AIR INTAKE COUPLING WITH NOISE SUPPRESSION FOR LOW NOx EMISSION FURNACE

Abstract

An air intake coupling has at least one noise suppression hole formed therein. A gas-air mixer elbow is fluidly coupled to the air intake coupling. A burner box assembly is fluidly coupled to the gas-air mixer elbow via a gas-air plenum box. A heat-exchange tube has a first end that is fluidly coupled to the burner box assembly. A fan is fluidly coupled to a second end of the heat-exchange tube via a cold-end header box.

1 . An air intake coupling comprising:
 a first tubular section;   a second tubular section fluidly coupled to the first tubular section;   a pressure tap formed in the first tubular section; and   at least one noise suppression hole formed in the second tubular section.   
     
     
         2 . The air intake coupling of  claim 1 , wherein the at least one noise suppression hole comprises a plurality of noise suppression holes. 
     
     
         3 . The air intake coupling of  claim 2 , wherein the plurality of noise suppression holes include a first noise suppression hole and a second noise suppression hole that are formed on opposite sides of the second tubular section. 
     
     
         4 . The air intake coupling of  claim 3 , wherein the first noise suppression hole is formed on opposite sides of the second tubular section approximately 180 degrees from the second noise suppression hole. 
     
     
         5 . The air intake coupling of  claim 4 , wherein the first noise suppression hole and the second noise suppression hole are formed via a single drilling operation. 
     
     
         6 . The air intake coupling of  claim 2 , comprising a pressure tap formed in the first tubular section, wherein the first noise suppression hole is in line with the pressure tap. 
     
     
         7 . The air intake coupling of  claim 2 , wherein at least one noise suppression hole of the plurality of noise suppression holes is round. 
     
     
         8 . The air intake coupling of  claim 1 , wherein the first tubular section and the second tubular section are integral. 
     
     
         9 . The air intake coupling of  claim 1 , comprising a flange formed on an end of the first tubular section on a side opposite the second tubular section for facilitating assembly of the air intake coupling to a fresh-air intake 
     
     
         10 . An air intake coupling comprising:
 a first tubular section;   a second tubular section fluidly coupled to the first tubular section;   a pressure tap formed in the first tubular section;   at least one noise suppression hole formed in the second tubular section; and   a flange formed on an end of the first tubular section on a side opposite the second tubular section for facilitating assembly of the air intake coupling to a fresh-air intake.   
     
     
         11 . The air intake coupling of  claim 10 , wherein the at least one noise suppression hole comprises a plurality of noise suppression holes. 
     
     
         12 . The air intake coupling of  claim 11 , wherein the plurality of noise suppression holes include a first noise suppression hole and a second noise suppression hole that are formed on opposite sides of the second tubular section. 
     
     
         13 . The air intake coupling of  claim 12 , wherein the first noise suppression hole is formed on opposite sides of the second tubular section approximately 180 degrees from the second noise suppression hole. 
     
     
         14 . The air intake coupling of  claim 12 , wherein the first noise suppression hole and the second noise suppression hole are formed via a single drilling operation. 
     
     
         15 . The air intake coupling of  claim 12 , comprising a pressure tap formed in the first tubular section, wherein the first noise suppression hole is in line with the pressure tap. 
     
     
         16 . The air intake coupling of  claim 15 , comprising:
 a mounting hole formed in the flange; and   wherein the mounting hole is in line with the pressure tap and the first noise suppression hole.   
     
     
         17 . The air intake coupling of  claim 11 , wherein at least one noise suppression hole of the plurality of noise suppression holes is round. 
     
     
         18 . The air intake coupling of  claim 10 , wherein the first tubular section and the second tubular section are integral. 
     
     
         19 . An air intake coupling comprising:
 a first tubular section;   a second tubular section fluidly coupled to the first tubular section;   a pressure tap formed in the first tubular section;   at least one noise suppression hole formed in the second tubular section; and   a pressure tap formed in the first tubular section, wherein the at least one noise suppression hole is in line with the pressure tap.   
     
     
         20 . The air intake coupling of  claim 19 , wherein:
 the at least one noise suppression hole comprises a plurality of noise suppression holes; and   the plurality of noise suppression holes include a first noise suppression hole and a second noise suppression hole that are formed on opposite sides of the second tubular section.