I like the idea of getting a portable Evaporative Cooler unit first and try it out before going into alot of changes...
Lived in AZ in the 60s and 70s and you really have to learn how to use a Evaporative Cooler...
For us they worked the best at night working with cool night air being drawn in from the outside... Once you figured out how the the house breathes the best then they work great... Nothing instant about them however...
The part I really didn't like about them in AZ is most were installed on the roof of the house and one had to arm himself with insect spray and other means of protecting yourself to do minor maintenance. This was the favorite spot for Black Widow spiders haha Once you got all of them killed off then you could replaces the filters as required etc...
Being an outdoor type person I really liked them the best at night... The idea is to draw in cool night air and have it blown back at you through the vents from the cooler fan...
Being light weight and the fan and water pump running from 12VDC makes it ideal for back road camping. They only work in low humid places however...
Roy Ken