I have been working in the air-con industry for 15+ years now. Refrigeration mechanic by trade but worked my way up over the years to a Project Manager now. Started out doing domestic but now do large commercial projects, if you want any free non biased advise I am happy to help, pm me.
Evaporative:
+ cheap compared to reverse cycle. (fully ducted for average 4x2 for $4-$6 g).
+ nice if you want to have your doors and windows open.
+ cheaper to run (approx 50 cents a day).
- only cools the air about 10 degrees cooler than the ambient.
- no good at all on a humid day.
- should be serviced twice a year (average $100 each time).
- no heating.
Refrigerative:
+ heating and cooling (cooling only models are about $100 cheaper).
+ outside temperature and humidity will not affect its performance.
+ choose the exact temperature you want.
+ great to add value to your home.
- expensive compared to evaporative. (fully ducted for average 4x2 for $10-$14 g).
- need to keep doors and windows closed.
- average running cost for a 12-14kw will be $2-$4 a day.
- really should have your house well insulated or running costs will blow out.
IMO - reverse cycle is the way to go.
Ducted is great, but expensive, even if you have a smaller unit (you can only go up to about a 12kw on single phase power, any bigger and you need three phase) for your average 4x2 you will only be able to run 2 out of 4 zones at the same time.
Generally a 4x2 will be zoned;
1) master bed / study
2) bed 2 / 3 / 4.
3) kitchen / meals / family
4) theatre or games.
So you need to think about what areas you will want on and at what times, depending on how your household works.
If its just you and your misses in bed at night or watching a movie then you will be running a big 12kw unit to cool just the one room you are in. if you have the wife and 2.5 kids then it would probably be the way to go.
Refrigerative wall splits or cassette units could also be the best option cheaper initial cost as you can do one at a time. If you are only in one room at a time then you will only be running one small unit at a time so the running costs will be lower $1-$2 a day.
As far as brands go, what makes a good a/c unit are;
1) Cheap running costs.
2) Quite noise level when running.
3) Reliability.
As mentioned several times above Daikin is number one and I also strongly agree with LG being the best "bang for your buck" unit.
Panasonic, Fujitsu and Hitachi are also good units that I would recommend. Stay away from the brands you have never EVER heard of before.
As for installation, do your home work and get everyone to quote on the same thing, compare oranges with oranges; number of zones, number of supply grills, size of the unit etc... most places will give you a couple of prices for the same install but with options on different make units. Tell them what you want not what they want you to get.
I don't have much to do with the domestic scene these days, so not sure of all the companys out there, but I would recommend Ford and Doonan as providing a quality job.
Unfortunately, as with most things in life you get what you pay for, so just make sure you know what you want first.
Hope this helps.
