduit apertures. 
     
     
         6 . The lower primary air conduit according to  claim 1 , wherein the neck portion includes a planar front face opposite the rear face. 
     
     
         7 . A wood burning stove comprising:
 a housing;   a firebox enclosed by the housing;   a primary air flow channel configured to provide a first flow of primary air into the firebox;   a secondary air flow channel configured to provide secondary air into the firebox; and   a lower primary air conduit configured to provide a second flow of primary air into the firebox;   wherein a portion of the secondary air flow channel is disposed above the primary air flow channel and the lower primary air conduit is disposed below the primary air flow channel.   
     
     
         8 . The wood burning stove according to  claim 7 , further comprising at least one secondary air tube disposed in the secondary air flow channel. 
     
     
         9 . The wood burning stove according to  claim 8 , wherein each of the at least one secondary air tube has a plurality of secondary air apertures. 
     
     
         10 . The wood burning stove according to  claim 7 , where the lower primary air conduit has a plurality of conduit apertures. 
     
     
         11 . The wood burning stove according to  claim 10 , wherein the conduit apertures are oriented in different directions. 
     
     
         12 . The wood burning stove according to  claim 7 , wherein the stove has a weighted particulate emissions rate less than 1.0 grams per hour. 
     
     
         13 . The wood burning stove according to  claim 7 , wherein the lower primary air conduit comprises:
 a base portion and a neck portion disposed above the base portion;   an intake disposed in a bottom of the base portion; and   a plurality of conduit apertures disposed in a rear face of the neck portion;   wherein the plurality of conduit apertures are configured to direct the second flow of primary air rearwardly into the firebox.   
     
     
         14 . A method for providing heat from a wood burning stove, the method comprising the steps:
 providing fuel in a firebox of the wood burning stove;   igniting the fuel in the firebox;   providing a first primary air flow into the firebox from a first air flow channel;   providing a secondary air flow into the firebox from at least one secondary air tube;   providing a second primary air flow into the firebox from a lower primary air conduit;   providing a flow of air into a shroud of the stove; and   moving heated air out of side vents of the shroud.   
     
     
         15 . The method for providing heat from a wood burning stove according to  claim 14 , further including the step of moving a primary damper to one of a closed position, a partially open position, and an open position. 
     
     
         16 . The method for providing heat from a wood burning stove according to  claim 14 , wherein the second primary air flow into the firebox is provided from a plurality of conduit apertures in the lower primary air conduit. 
     
     
         17 . The method for providing heat from a wood burning stove according to  claim 16 , wherein the plurality of conduit apertures in the lower primary air conduit are oriented in different directions. 
     
     
         18 . The method for providing heat from a wood burning stove according to  claim 14 , wherein the wood burning stove comprises three secondary air tubes with a plurality of apertures. 
     
     
         19 . The method for providing heat from a wood burning stove according to  claim 14 , wherein a weighted particulate emissions rate from the wood burning stove is less than 1.0 gram per hour. 
     
     
         20 . The method for providing heat form a wood burning stove according to  claim 14 , wherein the flow of air into the shroud is provided from a blower.