They are called Evaporator Units. We got one right after we got married and took it with us when we moved to California. The people thought we were nuts but the neighbors liked to come visit in our cool house.
Unfortunately those types of units caused a lot of illness.
“Evaporative units used for home air conditioning are a potential source of Legionnaires’disease.”
Remember the BIG break out of Legionnaires years ago? They had these units on the roof tops.
Yes, Evaporative Cooler Units.
We called them Swamp Coolers as they put moisture in the air and straightened our hair. LOL