I have a 3yr old home that when the builder built my house they did not put registers in the walk in closets in my master bath or master bedroom. As you can tell they are freezing in the winter and boiling in the summer. I would like to add them myself. I had an HVAC guy out once and he explained to me what i needed to do to fix the problem myself, but that was about a year ago and don't really remember what he told me. thanks for the help