How to Install Duct Systems ?
Attach the Takeoff to the Main Supply Line
Mark the center point for the takeoff and drill a pilot hole using the cutting bit in the hole cutter. Preset the cutting tool to the correct diameter. Place the center guide in the pilot hole and start the cutting bit along the circumference of the hole. Use a right-angle drill because you have to work in a tight space, but you can attach the cutting bit to any drill. The cutting bit then swivels around the center guide
(Image 1), forming a perfect circle.
Note:Sheet metal hole cutters and right-angle drills are available at most rental centers or specialty stores.
After the takeoff is in place, reach in and bend the tabs over (Image 2) to secure it to the duct.
Install the Ceiling Register Boot
Install the ceiling register boot (Image 1) so you will know how long to cut the supply duct. Center it between the joist and screw into place with self-tapping screws.
Note:
Use a power nut driver to drive self-tapping sheet metal screws.
Measure the length you need for the supply duct. Take the measurement from about 1" inside the takeoff to about 1" into the boot collar.
Cut the duct to length with a round duct cutter. You need to use a round duct cutter because the cutter actually removes a thin strip of metal along the cut line (Image 2), which makes the cut a lot smoother. It is almost impossible to cut the metal with any other tool.
the duct together. It has a special snap lock built in at the factory.
Install the Damper
Install the damper into the duct by drilling a hole into the side of the duct and then screw the damper into place. The damper control indicator will show you whether the damper is open or closed.
Put the crimped end in first, then put the other end of the duct in. The takeoff rotates to make it easier to fit the duct into place.
Secure both ends with a few 1/2" sheet metal screws through the collar.
Install the Cold Air Return
For the system to work, you have to re-circulate the air back to the furnace. That is why you need a cold air return (Image 1).
Note:
If you had no return air in your room, you would create a positive pressure. That would then reduce the flow of conditioned air to that space.
Nail a piece of sheet metal onto the back of a stud cavity.
two holes -- one in the stud cavity and the other one into the existing return (Image 2).
Secure start collars (Image 3) into both holes.
non-insulated, flexible ducting to connect the two returns (Image 4).
plastic cable ties to secure the ducting.
