When you have multiple rooms to heat or cool and don't want unnecessary external units, then why not use a multi head system? You can attach up to 4 indoor head units to a single external unit which as it is designed with multiple compressors and be used to heat and cool different rooms simultaneously. All the "F" Series multi split systems are made by Fujitsu and are inverters for maximum energy efficiency and minimum noise - you can even combine different types of indoor evaporator units together on the same system so for example you could have a wall mounted, a ceiling cassette and a floor ceiling type all powered by the same external compressor. All have a full range of comfort features including Sleep, Superquiet, Variable air flow and all have an energy rating "A".The F series has 3 basic configurations : AOY50Ui2F : 1 outdoor & 2 indoors units with a total max power of the indoor units between 4.4kw and 7.1kw AOY71Ui2F : 1 outdoor & 2 indoors units with a total max power of the indoor units between 4.4kw and 8.1kw AOY80Ui2F : 1 outdoor & 3 or 4 indoors units with a total max power of the indoor units between 7.9kw and 14.3kw As there are a significant number of options for this type of system, please contact us with your requirements and we will be happy to quote.