1. Locate the center line for the bottom duct opening on the furnace cabinet (Item 3). This may be done by measuring from the extreme back of the furance cabinet a distance of 20-15/8" on a line parallel to the length of the cabinet.
2. Cut an opening in the floor 10-9/16" x 3-13/16" as shown in the diagram.
3. Secure the bottom duct adapter (Item 1) to floor using wood screws or nails.
4. Place bottom duct gasket (Item 2) over adapter as shown.
5. Remove knock-out from bottom of furnace (Item 3) adn center the opening over the bottom duct adapter.
6. Secure furnace cabinet to floor.
7. Seal any leaks around duct adapter with duct tape.