I have space in the ceiling cavity area directly above my HVAC system (furnace & AC) in my basement to run new PEX/plumbing lines, and I would like to run my PEX lines that need to cross from one side of my basement to the other side in this open area that is directly above the HVAC system. Will locating them there be prevented by building code (perhaps because a leak would run down into the HVAC system)? If building code restricts this, what are the general distance restrictions related to plumbing lines above or near HVAC systems? Thank you.