Pretty straightforward science and application on the evaporative cooler (only people in the West know what this is, I bet). Outside air, forced inside by a squirrel cage fan, being drawn through (fairly) fresh water-soaked pads of aspen fiber or specialized material, is cooled because the originating air is somewhat "dry," that being, air that has a measured dewpoint below around 55 degrees. Really dry air, like when the dewpoint here in Phoenix can be in the single digits at times, makes these simple contraptions really look like genius.

Make sure that the water is getting pumped to all sections of the pad(s).

Make sure the system has a "bleed-off" or some sort of flushing system to keep the water fresh. Constantly recirculating water in an evap. gets pretty green, quick.

Make sure the motor is turning the squirrel cage without slipping the belt. There are also grease fittings, usually, on the axle for the fan.

Also keep in mind that because these numbers push air into your house, it also has to have an exhaust somewhere. Open the window farthest from the cooler a little. Some places have "upducts" which allow the warmest air to push open a louver in the ceiling and exhaust into the attic. Look for a covered grate with an easily removable slide/blocking plate.

Some systems, like mine, integrate regular a/c with a cooler, so they share the same ductwork. Many times, these systems will block the main ductwork of the house off from the subsystem that supplies fresh air from the cooler by means of a removable metal blockoff plate in the ductwork, or by a set of one-way louvers that operate automatically as you switch from cooler to a/c system (or, when you forget and leave it on during a cool night, on comes the heating system).

Some homes can toggle between the systems automatically, up to the point where a simple computer can measure the outdoor air temp/humidity (dew point result) and tell the house which system to use, then carrying out the process. Mine - - - not so much. heck, the evap. cooler ran off an extension cord (and it is mounted on the side of the house) for twelve years. Now it's wired up correctly with a high/low fan speed and the option of running the pump to humidify/cool or just the fan to provide outside air. Speaking of outside air, whole-house/ceiling mounted fans can do the same thing with suction, rather than pressure, just no real cooling properties.

I just have to be careful not to run the two systems at the same time, as mine are totally electrically discreet. I have forgotten - had the nighttime heat setting at 72 on the heat pump, then the evaporative cooler that was left on for the afternoon heat cools the house down too much after dark and they fight each other until you realize there's a little too much noise coming from the duct work and the air feels both cool and warm ... ?

Anyway, congrats on getting it up and running. Sure beats the heat when the conditions are right.

John B.