Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.
Yesterday is not the first time I've considered fitting one to my shed.
Where I live it is very dry, summer and winter. Those evaporative coolers are prevalent here, howeveer, they are not the type I am talking about. People swear by them but I know enough about thermodynamics that I thimpfk it must be mostly psychological with a tiny bit of reality. When water evaporates, it sucks out the heat from what ever it is evaporating from. (boiling water may be viewed that the steam is removing heat). But then the wagter vapor is blown into your home or whatever--that means that heat that is taken out of the absorbing material is blown right into yuour home. The water has such a high heat of transition from water to vapor that it actually DOES cool a bit but the major place that is actually cooled is in th eabsorbing medium. What I am proposing is to take advantage of that mechanism, that is, putting pipes inside the absorbing medium which cools th ewater inside the pipes and is circulated into a radiator in your room then heat exchanged by means of a fan. Much more efficient but a pain in arse to make--not terrible but definitely a day or two's work. Why this idea is not commercially available, I can only guess that the setup wojuld require some kkind of hole in your house (or an krackt open window for two hoses), the hoses being traipsed around, the radiator and it's setup.
There is a third option involving a regular airconditioner--that is, an improved one using the same method of evaporation. As you know, airconditioners take water out of the air and drip it outside==well this is a terrible ineficiency. If hyou capture that water and spray in on th e cooling coills on the outside of your window (or whatever), the cooling coils cool MUCH faster thus saving yuour airconditioner the work of compressing ghe internal gasses to a higher pressure (which releases the heat from your house to the outside). In horribly hot places this would be a great alternative to letting the water drip out on the ground. If one doesn't have enough moisture in the air, use distilled water.
I have a friend in Tamworth.