Tesla: Why would there be any noise? Conduit does not vibrate. There should be no vibration from the air handler/furnace either.
Not being a wise guy, but what do you base your comment on?
Reno: Yes, I also was 'taught' not to touch. I think Tiger has his furnace conduit strapped to the riser duct, which is common practice. I still don't see an NEC violation.
