Mini Split AC Installation

[ComfortEagle]

I am starting a (another...) new thread to document the the install of our mini split. The unit we are installing is a SuperAir 12,000 BTU unit we got from Amazon...


The mini split will be our sole source of air conditioning and an "auxiliary" heat source. We chose this particular unit in large part based on Juan's recommendation:
https://youtu.be/GvdIe0AkXV8

The indoor unit will be mounted above the windshield. I will be building a box around the upper intake of the unit.


I left a portion of the hinges (to the original large cabinet door) in the top of the opening. I plan to cut the metal door into pieces and re-use them on either side of the mini split.




The outdoor unit will be going into the driver side front storage bay.


The mini split outdoor unit is a smidge too tall for the bay. To overcome this issue and to add more ventilation, I completely removed the floor from the bay.

The bay is reinforced with Superstrut (Lowes Unistrut) and the unit now sits ~2 inches lower.




I will eventually be adding a screen "floor" to the bay to keep out critters. I will also be (attempting) to cut out the bay door and installing metal meshing for ventilation.

Of course the big question is, will I be able to run it off solar...? #foolserrand

[john61ct]

Yes, you have plenty of room up top for 1200+W of panels.

This will run the aircon when sitting in bright sunlight, with just a small battery as a buffer.

If you want to "timeshift", you will get say an hour of aircon per 100AH of dedicated bank capacity. Depending on weather, angles etc maybe 5-7 hours a day.

Lots depends on how big a space you're trying to cool, how thick and well sealed the insulation, gap between ambient temps vs thermostat.

You will not be able to run the aircon off the panels **and** recharge a large bank at the same time, unless going to maybe 2-3kW of panels.

Running off genny will be needed for sub-optimal conditions, so the large investment in solar+batteries+inverter in the end just reduces your genny runtime.

[ComfortEagle]

Originally Posted by john61ct

Yes, you have plenty of room up top for 1200+W of panels...

John you fell for it, flushed you out with my cunning ruse...#foolserrand

Anyway, I cut up the big door up last night. Here are a few pics with the "new" left and right cabinet doors mocked up.


Here is the left side, door zip-tied in place. The three light colored circles on each door are from grinding the hinge rivets off...


More to come...

[Juicifer]

Yes!! Finally I get to steal an idea from you! I have my first mini split sitting under the bus waiting for metal fabricators to stop no-showing on me. If it keeps happening maybe I'll go the unistrut route. Keep up the good work!

[ComfortEagle]

Originally Posted by Juicifer

Yes!! Finally I get to steal an idea from you! I have my first mini split sitting under the bus waiting for metal fabricators to stop no-showing on me. If it keeps happening maybe I'll go the unistrut route. Keep up the good work!

Thanks brother, it's nice to be spending quality time on the bus again.

I finished up the bay design and build work yesterday, and then I "installed" the outdoor unit to the bay. Although it is not plumbed or wired yet, it is satisfying to see the mini split on the bus, even if it is just a mock up at this point...


As previously mentioned, the insufficient ceiling height drove me to remove the bay floor. With the bay door open and floor removed, I don't think air flow will be a problem. I am not looking forward to cutting up that door...

[cadillackid]

nice looking install.. but with the outdoor unit in that cabinet how are you going to have A/C for driving? even cutting the door you arent giving the unit much chance for airflow when moving.

-Christopher

[ComfortEagle]

Originally Posted by cadillackid

nice looking install.. but with the outdoor unit in that cabinet how are you going to have A/C for driving? even cutting the door you aren't giving the unit much chance for airflow when moving.

Thank you for your comments. As I mentioned, this will be our ONLY source of air conditioning, period, so we will need it while driving, and yes I am very concerned about airflow.

As for clearances around the unit, with the bay floor removed and the door cut out, the unit meets (more or less) most clearance requirements EXCEPT height.



Controlling air flow going down the road (which I believe is your concern?) is another story... Maybe it will be fine as is? I will need to study the actual airflow in that bay as the bus is going down the road. Between some type of air ducting and a few small fans in the bay, I think I can work it out.

[peterbylt]

Your installation is very similar to mine.
I currently have one Pioneer 12,000 110v inverter unit installed in the Front, the long-term plans call for a second unit to be installed in the rear.

Both the Generator and the outside unit of the Mini Split need to cohabitate the driver’s side of the front Luggage Bay.
I have divided the bay in half with a ¾ inch plywood wall.

The installation is not totally complete yet, the unit is up and running, over the course of a couple of hours it will bring the entire heat soaked bus down to 75 degrees in 90+ degree Florida weather.

After much though I decided to mount the Condenser (outside unit) sideways, for now the bay door needs to be opened, I plan to replace part of the skin of the Bay door with expanded metal to match the OTR air bay door just in front of it.

The most difficult part of the installation was running the 25 feet of copper tubing without kinking it, Lots of bends and turns.
I will only be using the Mini Split while stationary the Over the Road Air still works great and I plan on keeping it.

So far I am very happy with the Mini Split, The single unit works good enough that the install of the second unit is not a priority.





Peter

[ermracing]

How quiet is the condenser?

[peterbylt]

Both the condenser and the evaporator (outside and inside units) are so quiet you can barely hear them.

Peter

[ComfortEagle]

Originally Posted by peterbylt

Your installation is very similar to mine.
I currently have one Pioneer 12,000 110v inverter unit installed in the Front, the long-term plans call for a second unit to be installed in the rear.

Both the Generator and the outside unit of the Mini Split need to cohabitate the driver’s side of the front Luggage Bay.
I have divided the bay in half with a ¾ inch plywood wall.

The installation is not totally complete yet, the unit is up and running, over the course of a couple of hours it will bring the entire heat soaked bus down to 75 degrees in 90+ degree Florida weather.

After much though I decided to mount the Condenser (outside unit) sideways, for now the bay door needs to be opened, I plan to replace part of the skin of the Bay door with expanded metal to match the OTR air bay door just in front of it.

The most difficult part of the installation was running the 25 feet of copper tubing without kinking it, Lots of bends and turns.
I will only be using the Mini Split while stationary the Over the Road Air still works great and I plan on keeping it.

So far I am very happy with the Mini Split, The single unit works good enough that the install of the second unit is not a priority.

Peter thank you for sharing your install. It's cool (no pun intended) that you will only need the mini split while stationary; no OTR air conditioning for me in the Gillig. And yes, I am very apprehensive about running that copper tubing.

I see you are converting a coach; I have been following this coach build out in AZ. I am actually using the same mini split as they did...

Originally Posted by ermracing

How quiet is the condenser?

Skip thru the below video and there is a demo of the installed mini split; it is very quiet...

https://www.youtube.com/watch?v=GvdI...ature=youtu.be

[ermracing]

Is the standard 15' hose long enough for installation with the compressor down below? They have a 25' upgrade. I was measuring our bus and the 15' may fit, depending which sides of the units they connect to.

Dave

[rebapuck]

Remember the old VW buses? (I still got mine) Some increased engine air flow with scoops mounted over the side vents. Perhaps that would work for you.

[cadillackid]

Remember to add refrigerant per the chart if you increase the line size.. the unit paperwork should have the charge listed and a lineset length for the charge. Also evacuate before releasing the king valves.. skipping this step reduces effiency and capacity.. air in the lines is bad. If you have precharged lines you won’t need to add or evacuate but most aren’t precharged lines

Minisolits can be long lasting efficient units but care needs to be taken at install. I have 3 modified units in my house. Cheap. Chinese units my colleagues said wouldn’t last 3 years are at 10 years and only thing to break is the plastic retaining clips for the fan screens and the cabinets are starting to rust..
otherwise I run em winter and summer..
Christopher

[ComfortEagle]

Originally Posted by ermracing

Is the standard 15' hose long enough for installation with the compressor down below? They have a 25' upgrade. I was measuring our bus and the 15' may fit, depending which sides of the units they connect to.

Dave, mine came with a 25ft hose; I'll let you know how it goes...

Originally Posted by rebapuck

Remember the old VW buses? (I still got mine) Some increased engine air flow with scoops mounted over the side vents. Perhaps that would work for you.

Right. I am ready ready to get creative.

Originally Posted by cadillackid

Remember to add refrigerant per the chart if you increase the line size.. the unit paperwork should have the charge listed and a lineset length for the charge. Also evacuate before releasing the king valves.. skipping this step reduces effiency and capacity.. air in the lines is bad. If you have precharged lines you won’t need to add or evacuate but most aren’t precharged lines

Minisolits can be long lasting efficient units but care needs to be taken at install. I have 3 modified units in my house. Cheap. Chinese units my colleagues said wouldn’t last 3 years are at 10 years and only thing to break is the plastic retaining clips for the fan screens and the cabinets are starting to rust.. otherwise I run em winter and summer..
Christopher

All good stuff; I think call in a pro to do the actual connections...

[ermracing]

Did you buy it through Amazon? How did you get the 25' upgrade?

[ComfortEagle]

Originally Posted by ermracing

Did you buy it through Amazon? How did you get the 25' upgrade?

So, I am a doofus... I had unrolled the lines but hadn't measured them, until right now. The lines are in fact only ~16'5" (5 meters). At this point I am pretty sure that the lines will not be long enough...

[ermracing]

We just ordered the 16 SEER unit (same 12k btu, 110v) unit from SuperAir. They upgraded our order to the 25' lineset for an extra $40. Once we figure out the install of the unit and running the lines we can finish up the ceiling installation.

[BlackJohn]

Trying to decipher if these lines are pre-charged with a quick connect fitting on both ends. Or do you install the lines then fill the system?
I ask because it seems people are afraid of bending them when installing.
There is a way to bend lines of this type without kinks by sliding a long tightly coiled spring over the lines, a tad bigger that the line diameter. This wouldn't work if connectors were on the ends though as the spring couldn't be added over a big connector.

if that is the case there are some nice tubing benders for brake lines, fuel lines and such that will fit anywhere on the ac line so you can bend as much as you want without the dreaded kinks happening.
Never seen a minisplit up close so do not know.




Thanks



John

[Jolly Roger bus 223]

Mini split linesets uasually come pre -insulated. To use a hand bender you would have to cut the insulation and then re-seal it properly in such tight quarters.
All soft copper works better with long radius turns that don't kink which takes up a good bit of room.
The only way to correctly get it tighter into the corners is to use hard pipe fitting and braze them in.
I have successfully?
A few times bent a pre-insulated line set around a piece of 1-1/4"-1-1/2" pipe and just wanted/had to cut the insulation to see what kind of kinks/damage I did . Kinked some and cut it out to fix it? It can be done to get a shorter radius turn but it will never be the same turn as a hard pipe fitting.
There is no such thing as a precharged linesets? There are preset lengths that are already factory cleaned and sealed that have the proper flare connector and nut on them.
But because the line is opened to air to connect them on either end? Then the lines should be vacuumed down to remove any free/contaminated air in them before releasing the factory charge for that pre-set line length of 15-25' or whatever you ordered as for as line length? If you ordered 25 and only ran 15' then your pressure will run a little high and if your ordered 15' and had to add your pressure might seem a touch low but for some units they put a little more in or a little less in? You can get your own gauges and check out what you end up with or you can get someone that says they know what they are doing.
The vacuum pump on the lineset is important to get rid of that big air bubble.
The next is running the communication wires and the power wire.
All brands are different
Some rask for the main power to the outdoor unit and comm wire to run the indoor unit.
Some ask for main power to the outdoor unit and main power to the indoor unit and a 12-24 thermostat cable in between?
Wide range of variations?
Good luck