Ductwork question

[CeloNC]

The PO of my 71 Sovereign tore out the ductwork that used to run from the rear closet to the vent under the tub. Not sure why this was done. I am thinking about fabricating an adapter onto the open end of the duct which will allow me to run round,flexible duct to the vent under the tub. I was also thinking about putting a split in the duct so I could run some back further into the rear access door area with the hopes of keeping the pipes from freezing. My AS is currently being used year round. Anybody out there dealt with this issue or have any ideas? Thanks, as always to the Airforum community.-Bill

[dznf0g]

You may find everything you need here:

DW Inc.

You can do pretty much anything you want....but be sure you have at least as much square inches of outlet at the furnace as the install manual calls for. In other words put in no more register shutoffs than will make it possible to restrict minimum flow.

Study your furnace and see if there are extra "blank" hookup locations available. You might not want to rob the one duct run for the pipe heater. It may make the outlet for that run not have enough volume and create a cold spot in the trailer.

[CeloNC]

Thanks for that info and the link to DW. I have installed a new NT30 SP and modified the old plenum to use the existing rectangular duct work (8" X 2 1/2" metal). There are three registers on my system, including the one in the bathroom that I need to run new duct to. It sounds like I might be asking for trouble if I divide the run to that last, bathroom register. Looking at the drawing for the original ductwork, I noticed that it contained a section that jogged and was about 16" X 16" right before reaching the last register. Any ideas why this would be, other than to make a gradual (less than 90 deg.) turn? Thanks.
Bill