Humidity is low here in the Central Oregon desert and swamp coolers work great. My house is off-grid solar powered so in order to save energy I modified the swamp cooler by installing a motor and controller out of a treadmill. The original induction motor had 3 speeds and was very inefficient but the treadmill motor is a variable speed perminent magnet 2 hp. and very efficient. It runs off my battery bank through a large inverter at 110 volts.