Furnace filter box and method of assembly

1. A furnace filter box adapted for mounting next to an intake air opening in a furnace, the filter box disposed under an air intake opening in a lower portion of a furnace, the filter box adapted for receiving at least one furnace filter therein for filtering intake air received from an air intake duct, the filter box comprising:

a vertical front panel with a furnace filter door, the front panel attached to vertical sides of a first side panel and a second side panel, the first and second panels attached to a vertical back panel, a horizontal bottom panel is attached to a bottom portion of the front, the back and first and second side panels;

a pair of horizontal furnace filter rails mounted to an inside of an upper portion of the first and second side panels, the filter rails adapted for holding the furnace filter next to an enlarged open top in the filter box and covering the open top; and

a vertical air intake opening in the first side panel, the air intake opening adapted for receiving an end of the air intake duct.

2. The filter box as described in claim 1 wherein the air filter rails are “U” shaped, air filter rails having a width of 1 inch and greater for receiving different widths of furnace filters.

3. The filter box as described in claim 1 wherein the furnace filter door is hinged to a top of the front panel, the furnace filter door disposed next to an end of the furnace filter rails.

4. The filter box as described in claim 1 further including a top panel attached to a portion of a top of the first and second side panels, the top panel disposed next to an enlarged open top in the filter box.

5. The filter box as described in claim 1 further including a plurality of S-lock channels used for attaching the bottom panel to a bottom of the front, the back and the first and second side panels.

6. The filter box as described in claim 1 wherein the upper portion of the first and second side panels include right angle flanges, the right angle flanges received in “U” shaped flanges on the furnace filter rails, when the filter rails are mounted thereon.

7. The filter box as described in claim 1 wherein the front, the back and the first and second side panels include spaced apart, vertical strength ribs formed therein for adding strength to the filter box.

8. The filter box as described in claim 1 wherein sides of the front and the back panels include right angle flanges, the right angle flanges received in “U” shaped flanges in the sides of the first and second side panels for securing the front and the back panels to the first and second side panels.

9. The filter box as described in claim 1 wherein the upper portion of the front and the back panels include right angle flanges in the top thereof.

10. A furnace filter box adapted for mounting next to an intake air opening in a furnace, the filter box disposed under an air intake in a lower portion of a furnace, the filter box adapted for receiving at least one furnace filter therein for filtering intake air received from an air intake duct, the filter box comprising:

a vertical front panel with a furnace filter door, the front panel attached to sides of a vertical first side panel and a vertical second side panel, the first and second panels attached to a vertical back panel, a horizontal bottom panel is attached to a bottom portion of the front, the back and first and second side panels, the front, the back and the first and second side panels includes spaced apart vertical strength ribs formed therein for adding strength to the filter box;

a pair of “U” shaped horizontal furnace filter rails mounted to an inside of an upper portion of the first and second side panels, the filter rails having a width of 1 inch and greater for receiving different widths of furnace filters, the filter rails adapted for holding the furnace filter next to an enlarged open top in the filter box and covering the open top; and

a vertical air intake opening in the first side panel, the air intake opening adapted for receiving an end of the air intake duct.

11. The filter box as described in claim 10 wherein the furnace filter door is hinged to a top of the front panel, the furnace filter door disposed next to an end of the furnace filter rails, whereby when the filter door is opened, the furnace filter can be inserted inside the filter box or removed from inside the filter box.

12. The filter box as described in claim 10 further including a top panel attached to a portion of a top of the first and second side panels, the top panel disposed next to the enlarged open top in the filter box, the top panel having a downwardly extending right angle flange disposed next to a top of the furnace filter door.

13. The filter box as described in claim 10 further including a plurality of S-lock channels mounted on right angle flanges disposed around sides of the bottom panel, the S-lock channels used for attaching the bottom panel to a bottom of the front, the back and the first and second side panels.

14. The filter box as described in claim 10 wherein the upper portion of the first and second side panels include right angle flanges, the right angle flanges received in “U” shaped flanges on the furnace filter rails, when the filter rails are mounted thereon.

15. The filter box as described in claim 10 wherein sides of the front and the back panels include right angle flanges, the right angle flanges received in “U” shaped flanges in the sides of the first and second side panels for securing the front and the back panels to the first and second side panels.

16. The filter box as described in claim 10 wherein the upper portion of the front and the back panels include right angle flanges in the top thereof.

17. A method of assembling a furnace filter box, the filter box adapted for mounting next to an intake air opening in a furnace, the filter box adapted for receiving at least one furnace filter therein for filtering intake air received from an air intake duct, the steps including:

attaching sides of a front panel with a furnace filter door to sides of a first side panel and a second side panel;

attaching the sides of the first and second panels to sides of a back panel;

attaching sides of a bottom panel to a bottom portion of the front, the back and first and second side panels,

mounting a pair of “U” shaped furnace filter rails to an inside of an upper portion of the first and second side panels, the filter rails having a width of 1 inch and greater for receiving different widths of furnace filters, the filter rails adapted for holding the furnace filter next to an enlarged open top in the filter box and covering the open top;

cutting an air intake opening in the first side panel, the air intake opening adapted for receiving an end of the air intake duct; and

mounting the assembled furnace filter box next to the intake air opening in the furnace.

18. The method as described in claim 17 further including a step of attaching a top panel to a portion of a top of the first and second side panels, the top panel disposed next to an enlarged open top in the filter box.

19. The method as described in claim 17 further including a step of forming spaced apart, vertical strength ribs in the front, the back and the first and second side panels prior to attaching the sides of the front panel to the sides of the first and second side panels.

20. The method as described in claim 17 further including a step of attaching S-lock channels to right angle flanges on sides of the bottom panel and attaching the S-lock channels to a bottom of the front, back and first and second side panels.