Our current mini split is a 12k BTU single head unit. And while it works awesome nearly all the time, it does struggle to cool the whole trailer during the hottest months, and sometimes during those hot times, we switch over to working a night shift to avoid the burning sun( ironic, isn’t it. A couple people who make their living from the sun trying to avoid it. 😄😄🤷♂️) and sleep during the hottest parts of the day.
Which is great, except the best the mini split can do leaves the bedroom part of the trailer at 90 degrees or so, and after a long work day, that’s just kinda miserable.
It’s not entirely the mini splits fault-the issue is really one of air flow and where the current single head unit is, the airflow is just sorta excluded from the bedroom area due to the layout of the trailer.
So we decided to up size the mini split to a multi head unit and install a second head in the bedroom and leave the existing one in the main kitchen area.
Which should be simple, but of course isn’t.
First, the outside compressor unit is significantly larger than the previous unit.
I had taken a lot of careful measurements and concluded that the new compressor would be able to just barely fit in the mounting space that I had built for the old one, making the compressor swap tricky, but not terribly hard.
Well, that turned out to not be the case in the real world, and fitting the new compressor unit would eventually require a massive amount of work.
Oops.
Second, the multi zone mini split is a 240vac unit, and our old one was 120vac.
Which isn’t convenient because our trailer’s entire electrical system is only 120vac, so some creativity and special hardware is needed to overcome that issue.
Also, that means the existing head unit needs swapped out for a higher voltage unit, so more work there.
Anyway, what was supposed to be a not-too-terrible job has morphed into a full blown project.
Here’s the trailer pulled into the shop and about to go under the knife.
Again. 😄😄🙄
Here’s the front end of the trailer dissected and the new, larger compressor unit in the foreground.
It was supposed to be able to just barely fit in the cage where the old one was, which you can see still attached to the trailer with just the top cut off.
After the agony of an entire day of trying to figure out how this much larger compressor unit was going to fit on the tongue of the trailer, I finally came to the conclusion that the entire tongue area needed to be completely torn down and this compressor would require a complete new mounting system engineered, along with a new propane tank mounting system.
This meant that not only the old air conditioner brackets, but the load equalizer and anti sway mounts that I had all so carefully and THOROUGHLY welded to the tongue had to be very carefully cut off now. 😬😬
That was a loud, dirty and tedious task in itself that took half a day to accomplish without damaging the trailer tongue.
Next, I had to figure out how to mount just the compressor, which was tricky because there really isn’t enough space for it, it needs to be mounted somewhat off center to accommodate the line sets, and it hangs way too far off the tongue.
After drawing up the new mounting system and having the plasma table cut it out of 10ga steel, I put it together and tacked it to the trailer tongue and test fit the compressor. It barely fits.
Then it was time to figure out the propane tank mounting platform-which I wanted to integrate with the AC compressor mounting system-but all the geometry and clearance issues were just too much for me to figure out as one unit so they were built as two separate systems that share some common parts. Here’s the propane mounting “shelf” with a bunch of holes for ventilation that the propane system needs.
Here’s the propane shelf installed.
Then I needed to add some necessary items like access steps, flagpole mount for our Starlink, etc.
Then it had to all get taken apart and painted with some Krylon rattle can.
While that paint was drying, it was time to move to the inside portion of the install, which would prove to have its own unique challenges…