Air humidification system

An air humidification system comprising:

• a housing, an evaporator pad, a water delivery system with a water control valve, a drain system, an upstream temperature sensor, a downstream temperature sensor, and a controller;
• wherein said controller:
• monitors the temperature drop of an air flow across the evaporative pad;
• determines whether said temperature drop is increasing or decreasing;
• determines the maximum temperature drop thus far during a call for humidity;
• opens said valve when said temperature drop is decreasing and is less than or equal to a predetermined fraction of said maximum temperature drop thus far;
• and
• closes said valve when said temperature drop is increasing.

A method of controlling water delivery to an evaporative pad in an air humidifier comprising:

• during a call for humidity:
• monitoring the temperature drop of the air flow across said evaporative pad;
• determining whether said temperature drop is increasing or decreasing;
• determining the maximum temperature drop thus far during said call for humidity;
• opening a control valve which supplies water to said pad when said temperature drop is decreasing and is less than or equal to a predetermined fraction of said maximum temperature drop;
• and
• closing said control valve when said temperature drop is increasing.