I want to install recessed lighting in my kithcen. There is an A/C register in my ceiling. Is there any easy way to determine where the ductwork run is so I can avoid it. Mine is a 2-story house so no access is available.
Remove the grille and reach up into the register box. You should be able to feel which way the duct is exiting from the register box. Unless your entire ceiling if furred down, the dust will be running in a bay between two floor joists, provided you are framed with dimension lumber. Consider this entire joist bay off limits for recessed cans, unless you can determine that the duct only runs horizontally a short distance before turning up. If you are framed with open web trusses, the duct could could change directions multiple times, especially with flex duct.