Should I insist on a new line set for this ductless mini split replacement? How should I do the lineset cover given that the current setup can't be easily opened?
The ductless mini AC at our Cabin needs replacing (missing half its old R22 coolant, likely leaking). I am getting bids on a new 18,000 BTU system, but I am having trouble getting contractors to work with the lineset cover. It runs like so (~20 foot run).
The lineset cover isn't the usual, purpose-built stuff. It appears to be simple aluminum flashing, the same shade as the siding. It's 3"x3" That's good because it hasn't faded (like lineset cover at our house). IMO, it looks pretty good (better than the rain-guttery lineset cover that's typical), but it cannot be taken apart.
I've pried and poked enough to figure out it seems to be made from this flanged U channel, attached underneath the J-channel that holds the siding next to it. (This specimen was found in the garage rafters.)
That means it can't just be popped open like regular lineset covers, and removing it would, I think, mean tearing up the siding all the way up, not a reasonable option. It's not over the siding, it's flush with the wall under the siding. The siding ends at the channel edge. The flanges from this appear to be nailed down under the J channel, which is then of course nailed down and holding the horizontal siding pieces.
The first AC replacement bid came in with the caveat from the contractor that his team would cut off the old lineset cover and do nothing if they couldn't get it back on properly. That's a recipe for a mess, so I'm not using them.
The next bidder wanted to simply re-use the old lines after flushing them. That sounds reasonable-ish, except that the insulation on these is likely completely rotted away under there. (The stuff at the bottom was falling apart) and I don't trust the 20 year-old copper lines. Moreover, the unit needs to be raised up between 4 inches and 1 foot (depending which heat pump we choose to use) and it's going to be rotated 90 degrees to be parallel to the wall, fan blowing out. I don't think the current line set can be made to do that.
As I see it, I have these options:
- Reuse old lines and leave lineset cover alone
- Run lines next to existing raceway and put them in new lineset cover.
- Take apart existing lineset cover, new lines in there, and patch up in some way.
The latter might work because I found in the rafters in the garage two 8-foot pieces of non-flanged U channel in the same shade. I think if I cut the face off the existing channel, I could then fit this U over it, seal it up with caulk, and be good to go. (The length of the sides of the U aren't equal, but I suppose some tedious trimming with the aircraft snips could fix that.)