MINI SPLIT SYSTEM INSTALL

Following this with interest.

I have a new Pioneer ultra high efficiency mini split still in the boxes it came in. I have not had the uninterrupted time to complete the install. With a second new truck coming, I'll have to at least get the first one done at some point this fall.

The friend that got me on this has this model on a 780 Volvo for 2 years now if I recall. He's running his straight off an inverter, no generator. He claims to make it through a 10 hour break and still start the truck, using some sketchy old wet cell batteries. One improvement he is planning last we talked about it was having a custom tarp/cover made to fit the outside unit to protect against salt spray in the winter when it's not in use.

I'm hauling a reefer, so I got my jump start right there if it comes down to it. I'm planning to try it that way at first. If I have start problems, I'd be inclined to install a couple more batteries and a load switch rv style versus a diesel apu. I fought that battle some years with a really old TriPac and done with those.

One thing different, I chose to make my own outside rack out of 304 stainless. That part I got done, just need to drill some holes in it when it's time to mount. So this post is not entirely without content LOL. First picture is a mock-up, imagine the ground is the back of the cab. The feet on the bottom of the legs will bolt underneath with the leg socket just peeking out enough to clear, the upper piece straight to the back of the cab. Second picture is the upper corner detail showing how the legs fit. It's 1" thick wall sliding into 1-1/4" thick wall. There will be a bolt through it to secure it. I decided not to weld in place to make it easier to remove if I decide to do that at some point.

 

Man, that looks GOOD, stainless welding can be a real pita

 

I know this is old but would you happen to have a link for that mount? Also have you had issues with that mount?

 

I'm not the OP, but it's an Amazon screenshot. I didn't see that exact one, but there's many like it (link).

Not that anyone asked, I considered something like that when mounting mine, but opted to make one instead. I've seen them out there and never seen signs they fell off or broke, but didn't ask either. I'm just not comfortable with the look of those universal mounts.

The problem I see is that it's intended for the exterior wall of a house. That is, not bouncing down the road and only attaches to the rear face of the cab with a limited range of position to either hit a structural piece or place some sort of reinforcement behind the skin for strength. Still leaves a good bit of weight hanging out there just suspended by the wall too. I was thinking one trip through Indiana would probably do it in. Those chinesium brackets aren't very robust.

I made mine with 304 stainless, and it's cut to exactly fit the structural pieces under the skin. 1-1/2 angle 1/8 thick for the frame, then the legs are 1" thickwall square tube. Both ends fit and bolt into 1-1/4 thickwall stubs, one welded to the frame up top, the bottom is welded to a piece of 1/4 flat that is attached to the frame rail under the cab. The attachments at the top/back of the cab go through a frame structure and also have a short piece of 1/8 mild steel steel 2" angle as a backer. Probably over-built, and definitely a bit more expensive. Probably $300 worth of materials, bandsaw blades, drill bits, welding rod, etc plus about a half a day to cut up all the steel and put it together.

I've seen similar homemade racks like mine out in the wild, but usually bolted together hardware store angle that's maybe painted, and doesn't look as finished IMO. One or two I've seen use outside support legs attached up higher vs under the cab like mine. One like that I recall was hauling a reefer with a fairly short wheelbase Freightliner with the 5th wheel up pretty snug to the cab, and did it for a low mount that would clear underneath the reefer unit in a turn. Speaking of clearance, I did have to cut a few inches off the top of my pogo stick so it would clear that right hand leg when turning right. A few things to look out for.

Really a 100 ways to do it if you put your mind to it. Measure once cut twice and all that.

 

Yeah I've seen both out here and about the only thing i.worry about with custom mount is what if I go with a different unit and the mounting holes go from 20 inches to 23 then I gotta remake everything.
Did you do your own rivetnuts into the wall or pay a shop to install em?

I ordered mine with rubber hoses instead of copper to help with a less fail point as ordered rubber mounting supports. Thought about just removing my toolbox from my catwalk and putting it there but I really like my toolbox lol

This is the unit I went with. I like to sleep in the cold so felt 12k was great
Pioneer® 12,000 BTU 20.8 SEER2 Ductless Mini-Split Inverter+ Air Conditioner Heat Pump System Full Set 115V

 

My frame attaches with thru bolts not rivnuts. I positioned them over structural pieces behind the surface, and also used some short pieces of 2x2 1/8 angle on the back to spread the load better. I cut some 1/8 rubber to make a gasket/soft mount between the frame and the cab.

I been thru fitting a different compressor and it's not a big deal as you'd think. Long story short, I ordered the 22 SEER model on the second (my) truck and built the rack to the same dimensions as the first one. I discovered upon setting the unit that they had shipped me the 20 SEER unit, which is a bit smaller. The low effort solution was to bolt in a couple pieces of flat steel to attach the feet since they fell inside the frame. In hindsight, I'd say having to make and mount an entirely new frame would be unlikely.

Here's some detail pics from when I was building the frame. I know that installed pic may be a little unclear about how the thing is put together and goes on. Truth be told, nearly all of the custom fitting is primarily how it attaches to the truck. That is, attaching to strong enough mounts in the right spots. Making little modifications to fit a different unit after the fact, is less effort than meets the eye.

This is assembled, imagine the ground as the back of the cab for perspective. The "feet" at the lower end fit under the cab, secured with bolts going straight upward into the structural beam they lay against. Since they extend about 4 inches under the cab, I set the frame up on 4x4's to make sure I had the angles right on the legs.


This is the mount that attaches to the rear face of the cab. Mounted, there's two holes drilled with bolts going through. If this were mounted already, the perspective is looking up directly under where the compressor unit sits.

 

Nice mount unfortunately I don't own a welder or know how to weld lol
Where did you buy some 304 at? I was honestly thinking of buying some angle iron and iron square tubing from lowes and using my fairing mounts as they are thick and very sturdy( I stand on them quite a bit when working on starlink system lol.
Was gonna remove the metal bar move my airline holder over and use those holes as extra support and put bolts there and thru the existing holes already on the fairings. Did you leave much space on the back side that's facing the cab? Was gonna only leave couple inches.
Mounting it up higher as I may go back to flatbed work as I really miss it.
Right now I pull reefer
I've thought about just putting thru bolts thru and getting like a 2mm thick plate for the inside wall to spread the weight between all 4-5 holes but not sure I really wanna drill more holes in the back wall

 

The mounting feet for the Pioneers are pretty much spot welded on, so they can break due to vibrations and stress from the roads. I use a pair of 1" ratchet straps to reinforce it and reduce any movement that will weaken the welds. The straps should only be tightened so that there is no play when you push or pull on the unit. If you over tighten the straps, they can bend the fins or cause the fan to rub against the shroud.