Firstly I totally agree with The BBG and comments on evaporative systems. We have owned two the first for only 12 years then we built again and the second one for 28 years.
We performed annual maintenance and the only cost we had were pad replacements twice. I admit when Perth has several high humidity days it doesn’t work but that is usually only about 10 days per summer so is bearable.
When we built again we planned our home so that it has wide eaves; we have no west facing windows and only one small one on the east. Our north windows are protected by a veranda, our south windows have wide eaves and we have double glazing. Also insulation in the ceilings and its double brick but with a metal roof.
As we are both retired we decided that our 40+ years of loving our slow combustion wood stove was enough and we opted for Fujitsu reverse cycle inverter systems. Only two, one does our combined lounge/dining the second one is in a smaller music / TV room.
The house we demolished had a reasonably new cool only AUS split system which we rescued and have installed in the bedroom; it works really well only needs to be on for approx an hour before bed on 33 + days.
We have ceiling fans which do a great job as inside does not get too hot, in winter we use on reverse. We use the BOM app to check on daily temperatures and if its going to be above 34 we turn on early so stop the house heating up. In winter we use once it gets below 20. We find them efficient rarely having to use above the low fan setting and in winter costs less to run than our pool filter in summer.
We do not use much at night as we’re north of Perth so we usually have that lovely cool sea breeze in the afternoons, we can have 26-28 whilst Perth’s still sweltering at 34-36. So its simple to open up the house to cool it down, whilst closing it up again by approx 8am.
We have had no problems with the Fujitsu and they are 7 years old, the AUS is approx now 11 years also no problems and yes we regularly clean the filters in summer at least bi-monthly due to the high winds we experience and the dirt that blows everywhere.