We've recently moved into a top (8th) floor apartment in a 1930's building in Sydney where we have access to the attic above.

We want to get reverse-cycle ducted aircon installed with the heat pump either installed in the attic (it is well vented) or on a back balcony.

We have original decorative plasterwork on some of the ceilings in the rooms which we want to preserve and so we're looking for mini-duct systems to minimise the visual impact of the vents - but I can't seem to find anyone who does them in the Sydney area - any suggestions or alternative products that don't require large ducts/wall units?