It uses R-22 so it's pretty old, but probably not 1950s. Maybe 1970s. R-22 was phased out starting in the 1980s, and banned in 2010 (that's in Europe, maybe later in US).
When I lived in the US I tried to get a minisplit and they wanted $4000 for a medium size unit! The same one where I live now is $400 installed.
When I lived in the US I tried to get a minisplit and they wanted $4000 for a medium size unit! The same one where I live now is $400 installed.