We have a old ducted split aircon installed and now it has been running a bit odd (approx. 35yrs old) It's a single story house (in Sydney) and roof made is same as old house (appro 40 yrs) Australian residential architectural styles - Wikipedia, the free encyclopedia Got a quote from a guy for supply and installation of new Aircon. Daikin(Inverter) 12kw single phase Including 3 X Zoning Total cost $7800 Does this cost sounds ok? Any recommendations on types / brand of aircon? How much this job will cost roughly?