We have an exterior HVAC line running up the center of an exterior wall to a second floor unit. The face in question is the side of a colonial style, and has a two story chimney with a taper at the top of the first story. Currently the line is only protected by an ugly galvanized steel cover. These are the only two features on this face of the house, with the chimney about one third of the way from the rear of the house, and the HVAC line approximately dead center. There is no eave overhang on the side, and the line only runs to the top of the second floor, not all the way to the roof.
We are re-siding the house with Hardie Board (cement board), a slightly expensive job. The contractor recommends (and I agree) that putting the HVAC line back inside the walls is a bad idea, since any HVAC repairs would require tearing off siding (brand new, and expensive), or putting on an exterior cover (ugly).
The current plan is to frame out an exterior chase (there is no interior chase from crawlspace to attic), and run the lines in there. While it's the best plan I've heard of yet, I'm not a fan of some random column of siding running up the outside off the house. We discussed running the chase along the chimney, but the jog at the top of the first floor will make that weird, plus require HVAC line relocation.
Are there any ways to "hide" the exterior HVAC line, or to camouflage the exterior chase so that it doesn't look likely an out-of-place mistake that will lower appeal? I'm open to literally any ideas, but can say that we've already ruled out building an internal chase (too complicated/expensive). For reference, this is a nice-ish house built in the 70's/80's, in a decent part of town - there are no historical or aesthetic restrictions, just an upper-middle-class house that were trying to take good care of.