I didn't get from the first post that the cable actually will run through an area where air that's part of the heating and cooling will flow. "Chasing along" does not say to me "chasing inside."

Plenum cable is designed not to outgas poisonous gases under heat, so they aren't needed if, say, they are in an attic going next to an A/C duct, but not sharing its air.

Be sure to check your locale with tvfool.com to see if any digital stations use VHF before deciding on the antenna.