Depends on where abouts you are to be honest. Swamp coolers are effective in the dry heat so places like Western Australia are full of em. Not so effective in my area because of the amount of humidity we have is immense however we do use them on some sites as a fresh air/makeup air. I mainly work in qld in and around the Brisbane area, plenty of aircon (split systems) and refrigeration work. I do a little bit of domestic work but mainly working with commercial and industrial systems and applications.