Hi, I'm Dave Osborne. With over 50 years experience as a journeyman carpenter, foreman and contractor in heavy construction I enjoyed working with apprentices and sharing the tricks of the trade that others shared with me. Now I get emails from Members all over the world and we include many of my answers in our Free Monthly Newsletters. Some of my answers include drawings and instructions specific to a project, but may also answer your questions. I use correct construction terminology, so you can confidently inform your building supply dealers or contractors exactly what you need.
Membership gives you full access to our hundreds of how-to articles, woodworking plans, converters, calculators and tables. Our Stair Calculator is one of the most popular on the internet. We have projects you can build for (and with) your kids, furniture for your wife, and sheds and gazebos. If you run into a problem or need advice your Membership includes unlimited email questions to me through our Ask Dave quick response button.
I am refinishing the basement and need two additional air ducts in the bedroom and bathroom from the existing central air conditioning plenum. I need suggestions and/or diagrams on the proper assembly. I want to use rigid ducting and am looking at possibly 4" or 6" diameter with the total length of both locations of 8 linear feet.
Use a 5" or 6" diameter duct. You need to buy an adapter from the 5" duct (for instance) that will fit a standard 4x10 or 3x12 floor register. The adapter or boot is secured to framing in the wall or a square hole cut in the floor. The other end which goes into the plenum is fitted through a proper sized hole in the plenum, notched about 1" x 1" to form tabs. Each alternate tab is bent into the inside of the plenum and its alternate is bent onto the outside. Space out 3 screws around the duct on the outside and screw these tabs into the plenum. Wrap proper foil adhesive tape (not duct tape) around the outside of the 5" duct and the plenum to seal off any air leaks. Also tape the joints with this tape as well.
Dave(Ask Dave) (About Dave)
As an introduction get free access to this article
and two others of your choice, just by entering
your email address below.
Receive our FREE Monthly newsletter which contains a
free set of woodworking plans each and every month.