Ductless Mini-split AC clearances

[sharpstick]

The specs for the mini split units I've looked at call for considerable clearance to the rear of the outside AND inside units. Typically about 12" and 7" respectively. How necessary is that? having that much clearance on my 14' Burro is difficult. I'd like to mount the compressor unit on the tongue close to the camper body. Do they exhaust to the rear? And for the inside unit, I'd like to mount it right to the upper part of the front window, with appropriate support rails. If I try to mount it with 7" behind it, it will be hanging down so close to the dinette table that we will be bumping our heads on it.

[redbarron55]

My unit requires clearance on top of the inside unit and blows out in front.
Look at my pictures because I don't have the total required clearances but it works ok.
Remember the RV is a LOT smaller than any room it might be mounted in.
U
The outside unit pulls air in at the side and rear.
I have clearance but not as much as the book calls for since air will also have airflow from under the trailer.
The LP tank sits in front, but it is round and I don't think it interferes much with the air flow.
I find that with the inverter control the unit rarely runs wide open anyway.
Usually the outside unit is just moving a small amount of air..
I wouldn't worry if you don't have the full clearance for the manual.
It may not be as 's efficient but it will probably be better than a rooftop unit anyway.
My unit is rated 20 seer and no RV unit I am aware of is that good.
My unit peaks at around 9 amps maxed out and has no starting surge since it is an inverter unit.

[sharpstick]

Originally Posted by redbarron55

My unit requires clearance on top of the inside unit and blows out in front.
Look at my pictures because I don't have the total required clearances but it works ok.

Where are your pics?

[gordon2]

Originally Posted by sharpstick

The specs for the mini split units I've looked at....

Seeing how this is a camping trailer forum and mini-split AC units are very rare on them (at least for now), you might also want to check over at HVAC-Talk: Heating, Air & Refrigeration Discussion

There are a number of true professionals in the HVAC field on that forum who are happy to help (and a few who might be quite aggravating).

[sharpstick]

Originally Posted by gordon2

Seeing how this is a camping trailer forum and mini-split AC units are very rare on them (at least for now), you might also want to check over at HVAC-Talk: Heating, Air & Refrigeration Discussion

There are a number of true professionals in the HVAC field on that forum who are happy to help (and a few who might be quite aggravating).

They have a fairly strict "No DIY" policy and I was encouraged to go elsewhere.

[Kenny in Ohio]

Sharpstick,

I have a mini split in my home, it is great. If an HVAC manufacture of mini splits where to make a scaled down, RV specific unit they could become millionaires.

KVJ

[tractors1]

Installation of a Fujitsu 9RL2 120VAC 9000 btu in an Escape. Nice thread, good pics:

Custom Air Conditioning Retrofit - Escape Trailer Owners Community

[Wayne Collins]

For a truly custom made, or fitted, Air Conditioner that will fit in small spaces, yet have great performance, and be able to stand vibration under rough travel conditions, check out RedDOT Corp, from near Seattle, WA. RDAC.COM
They are a major supplier the the semi tractor/trailer, motor coach and bus, Agricultural, Heavy Equipment industries. As far as I know they use engine driven or hyrdraulic driven compressors. But may also use electric drined ones too. Your Ductless -Mini-Split systems are desighned for home use, where the components are not exposed to vibration and impact. The internal parts may fail over time in a mobile application. Likewise for "window" A/Cs

[redbarron55]

Do a search for redbarron55 pictures.
I have my build in my albums and on many other threads on the subject.
I would post them here, but I am on my phone.

[redbarron55]

[Davie B]

I really like the tongue mount for both the condenser and the water heater. Well played!

[saucesquatch]

redbarron55, I'm very interested in taking the same approach on our Casita. Can you post a picture of how you are running the duct work for the air?
I can't tell from the photo but are you running a 3" or 4" duct under the camper?

[gordon2]

Originally Posted by saucesquatch

...
I can't tell from the photo but are you running a 3" or 4" duct under the camper?

As I understand it, this is a duct-less system. You only need to run refrigerant and electrical lines, and a drain from the indoor unit.

https://www.youtube.com/watch?v=ozaw9QhxkQU

[redbarron55]

Ductless system there is a 1/2" and 1/4" refrigerant lines and a small 4 conductor cable (I think) for power and control of the system.

[saucesquatch]

Good link, thanks!

That explains quite a bit, I appreciate it.

I am still curious how those refrigerant and drain lines are running from the outside on your install.

[redbarron55]

The refrigerant lines duck under the shell and go up inside my cabinet on the driver's side and then through the upper cabinets to the rear.



The lines go up through this compartment (Not stock)
and down the cabinets on the left in this picture. If you look closely you can see the black insulated lines behind the door opening to the right.



The condensate drain goes down the back of the interior of the shell and through the floor.



You can see the tube running to the right of the inside unit along the back wall and through the floor.
I put a screen bag around the drain at the bottom to keep bugs from blocking the tube.
If you look carefully you can see the lines through the opening right of the unit.

[saucesquatch]

Well done, that looks nice and tidy!

I'm glad to hear it can be run through the inside, I assumed it would be much bulkier and wouldn't be able to be hidden. We won't be able to take on this till next spring but I think this is the way to go since our roof is not reinforced for a top unit.

Much appreciated!

[redbarron55]

You could run the lines under the camper, but you would have to run them where they would not be damaged.

[Davie B]

Originally Posted by redbarron55

The refrigerant lines duck under the shell and go up inside my cabinet on the driver's side and then through the upper cabinets to the rear.



The lines go up through this compartment (Not stock)
and down the cabinets on the left in this picture. If you look closely you can see the black insulated lines behind the door opening to the right.



The condensate drain goes down the back of the interior of the shell and through the floor.



You can see the tube running to the right of the inside unit along the back wall and through the floor.
I put a screen bag around the drain at the bottom to keep bugs from blocking the tube.
If you look carefully you can see the lines through the opening right of the unit.

What is the blue hose or cable used for? It appears to have a motorized winder?

[redbarron55]

The Blue(ish) hose on the electric reel is the gray and black water drain hose. If you look closely you can see the added hatch cut through the shell. There is a second reel and hatch in the rear for the potable water hose and electric reel.
(I got a deal on the two electric hose reels off ebay)



The hose is fed from a macerating pump installed under the floor on the driver's side.
This is possible because when I built the bathroom I installed a black tank at the same level as the gray tank in the rear.
There is a connecting line from the front to the back with shut off valves for each end.
The blue line is the drain from the sink and from the pump that empties the shower pan. A Hepvo drain trap acts as a check valve to keep the shower drain water out of the sink



You can see where the outlet from the pump goes up through the floor where it loops through the under sink area and through the bulkhead to the hose reel inlet.







The 3" standard black and gray tank drains are modified with a 1 1/2" hole cut and an ABS pipe glued in with ABS cement and ground up ABS to make a Tee to feed the 'Stuff" to the rubber sanitary tee that feeds pump.
The pump is slightly higher than the drain pipes, but I still get a good pump out.
No fooling with the "stinky Slinky" and putting it away.
I drain the black tank first and then flush with the gray tank.
Works good and no mess.