Hot and humid weather is heating up (number 2) and add moisture by spraying water at the set heating and evaporation is water vapor to the air temperature, steaming is used and relative humidity equal to that set.
And moist air is heated up by the heat (No. 2) and increase humidity by spraying water heater, and water vapor. So that air temperature and humidity of the steam setting.
The weather is hot and humid heat up by (the number 2) system and increasing the humidity by spraying water heating and evaporating a series of steam. To keep the air steam with temperature and relative humidity were set up.