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.

  • 1
    You've done a good job of describing the scenario, but a photo is golden.
    – isherwood
    Sep 27, 2017 at 18:01
  • 1
    Painting the galvanized cover is really the only solution. Sep 27, 2017 at 21:27
  • 3
    HVAC lines inside the walls are better protected from the elements and possible damage. I have not had a line set leak or found a leak except at joints usually at the compressor. The line sets are usually soft copper and would be easy to hide in the wall.
    – Ed Beal
    Sep 28, 2017 at 1:47
  • 1
    Normally these lines are run through the walls without a joint and is fine. The only choices you will have that I know of is to frame a chase or paint it .. the chase might look as odd as the HVAC line.
    – Ken
    Sep 28, 2017 at 3:53

3 Answers 3


We ended up having the line rerouted to beside the chimney and will use a line-set cover to disguise the run and make it look similar to a downspout.

If I had to do it all over again, I would have had the line run over to the corner of the house, up the edge by the downspout, and into the attic near the edge of the soffit (finishing the line run in the interior). This would have better camouflaged the cover, as it does look incredibly similar to a downspout, but is rated to carry HVAC line.

Example product


There isn’t any reason not to run it inside the wall. Just pressure test the lines for a few days for leaks. If it holds it will hold for as long as you are alive providing you don’t put a nail through it. Alternatively you could frame out a soffit on the outside of the building and cover it with the same siding as the rest of the house, trim it and paint it.

  • The essential reason we were given not to do this involved the amount of repair work after running the line through the wall, not to mention likely cutting a double-thickness floor joist on the second floor (and thereby an unacceptable structural compromise). Plus there is no option to do a simple inspection or repair in the future, so any future change/repair would involve the same in-depth repairs to the drywall or siding. May 2, 2018 at 19:11

There are adjustable plastic covers that pop on and won't fall off and are profession grade; some are even paintable.

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.