I recommend reverse cycle air conditioning units as they can be much more energy efficient than other cooling and heating systems. A model suitable for the layout of your house with adequate capacity for your needs, ensures the climate is controlled for optimum efficiency throughout day and night. - MitchellMc
We're in Melbourne and installed a couple of Jetmaster units when we renovated about eight years ago. They are certainly not a cheap option to buy, and like any gas appliance, regular servicing is recommended. But they are relatively cheap to run, look fantastic and it’s a lovely heat. People have even mistaken them for a real fire, particularly as we installed one of the units in a crazy-paved fireplace which looks great. They are the only heating we have in the house and we would do the same thing again. We particularly like having the main unit in the living area on a timer so it automatically comes in before we get up in the morning and again in the late afternoon before we get home.
Hydronic is a lovely heat and very efficient. You can zone your house so you don't have to heat the whole house when its on. Most systems use gas boilers and are reasonably affordable to run. Unlike many other heating options there's no fans blowing air and dust around so they are great for asthma and allergy sufferers and make no noise. It's a great option if you have the wall space in your house (or are building new and can do in-slab) and can afford the significant installation cost. Probably the only other significant weakness is they don't provide 'instant' heat and obviously can't cool your place as well like some reverse systems can. - Kermit
I use reverse cycle and that works great. Cools in summer, too. - JohnL2120
I know plenty of people like ducted but I don't like the dust they tend to blow around. I would also prefer something that you can stand in front of when you get cold. - Joker