Mounting huge mini split system

[warewolff]

So my 12k btu unit came in today ... I know I looked at the dimensions before I purchased but wow .... This unit is huge. Specs are 21.75in tall, 31.5in wide, 13.125in deep. I worked my way under the bus and while there are certainly a few places it'd fit I'm more worried about it getting filthy and beat up. When installed snug against the inner frame and behind the rear wheels I'll have just 14" or so of clearance between the bottom of the unit and the road. I know aerodynamically it would be a bad idea to mount it right on the side of the bus, but is this a bad option otherwise? It would make for a real easy install. Not too concerned with theft ... I'll mount it up high should I go that route. I know somewhereinusa is running their rig with two mounted underneath but not quite sure if their units are as big as mine. It is huge...

Suggestions appreciated. I'll update my build thread once I get this thing mounted!

[cadillackid]

thats the right size... I have 3 in my house and 2 of them are that size and one is larger..
-Christopher

[Jolly Roger]

Are you talking about the outdoor unit or the unit that should be indoor?
The install instructions are what is best for the unit. Not saying they can't be fudged a little.
Make model style of unit would be nice?
Might have already posted what you bought but time wise for us/me would help if you posted your exact set up and idea's gain?
New stuff and intended locations please.

[warewolff]

Originally Posted by Jolly Roger

Are you talking about the outdoor unit or the unit that should be indoor?
The install instructions are what is best for the unit. Not saying they can't be fudged a little.
Make model style of unit would be nice?
Might have already posted what you bought but time wise for us/me would help if you posted your exact set up and idea's gain?
New stuff and intended locations please.

http://m.ebay.com/itm/PIONEER-12000-BTU-22-SEER-Inverter-Ductless-Mini-Split-Heat-Pump-120V-10-39-Kit-/111902477753?txnId=1668702210001

Specifically referring to the outdoor half, haha. Thanks!

[warewolff]

I should also specify that I originally intended to mount it on the back bumper, then under the bus ... I'm now intending on mounting it right to the side if the bus, over my last and rear skinned window on the drivers side, about 4 or 5 feet up. It would make the total width of my bus almost 9 ft .... I know this is slightly illegal and not ideal but it would only extend 4 inches past my drivers mirrors.

[cadillackid]

thats a really bad place for a minisplit to be.. its likely going to be in the direct wind so much that the unit cant control its head pressure.. or impede the condensor fan and set an error code (shuts down the unit).. at road speed.. plus there has to be I think its 8-12" or more rearward clearance for sirflow.. you cant mount it right up against the side of the bus..
-Christopher

[warewolff]

Originally Posted by cadillackid

thats a really bad place for a minisplit to be.. its likely going to be in the direct wind so much that the unit cant control its head pressure.. or impede the condensor fan and set an error code (shuts down the unit).. at road speed.. plus there has to be I think its 8-12" or more rearward clearance for sirflow.. you cant mount it right up against the side of the bus..
-Christopher

None of the pre-fab'd mounts have 8-12" clearance behind the unit. It looks like the mounts go right up against the wall, giving the unit only a few inches of clearance ... any ideas on how I should tackle this?

[cadillackid]

Originally Posted by warewolff

None of the pre-fab'd mounts have 8-12" clearance behind the unit. It looks like the mounts go right up against the wall, giving the unit only a few inches of clearance ... any ideas on how I should tackle this?

does your bus sit so low to ground or is it super crowded underneath where it cant go underside?

the prefab brackets im not a fan of.. they DO work, I juast know these units want every bit of airflow you can give them.. but it had to be somewhat controlled.. at least underside its not direct wind blowing at them.. its filtered to some extent ..

I just think side mounting is just asking for a DOT stop..

I think it can hang under the skirting a little and bot hurt anything, only other clean method I can think of is back porch style mounting.. ive seen it done before and it looks pretty good.
-Christopher

[Brewerbob]

Originally Posted by warewolff

So my 12k btu unit came in today ... I know I looked at the dimensions before I purchased but wow .... This unit is huge. Specs are 21.75in tall, 31.5in wide, 13.125in deep.

For what it's worth, that's smaller than my OEM basement lockers. They are 25" high, 80" something long and 28" deep I think? I wrote it down somewhere. Would fit in a single bin. So unless you filled your entire under skirt there should be plenty of room for it.

[warewolff]

The best spot for it underneath without running 20 ft of refrigerant line is behind the rear wheels. I was worried about dirt and grime building up on the unit in that space. I suppose I could mount it underneath the bus -- the unit wouldn't come down lower than my rear axle. Still, 15 inches between the bottom of the unit and the pavement doesn't seem like a lot of clearance if I go over a speed bump with a loaded rear.

Lastly, cadillac, I have a friend that can weld some custom brackets but if the ones I have already work you think that would be a bad idea? With it hanging below my frame it would have air flow for sure. I'm just not confident I wouldn't have the same problems with head pressure underneath as it'll be getting wind down there too. I thought somewhereintheusa is still doing this with no problems?

[somewhereinusa]

My front one is mounted in front of axle, rear is where original condensor was behind rear axle. Both are longitudinal. Have never run them while moving.

[warewolff]

Originally Posted by somewhereinusa

My front one is mounted in front of axle, rear is where original condensor was behind rear axle. Both are longitudinal. Have never run them while moving.

Uh oh. If I shield this thing is it possible to run it while moving? Was kind of basing my whole system off that... thinking I made a bad decision now.

[cadillackid]

ive got an inverter compressor portable unit that I hgave run while moving just to see.. and the compressor never shut off..

with a Minisplit its all a matter of airflow.. if the airflow is such that it impedes the fan to where the unit thinks the fan is bound it will toss a code and shut off.. I dont know how sensitive or fancy the computers are in your unit.. mine have sensors for about everything... and they are 8 years old.. best thing is try it.. but I think you;'ll be dissapointed in how little cooling you get on the road... it takes a lot of A/C to overcome road heat..
-Christopher
-Christopher

[warewolff]

Thanks. I found a spot right on my back bumper, just below where the back door opens. It's protected there and I should be able to build a shield out of plexiglass so the unit doesn't have wind forced up into it. The bottom of the unit is about a foot and a half from the pavement there, which I'm pretty happy with. As for cooling, only time will tell. I had hoped that the 12k btu unit would be sufficient, even on the road ... my bus is pretty well insulated at this point. I am honestly getting a little nervous though. Maybe I'll take a trip down to FL sometime and pay you a visit while really testing that notion out =p

[Brewerbob]

Originally Posted by cadillackid

ive got an inverter compressor portable unit that I hgave run while moving just to see.. and the compressor never shut off..

with a Minisplit its all a matter of airflow.. if the airflow is such that it impedes the fan to where the unit thinks the fan is bound it will toss a code and shut off.. I dont know how sensitive or fancy the computers are in your unit.. mine have sensors for about everything... and they are 8 years old.. best thing is try it.. but I think you;'ll be dissapointed in how little cooling you get on the road... it takes a lot of A/C to overcome road heat..

I've no idea what these things look like, how they are configured, etc. but can you just reverse the fan and have it pull air instead of push (vice versa)? Then your road wind would help.

[cadillackid]

the blade shape isnt condusive to reversing the motor direction, plus then you would be pulling dirt in from the front and making it near impossible to clean the coils.. as a puller, the coils are easily hosed down.

for airflow im thinking your best bet is a sideways mount..

if you point the fan inward then you are mimicking how the factory road A/C works.. it pulls air in from the side and blows it out the side or bottom .. build a little grill to keep rocks from coming up and smacking the coil and im thinking you have a good shot at running it while driving.
-Christopher

[Brewerbob]

Side note: I dunno if I mentioned it on skoolie much less which thread if I did but while I was junk yard diving, there was a semi trailer that had a tiny diesel engine for the reefer. The engine looked intact but the compressor was missing so it wouldn't have worked for AC as is. But that little diesel engine was so cute. Little inline 2 or 4 cylinder (I think 4). I forgot my phone in the car or I would have snapped a pic of it. Would have been perfect for driving the extra alternators (in the other thread) or just find another compressor. I need to take a trip back out there and at least get the mfg name off the reefer. The engine couldn't have been more than 8-10 inches wide. Maybe 20 inches long and 20 inches tall. Not sure if it was as tall as it was long. Anywho, it would fit damn near anywhere in a skoolie project.

[cadillackid]

some busses that people have gotten here on skoolie came with a little mitsubishi diesel engine that spun 2 A/C compressors..

other things like it are Tri-Pak style systems like truckers yse... many have a 12,000 BTU A/C comopressor with them.. its a small 2 cylinder diesel engine that either runs an alternator to generate power for an electric A/C or uses a standard belt compressor.. ive seen both.. most commonly a DC motor compressor.

-Christopher

[Brewerbob]

I wanna go back and take a pic of it and ask the dudes how much they want for it. If it's more than $100 they can keep it especially if I have no way to start it. But if they only want $25 for it, I'll take it home as a coffee table centerpiece or something.

[cadillackid]

Originally Posted by Brewerbob

I wanna go back and take a pic of it and ask the dudes how much they want for it. If it's more than $100 they can keep it especially if I have no way to start it. But if they only want $25 for it, I'll take it home as a coffee table centerpiece or something.

its unusual for someone to throw away a reefer that works .. the fact its comoressor was gone makes me wonder if the engine is popped..

-Christopher