[Mib2nd]

Starting on the 24K mini split install in the morning!

Pulling out the old units and I will be fabricating the new return to accommodate the cassette style air handler that will supply the coach with air & heat through the existing ductwork so we don’t have to mount heads inside the coach.

It’s going to be tight, but I have spent hours researching different models and found one that will fit with some modifications I am going to make rebuilding the return. I finally found an HVAC company that is willing to help get it in. Between the two of us we will get it in one way or another.

Will follow up with photos as progress is made and hopefully a video at the end when I get a chance to do the editing.

   
   
   
   
   
   
   
   

[Jack Houpe]

Good for you Jim, the unit you're installing is a ducted unit cassettes normally go in the ceiling. How many zone is the 2-ton compressor? It says deducted unit is 18,000 BTU, need to find out what cfms you have for that unit that may not be big enough to cool your coach.

[hbens]

Hi Jim,
I subscribed to this thread to follow along your journey.
I installed a 20k 2 zone unit in my coach. I'm adding a 115v single zone 12k to the master bedroom in the near future.
Here in the FL sun, or anywhere the sun shines on the coach, the 20k isn't enough to keep it cool above 85* outside. The skin of our coach gets to 135* in the direct sun.
You may have seen my thread on the install. Here is a link.
https://newellgurus.com/showthread.php?tid=7417
Great that your enlisting an HVAC company to help at the onset of your project.

[Richard]

Jim,

Although I have not installed a mini in place of the SCS units, I have had detailed conversations with those who have.

There are two modifications to your approach that you may want to consider. One, use this opportunity to snake one or two additional elephant trunks into the front compartment. Two, install some sort of manual damper in order to balance air flow to the rear plenum and front plenum. Otherwise air will follow path of least resistance which may not cool the coach evenly from front to rear.

[hbens]

Jim,

Although I have not installed a mini in place of the SCS units, I have had detailed conversations with those who have.

There are two modifications to your approach that you may want to consider. One, use this opportunity to snake one or two additional elephant trunks into the front compartment. Two, install some sort of manual damper in order to balance air flow to the rear plenum and front plenum. Otherwise air will follow path of least resistance which may not cool the coach evenly from front to rear.

Exactly what I was thinking but unable to come up with the correct jargon for it. 
Sufficient airflow has been a thorn I have had to overcome.

[[email protected]]

I like the idea of the mini splits but there are some inherent issues that I did not like. So that unit you are putting in looks like it’s 230v? So now you are going to limited to only 50a service, which may not be a big deal for you. Just a thought. I have thought about going with a 230v unit and then putting in a robust inverter that would be able to run the ACs in the event that you can only get a 30a site or power then you could at least still run the airs. Just some of my thought as I have gone through the ideas of changing the units. My SCS units are in pretty good shape. I actually am working on them now adding service ports so I can charge them up.

[HoosierDaddy]

I am following this thread with interest!!

[Jack Houpe]

My wife and I have done 3 retrofits all have been using wall mounted evaporators and just finished up the Prevost bus I personally like the direct exchange of energy rather than having loss due to duct inefficiency but if I where going to do a ducted unit I would use a horizonal air handler from a home unit with a home style blower unit with a variable blower to control the CFM. Mini splits really don't turn off they are running all the time unless the temp gets below your set point, the good part of this is its removing moisture from the air and for us folks that live in the south thats means a lot, being able to slow down the compressor and the blower fan on the evaporator saves energy and its very quite.

https://www.acwholesalers.com/Goodman-CH...6sEALw_wcB