Shuttle Bus Mini Split

[cadillackid]

if its an american TV show you always save the red white and blue wires if you have to cut one then cut any other color

 

[kidharris]

True, just trying to avoid lingering misconceptions. ;>)

Thanks, I was confused because I thought transformers were for changing ac voltages so I was beginning to wonder about this threads validity. reading minds is not my strong point so I was chalking it up to bs

 

[kidharris]

if its an american TV show you always save the red white and blue wires if you have to cut one then cut any other color

thanks for clearing that up, usefull info if I ever have to save the world.....again

 

[skydawg]

My own experience with a 12k BTU (115v) Pioneer unit so far:

- 14,400Wh (at 48v) battery storage
- 1600w of solar panels
- unit is rated for 12.7 amps @ 115v
- 6 row bus (~19 foot cab)
- *** bus windows skinned over and spray foam insulation applied ***
- edit: insulation is 1" xps foam board on the floor, 2-2.5" spray foam walls, 1-1.25" spray foam ceiling

Cooling -
My unit is having no issue keeping things comfortable while cooling on sunny days while stationary, with enough power to run my 115v refrigerator and anything else in the bus while also still charging batteries. I am at 100% SOC by early afternoon (assuming I ended the previous evening the same). Even an entire week of overcast weather still had me hitting 90+% SOC by sunset (runs less when overcast, which is probably part of it).

It uses significantly more power if cooling while driving down the road (runs more) and does not keep it comfortable unless I am running additional fans to distribute the air (talking 90F+ days).

Heating -
This was pulling nearly the max rated amps while stationary. Combine that with short winter days with less sunlight, and I doubt the panels are going to be able to keep up (I have not had a chance to test this over a winter yet). I expect I might need a generator to keep things going.


Other thoughts....

I mounted the outdoor unit directly behind the rear differential under the bus. It has survived over 2500 miles there so far, but I am very anxious about how long it is going to last. Mini-splits are meant to be mounted on a concrete pad or relatively stable location... I shook the absolute **** out of it (no air ride) running the I-70 washboard in Colorado at 70-75mph. I cannot believe it is still working, to be honest.

Does anyone know of recorded failures of the outdoor unit in a mobile application?

 

[ewo1]

My own experience with a 12k BTU (115v) Pioneer unit so far:


- 6 row bus (~19 foot cab)
- *** bus windows skinned over and spray foam insulation applied ***

Cooling -
My unit is having no issue keeping things comfortable while cooling on sunny days while stationary, with enough power to run my 115v refrigerator and anything else in the bus while also still charging batteries. .....

It uses significantly more power if cooling while driving down the road (runs more) and does not keep it comfortable unless I am running additional fans to distribute the air (talking 90F+ days).

This is some really good info for those who are looking to cool their bus with mini splits while driving.

@skydawg, in your experiences with your bus, assuming a 40' bus, how do you think 2 - 12k mini splits would cool a bus with 90+ degree temps, windows skinned and insulated ???

 

[Blubus]

My own experience with a 12k BTU (115v) Pioneer unit so far:

- 14,400Wh (at 48v) battery storage
- 1600w of solar panels
- unit is rated for 12.7 amps @ 115v
- 6 row bus (~19 foot cab)
- *** bus windows skinned over and spray foam insulation applied ***

Cooling -
My unit is having no issue keeping things comfortable while cooling on sunny days while stationary, with enough power to run my 115v refrigerator and anything else in the bus while also still charging batteries. I am at 100% SOC by early afternoon (assuming I ended the previous evening the same). Even an entire week of overcast weather still had me hitting 90+% SOC by sunset (runs less when overcast, which is probably part of it).

It uses significantly more power if cooling while driving down the road (runs more) and does not keep it comfortable unless I am running additional fans to distribute the air (talking 90F+ days).

Heating -
This was pulling nearly the max rated amps while stationary. Combine that with short winter days with less sunlight, and I doubt the panels are going to be able to keep up (I have not had a chance to test this over a winter yet). I expect I might need a generator to keep things going.


Other thoughts....

I mounted the outdoor unit directly behind the rear differential under the bus. It has survived over 2500 miles there so far, but I am very anxious about how long it is going to last. Mini-splits are meant to be mounted on a concrete pad or relatively stable location... I shook the absolute **** out of it (no air ride) running the I-70 washboard in Colorado at 70-75mph. I cannot believe it is still working, to be honest.

Does anyone know of recorded failures of the outdoor unit in a mobile application?

Our Pioneer mini-split is also mounted behind the rear axle. It sits directly behind the mudflap and hasn't failed us yet. It's been back there for several thousand miles and 6 years now!

 

[skydawg]

This is some really good info for those who are looking to cool their bus with mini splits while driving.

@skydawg, in your experiences with your bus, assuming a 40' bus, how do you think 2 - 12k mini splits would cool a bus with 90+ degree temps, windows skinned and insulated ???

If you are talking about while stationary, I would think it would be plenty based on what I have experienced so far.

If you mean while driving, it is hard to say. When I say it was mostly comfortable with an additional fan, I am talking a high air volume box fan directly on the driver area. Do you want it tolerable (your back might be slightly perspiring from the seat fabric), comfortable (no sweat), or actually "cool" (72ish)? I would think it would be at least tolerable to comfortable, but you might wait for someone with a larger bus to weigh in.

My single unit in a six row bus was alternating between tolerable and comfortable depending on how much sun I had in the cab. The thing about driving my bus which didn't really click until I had put some miles on it is that it does not have any sort of dashboard like a car would have to temper the incoming sunlight and also has a very large windshield area.... which means that certain times of the day the sun is directly in your lap. That quickly makes things warmer than they should be for the driver, but passengers might be good

 

[Mr P]

You said "spray foam". How thick, please?

 

[skydawg]

I actually did not go crazy with insulation since I did not do a roof raise.

I have 1" XPS foam board on the floor with the 3/4" advantech on top.
On the roof, I only did spray foam flush with the ribs (about 1" depth) and left a very thin overspray covering the surface of the ribs.
For the walls, I asked for 2" but spray foam is far from precise while being applied, so some of it is likely up to 3-3.5" and some a bit less than 2". I did have it done professionally (no DIY kit), so it is likely somewhat better quality than you would end up with doing a kit.

 

[Mr P]

FWIW, my Thomas "ribs" (hat channel) is very close to 2". What body have you got?

 

[skydawg]

AmTran body. It *might* be like 1.25-1.5" but it was definitely less than 2.

 

[nikitis]

If you had 4inch floors xps, and 2-3 inch foam walls, it'd probably work while driving.

 

[Mercuric Mind]

I have a 30 foot thomas freightliner with 2" spray foam and an additional 1-1/2" fiberglass batt insulation. I have a 240v 9000btu mini split. It works great to cool the bus stationary or moving. It does struggle a bit when it is above 95 and super humid. I would suggest to use a 12K btu unit as the minimum in most anything.

 

[skydawg]

If you had 4inch floors xps, and 2-3 inch foam walls, it'd probably work while driving.

Possibly, but I am not convinced my issue is related to the areas I have already insulated. It might be ok in the rest of the bus, but I cannot say since it's hard to relax in the back and drive at the same time

I would say the weak cooling while driving (in my instance) is partially from the fact that the mini-split is mounted above the rear emergency exit door (hence why I need fans to move the air the the front while driving), in addition to not having fully insulated the driver's area or wheel wells yet, not having done anything additional with the doghouse, and not having sealed off the fresh air vent at the driver's blower motor. My bus is still quite a ways from being finished.