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When we install mini splits we run 12-2 for 18000btu or less and 10-2 for 18k+... This is due to the amperage spike every time the compressor kicks on. You 15amp circuit may pull 70 amps or more when the compressor kick on.... It is also nice to install a quick pull disconnect in the circuit somewhere, oh and rain tight conduit.
I do this stuff every day of the week so if you have any other questions feel free to ask.
Haha... You could build a fan shroud that sucks the hot air expelled from the condensing unit"outdoor part" and duct it outside. You are going to lose effeciency very quickly when it gets hot outside... Or build a room around the condensing unit and move a shit load of air through it. Your best option is definitely to move it outside though... We mostly sell Mitsubishi s and they are so quiet you can't even hear them run when standing next to it.
If you decide to go this route I could draw a wirin diagram that would kick on the fans only when the unit is running.