High efficiency water heater

• US 20040011301A1
• Filed: 02/26/2003
• Published: 01/22/2004
• Est. Priority Date: 06/04/2002
• Status: Active Grant

• Current Assignee: Bradford White Corporation
• Original Assignee: Bradford White Corporation
• Inventors: Campbell, Ross, Gordon, Michael, Sutherland, Jason, Stafford, Christopher, Scott, Timothy D.
• Granted Patent: US 7,559,293 B2
• Time in Patent Office: Days
• US Class Current: 122/155.1
• CPC Class Codes: F24H 1/205 with furnace tubes
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]

Abstract

A flue system is provided for a water heater having improved heat exchange efficiency. The flue system includes an upstream heat exchange portion having at least one substantially vertical flue tube. The flue system also includes a downstream heat exchange portion having at least one substantially vertical flue tube. The upstream heat exchange portion provides a first pass for heat exchange with water in a water heater. The downstream heat exchange portion provides a second pass for heat exchange with water in the water heater.

Claims

1. A flue system for a water heater having improved heat exchange efficiency, said flue system comprising:

an upstream heat exchange portion having at least one substantially vertical flue tube; and

a downstream heat exchange portion having at least one substantially vertical flue tube,

said upstream heat exchange portion providing a first pass for heat exchange with water in a water heater and said downstream heat exchange portion providing a second pass for heat exchange with water in the water heater.

2. The flue system of claim 1 further comprising an upstream collector positioned to direct combustion products from said upstream heat exchange portion toward said downstream heat exchange portion.

3. The flue system of claim 1 wherein said upstream heat exchange portion provides primary heat exchange with water in the water heater, said downstream heat exchange portion provides secondary heat exchange with water in the water heater, and said upstream heat exchange portion is configured to transfer more heat to water in the water heater than said downstream heat exchange portion.

4. The flue system of claim 1 wherein said downstream heat exchange portion includes at least two substantially vertical flue tubes.

5. The flue system of claim 1 wherein said downstream heat exchange portion provides at least two passes for heat exchange with water in the water heater.

6. The flue system of claim 5 further comprising a downstream collector positioned to direct combustion products from one of said passes of said downstream heat exchange portion toward another of said passes of said downstream heat exchange portion.

7. A water heater having improved heat exchange efficiency, said water heater comprising:

a water tank; and

a flue system positioned to extend at least partially through an interior of said water tank and to transfer heat from combustion products within said flue system to water in said water tank, said flue system including an upstream heat exchange portion having at least one substantially vertical flue tube and a downstream heat exchange portion having at least one substantially vertical flue tube, said upstream heat exchange portion of said flue system providing a first pass for heat exchange with water in said water tank and said downstream heat exchange portion providing a second pass for heat exchange with water in said water tank.

8. The water heater of claim 7, said flue system of said water heater further comprising an upstream collector positioned to direct combustion products from said upstream heat exchange portion of said flue system toward said downstream heat exchange portion of said flue system.

9. The water heater of claim 7 wherein said upstream heat exchange portion of said flue system provides primary heat exchange with water in said water tank, said downstream heat exchange portion of said flue system provides secondary heat exchange with water in said water tank, and said upstream heat exchange portion is configured to transfer more heat to water in said water tank than said downstream heat exchange portion.

10. The water heater of claim 7 wherein said downstream heat exchange portion of said flue system includes at least two substantially vertical flue tubes.

11. The water heater of claim 7 wherein said downstream heat exchange portion of said flue system provides at least two passes through said water tank for heat exchange with water in said water tank.

12. The water heater of claim 11 further comprising a downstream collector positioned to direct combustion products from one of said passes of said downstream heat exchange portion toward another of said passes of said downstream heat exchange portion.

13. A water heater having improved heat exchange efficiency, said water heater comprising:

a blower configured to receive fuel and air, said blower being oriented to deliver the fuel and air along a substantially vertical axis;

a burner positioned downstream from said blower along said axis to receive the fuel and air, said burner being configured to deliver the products of combustion of the fuel and air along said axis; and

a flue tube having a segment extending along said axis, said flue tube being positioned to receive the products of combustion from said burner, and said flue segment providing a first pass for heat exchange with water in said water heater.

14. The water heater of claim 13 wherein each of said blower, said burner, and said segment of said flue tube is oriented along said vertical axis, said blower being positioned above said burner, and said burner being positioned above said segment of said flue tube, such that the products of combustion are directed downwardly through said segment of said flue tube.

15. The water heater of claim 13 further comprising a transition tube positioned to provide a flow path between said blower and said burner and to couple said blower to said burner.

16. The water heater of claim 13 further comprising a water tank through which said segment of said flue tube extends, said water heater further comprising a mounting flange for coupling said burner to said water heater, said mounting flange being positioned to traverse said segment of said flue tube and to orient said burner along said vertical axis.

17. The water heater of claim 13 further comprising an igniter positioned proximal to said burner to ignite the premix of fuel and air and a sensor positioned to detect of a flame at said burner, wherein said igniter and said sensor are positioned at opposite sides of said burner such that they are separated by about 180 degrees.

18. The water heater of claim 13 further comprising a venturi for receiving fuel and air, said blower receiving the fuel and air from said venturi.

19. A system for exhausting combustion products and draining condensate from a flue system of a water heater, said system comprising a receptacle positioned to collect combustion products and condensate from the flue system, said receptacle defining an orifice positioned to exhaust combustion products from within said receptacle, and said receptacle also defining an outlet positioned to drain condensate from said receptacle.

20. The system of claim 19 wherein the size of said exhaust orifice is selected to control heat output from the water heater.

21. The system of claim 19, said receptacle comprising a body portion and a receptacle component mounted to said body portion of said receptacle for defining said exhaust orifice and said condensate outlet.

22. The system of claim 21 wherein said exhaust orifice is provided by an aperture formed in said receptacle component.

23. The system of claim 21 wherein said condensate outlet is provided by a notch formed in said receptacle component.

24. The system of claim 21 wherein said exhaust orifice and said condensate outlet are distinct from one another.

25. The system of claim 21 wherein said body portion of said receptacle is a molded component.

26. The system of claim 19 wherein said receptacle is configured to be coupled to an exhaust conduit and to deliver exhaust to said exhaust conduit through said exhaust orifice.

27. The system of claim 19 wherein said receptacle is configured to be coupled to a condensate drain and to deliver condensate to said condensate drain through said condensate outlet.

28. A flue system for a water heater comprising:

an upstream heat exchange portion for providing a first pass for heat exchange with water in the water heater; and

a downstream heat exchange portion for providing a second pass for heat exchange with water in the water heater, said downstream heat exchange portion including at least one substantially vertical flue tube having an inner surface exposed to combustion products flowing through said vertical flue tube and an outer surface exposed to water in the water heater, each of said inner and outer surfaces being coated to reduce corrosion of said vertical flue tube.

29. The flue system of claim 28 wherein said inner and outer surfaces of said vertical flue tube are lined with a corrosion resistant coating.

30. The flue system of claim 29 wherein said coating includes glass.

31. An assembly for directing products of combustion between segments of a flue of a water heater, said assembly comprising:

an insulator at least partially defining a chamber configured to direct products of combustion between the flue segments; and

a cover configured to at least partially surround said insulator, said cover also being configured to be coupled to a water tank of the water heater;

said insulator in an uncompressed state being dimensioned to extend outwardly from said cover when said insulator is positioned in said cover, and said insulator in a compressed state being dimensioned to permit coupling of said cover to the water tank.

32. The assembly of claim 31 wherein said insulator comprises a first insulator and a second insulator in contact with one another.

33. The assembly of claim 31 wherein said cover comprises a receptacle having a wall portion, said wall portion being configured to be coupled to the water tank when said insulator is in said compressed state.

34. A water heater comprising:

a water tank;

flue segments extending through said water tank; and

a collector assembly for directing products of combustion between said flue segments, said collector assembly including an insulator at least partially defining a chamber configured to direct products of combustion between said flue segments, and a cover configured to at least partially surround said insulator and being configured to be coupled to the water tank, said insulator in an uncompressed state being dimensioned to extend outwardly from said cover when said insulator is positioned in said cover, and said insulator in a compressed state being dimensioned to permit contact between said cover and the water tank.

35. The assembly of claim 34 wherein said cover comprises a receptacle having a wall portion, said wall portion being configured to be coupled to the water tank when said insulator is in said compressed state.

36. A method of providing an insulated passage for products of combustion between flue segments of a water heater, said method comprising the steps of:

(a) positioning an insulator in a cover such that a portion of the insulator extends out of the cover;

(b) compressing the extended portion of the insulator against a water tank of the water heater such that the cover is proximal to or touching the water tank; and

(c) coupling the cover to the water tank, thereby forming a sealed and insulated passage between the flue segments.

37. The method of claim 36 wherein said coupling step comprises welding the cover to the water tank.

38. The method of claim 36 wherein said coupling step further comprises welding a wall portion of the cover to the water tank.