Thanks!! Yeah a decent amount of planning went into that with help from people on here. Its pumping that air very well!

Thanks! Yeah out of those options I felt like under the bus was better. I was reading a lot online with this one and it seemed to be drawing between 900-1000 watts while running. I did run the duct work without the dampers(they didn’t come in yet). And it seems to be very even. I havent really run it on the highest speed. The medium fan speed seems to be pushing a decent amount of air.

​@@DanZalinsky When those long runs are complete, you are likely going to need to balance the air flow back to front. When we install ductwork in a house, dampers are always used. I'm a little worried about that uninsulated flex duct sweating in the summer with the way you are doing your roof insulation. I would at least use insulated duct. If you are planning in using the bus year around, I still think spray foam on the roof would be a very good idea, that said, this is your project and I hope your bus is everything you want it to be. :)

@@danp762 Hey, yeah i will be testing the flow to see where dampers will be needed. The elastomeric paint on the roof dramatically helps reduce the heat that gets transferred into the bus. I have 1 1/2" foam board on the ceiling as well. There isnt enough room in that area for an insulated duct so I will try to put insulation in any open space up there and see how it is. The ceiling panels will be easy to remove to maintain anything up there too.

​@@DanZalinsky ​ With unisulated duct all the insulation needs to be between the outside wall that the duct or there is a risk of sweating. It needs to be in the conditioned space. If you are running that duct in a unconditioned space, which you are, it needs to insulated. I'm sorry to say elastomeric paint isn't insulation. I don't keep coming back to closed cell spray foam to be a know it all - but knows nothing. It really will make that much of a difference, on the roof exceptionally. What could easily happen with uninsulated duct is sweating on the outside in the summer and sweating on the inside in the winter that leads to mold problems. I'm done going on about it, you can take my advise or not, it is your bus after all. I just want see something amazing at the end of your build.

@@danp762 I appreciate all the feedback. With all the work in the ceiling its impossible to add spray foam. The foam boards up there have an R value of 7 at 1.5 inches. These are foam boards that are on the very top of the interior of the bus (insulation between the outside and inside). The space with all the duct work will have a vent in the front and back to allow airflow from the front to the back of the bus. I can always tee one of the ducts to vent a little into the ceiling space to allow for a conditioned area up there.

That was the initial plan. But after talking to a friend who is an electrical engineer, I was told to buy a step up transformer. I think that was mostly because the Multiplus only put out 120v and not the 240 that the Minisplit required. It has been running great with the transformer from the 120 breaker.

The ducted minisplit that I wanted didnt come in 110v. So thats why i needed the step-up transformer.

No issues with it at all.

@@DanZalinsky I’ve tried to go from an inverter to the step up transformer, the mini split doesn’t seem to like it, how are you powering the transformer?

@@jerechonatonton1868 I went from a multiplus into a breaker box. I then ran a line from a breaker to a 15A outlet and then plugged the step up transformer into the outlet