How well do Outdoor Air Coolers cool and reduce the temperature?

The drop in temperature depends on  various factors i.e. Air Temperature, % Relative Humidity Level, Room  Size, Degree of Insulation & Cross Ventilation. The temperature of  air coming out of an evaporative air cooler depends on the temperature  and the humidity of the air going in. The constant movement of the air  created by the blower – the cooling breeze it creates, makes the  occupants of a room feel 4 to 6 degrees cooler than the actual  temperature.Evaporative air coolers works best in the hottest time of  the day. As the temperature outside increases as the sun climbs, the  humidity normally drops. In the early morning, for example, the  temperature may be 70 degrees, with a relative humidity of 60 percent.  By mid-afternoon, when the temperature has climbed to 90 degrees, the  humidity may well have dropped to 30 percent – conditions that make  evaporative cooling work more effectively.