Hi Tim, We'll be doing our renovations soon and would love some help in recommendation and costs related to system 4 inverter aircons. This is for a maisonette. The aircons will be in living room, masterbedroom and 2 other rooms. The masterbedroom is a combination of two rooms. So I guess, somewhere along these lines: Living room - 24k BTU Masterbedroom - 18k BTU 2 rooms @ - 9k BTU each many thanks!