One simple way to do it is to attach a water pump (like the kind you’d use in a fish tank) to some copper tubing, then coil the copper tubing and install it inside the front grille of a fan. You’ll need to put the pump in a cooler full of cold water. This will work best with ice in the cooler, but even chilled water without ice in it should help cool the copper tubes and the air circulating around them.