I know this sounds like a stupid question but I need some help.
Is "air conditioning throughout" the same as "evaporative cooling throughout"

Thanks in advance

No, they are very different.

Look at the bottom of this page for a summary of advantages and disadvantages:
http://en.wikipedia.org/wiki/Evapora...rative_cooling

Evaporative cooling would be pretty ineffective on a humid summer evening in Qld.

The best you can get is termed as ducted air con, which means every room in the house is cooled. Typically I find australian houses normally have air con only in the main living room and not in the bedroom as well, it takes a lot of searching to find a cheap place with air con in main room and bedrooms to.

Thanks for your replies, I have had a good read of the info... Just wandering what is it like in Melbourne in the summer if you only have evaporated cooling. opinions appreciated.

Many Thanks

Just my opinion - I live in Sydney which is usually hotter than Melbourne, and we get on fine with just a fan, no aircon.

Melbourne is not very humid at all I don't think, evaporated cooling should do the trick there.

Evaporative cooling begins to struggle at about 35 degrees C. Temperatures below that it should be sufficient.