Air inlet damper

Abstract

A fuel fired, atmospheric water heater has a burner positioned inside a combustion chamber. All combustion air entering the combustion chamber must pass through a damper. The damper is operable to adjust the flow resistance to combustion air entering the combustion chamber. The damper is biased to a closed position such that during non-firing periods of the water heater, the damper significantly reduces the flow rate of combustion air being provided to the combustion chamber reducing standby heat loss. An actuator is in fluid communication with a fuel supply line such that when pressurized fuel is provided to the burner, the pressurized fuel causes the actuator to move the damper to an open position to permit operative combustion air delivery to the combustion chamber during firing periods of the water heater.

What is claimed is: 
     
         1 . A water heater comprising:
 a combustion chamber;   a burner disposed in the combustion chamber;   a fuel valve operable to adjust a flow rate of fuel between a first flow rate and a second flow rate greater than the first flow rate;   a fuel supply line communicating between the burner and the fuel valve for supply of pressurized fuel from the fuel valve to the burner;   an air inlet assembly mounted to the combustion chamber and operable to permit combustion air to enter the combustion chamber, the air inlet assembly including:
 a damper movable between a first position corresponding to a first resistance to air entering the combustion chamber and a second position corresponding to a second resistance to air entering the combustion chamber, wherein the first resistance is greater than the second resistance; 
 an actuator operable to move the damper between the first position and the second position; 
 a conduit communicating between the actuator and the fuel valve such that the actuator moves the damper to the first position in response to the first flow rate and the actuator moves the damper to the second position in response to the second flow rate. 
   
     
     
         2 . The water heater of  claim 1 , wherein the water heater is an atmospheric water heater. 
     
     
         3 . The water heater of  claim 1 , wherein the actuator has no electrical components. 
     
     
         4 . The water heater of  claim 1 , wherein the fuel valve is operable to infinitely adjust the fuel flow rate. 
     
     
         5 . The water heater of  claim 4 , wherein the damper resistance is infinitely adjustable as a function of the fuel flow rate. 
     
     
         6 . The water heater of  claim 1 , wherein the actuator includes a diaphragm and a pin, such that the pin is coupled to a first side of the diaphragm and a second side of the pin is in fluid communication with the conduit. 
     
     
         7 . The water heater of  claim 1 , further comprising an arm functionally connecting the actuator and the damper. 
     
     
         8 . The water heater of  claim 1 , further comprising a closure mechanism to bias the damper to the first position. 
     
     
         9 . The water heater of  claim 8 , wherein the closure mechanism is a counterweight positioned on the damper. 
     
     
         10 . The water heater of  claim 8 , wherein the closure mechanism is a spring. 
     
     
         11 . The water heater of  claim 8 , wherein the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position 
     
     
         12 . The water heater of  claim 1 , wherein the damper translates between the first position and the second position. 
     
     
         13 . The water heater of  claim 1 , wherein the damper rotates about an axis from the first position to the second position. 
     
     
         14 . The water heater of  claim 1 , wherein the damper includes a front portion and a rear portion; and when the damper is in the second position the front portion is lower than in the first position and the rear portion is higher than in the first position. 
     
     
         15 . The water heater of  claim 1 , wherein a flame arrestor is located between the combustion chamber and the air intake assembly such that substantially all the combustion air passing through the air intake assembly must pass through the flame arrestor before arriving in the combustion chamber. 
     
     
         16 . A control system for a flow of combustion air to a combustion system of a water heater, the control comprising:
 a fuel valve for supplying fuel to the combustion system at a selected flow rate; and   a damper restricting combustion airflow to a combustion chamber as a function of the fuel flow rate.   
     
     
         17 . A control system of  claim 16 , wherein the damper is movable between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance. 
     
     
         18 . A control system of  claim 16 , wherein an actuator operably moves the damper between a first position corresponding to a first resistance to combustion air entering the combustion chamber and a second position corresponding to a second resistance to combustion air entering the combustion chamber, wherein the first resistance is greater than the second resistance. 
     
     
         19 . A control system of  claim 16 , wherein the actuator has no electrical components. 
     
     
         20 . A control system of  claim 16 , wherein the combustion air being supplied to the combustion chamber is substantially at atmospheric pressure. 
     
     
         21 . A control system of  claim 17  wherein the damper translates from the first position to the second position. 
     
     
         22 . A control system of  claim 17 , wherein the damper rotates about an axis from the first position to the second position. 
     
     
         23 . A control system of  claim 17 , wherein a closure mechanism biases the damper to the first position. 
     
     
         24 . A control system of  claim 23 , wherein the closure mechanism is a spring. 
     
     
         25 . A control system of  claim 23 , wherein the closure mechanism is a counterweight. 
     
     
         26 . The water heater of  claim 23 , wherein the closure mechanism is achieved by designing the damper so that its own weight biases it to the closed position 
     
     
         27 . A method of controlling the flow of combustion air to a combustion system of a water heater, the method comprising:
 controlling a flow of fuel to the combustion system with a fuel valve; and   controlling a flow of combustion air to the combustion system with a damper by setting a flow resistance of the damper as a function of a flow rate of fuel from the fuel valve.   
     
     
         28 . The method of  claim 27 , further comprising communicating the fuel valve with the damper via a conduit; wherein controlling a flow of combustion air includes actuating the damper in response to pressure of fuel in the conduit. 
     
     
         29 . The method of  claim 27 , further comprising providing an actuator operable in response to pressure; exposing the actuator to pressure of fuel supplied by the fuel valve; and wherein controlling the flow of combustion air includes actuating the damper with the actuator in response to pressure of the supplied fuel. 
     
     
         30 . The method of  claim 29 , wherein actuating the damper with the actuator includes interconnecting the actuator with the damper by way of an actuator arm.