Finishing up Mini-Split install, sealing/insulation questions

[SJP0tato]

Hi guys,
this weekend I completed the major portions of install for a mini-split 12k BTU unit in my garage. Things are working great, but I have a few specific questions to finish things up:

I used sealing compound, similar to "Thum-Gum" like such: https://www.amazon.com/dp/B002SSGARY/?tag=atomicindus08-20
for sealing all the voids in the outer wall where conduit, the mini-split 2.5" sleeve, and screw holes are. I used enough to completely fill any gaps and seal against the stucco. Will this be adequate for long-term rain protection, or should i use something else instead/in addition?

One more thing I wasn't sure about: The 2.5" port for the lines/wire/drain in the wall is not sealed, with maybe 80% of its volume taken by the previous items. What's a good solution to insulate the remaining space? I wasn't sure if expanding foam is a good choice, since it would crush the soft plastic drain hose (which has been trimmed since that picture).

Lastly: The drain hose is the flimsy clear plastic tube pictured, is there something better I should source from the hardware store? I was thinking of PVC or at least a thicker tube. I have a feeling the Phoenix sun will completely destroy that hose within a year.

Thanks for any suggestions, other people's posts about mini-split installs have been very helpful for my install!

 

[justinjoyal]

Expanding foam to fill the voids, color matched caulking to seal around holes.

Cpvc works great for drains. Or reinforced plastic hose.

 

[Ohmthis]

I love foam for filling voids and sealing, BUT not in this instance. I like to pack fiberglass in the void and then foam just the outside portion. If you need to get to the lines for repair it can be a ***** to get the foam out. Just clean the outside layer and then pull the glass out.

 

[Moose364]

the light wall 3/4 PVC works perfect. the drain line coming form the Mini split fits nice and snug in it

 

[PoorOwner]

Just a couple squirt of spray foam did it for me. My garage was not insulated so figure the foam was better than the stucco at insulating. The outside foam is protected by a lineset cover which the top edged are caulked.

I was very aware on the foam may crush stuff. Home Depot has one made by Loctite which dries similar to a stylofoam and not overly aggressive. I didn't want a really soft foam that may get chewed up either. If you don't over do it, the foam expands outwards and won't crush anything, just run a hacksaw blade to trim it afterwards.

By the way I thought maybe your outside unit need a bit more space away from the wall for best ventilation like 12" minimum. What does the manufacturer manual say?

 

[tab2]

I think I will go with non/low expanding foam to seal the hole. It's not THAT bad to cut out if you have to.

Poor brings up a good point, I looked quickly and I think Pioneer's clearance is 12" from the rear.

https://www.highseer.com/pdf/WAS_WYS_IM2.pdf

Scroll to page 20

 

[SJP0tato]

Thanks guys, I'll pick up some of the low-expansion foam on the way home today!

As to the spacing: From what I've read it mostly has to do with snow accumulation behind the unit. If you use a wall hanging bracket, I think you can get as close as 3" with no problems (since snow wouldn't accumulate).

Since it's here in Phoenix the chance of snow is pretty low, and the unit will only be used intermittently when I'm working out in the garage. I'll just have to be sure no debris accumulates back there, but otherwise I think it should be okay.

 

[justinjoyal]

You need to have enough space behind the unit to be able to clean it.