Someone said Japan used to be in the title - and now that it isn't - I think it should go back. HN is mostly a US based website (with an emphasis on Silicon Valley). This methodology is wildly uncommon in the US. There's very little likelihood this kind of thing would happen in well over 90%+ of the USA. First off - if you're renting - you're not putting holes in the walls that go to the exterior and there certainly…
Meh. Only relevant if you need to pull more than 15A or so. There are plenty of portable air conditioners for sale in the US and most are happy with 110V and less than 15A.
> HN is mostly a US based website
This sounds like gatekeeping. There are lots of readers from all around the world.
> Secondly - you're not hanging air conditioning units off the exterior walls of the apartment
In the US. This is not particular to Japan. In fact, I'd argue that this is the most common air-conditioner setup worldwide, with building in many countries providing supports for either split systems or, more commonly, 'window' units.