ANSI AHRI 640-2005 pdf download Performance Rating of Commercial and Industrial Humidifiers
3.1.1.3 Ultrasonic Atomizer. A piezoelectric transducer immersed in a reservoir of mineral free water. The transducer converts a high-frequency electronic signal into a high-frequency mechanical oscillation. The mechanical oscillation is directed at the surface of the water, where at very high frequencies it creates a fine mist.
3.1.2 Direct Injection Steam Humidifiers. A type of Humidifier intended for duct applications in which steam, water vapor under pressure and at high temperature, is dispersed directly into the air.
a. Steam Cup Type. Utilizes a cup and drain mounted beneath the duct. Steam is injected into the sides of a cup allowing most of the moisture of the steam to enter into the air while permitting the condensate to fall into the cup by gravity and into the steam trap.
b. Steam Separator Type. Utilizes an enclosed distribution pipe, a separating chamber, an integral control valve, and a drain to distribute steam into the air. Steam is injected directly into the enclosed distribution pipe providing reheat to the outgoing steam passing through the distributor pipe before being released into the air. The steam then enters the separating chamber which allows dry steam to pass through the control valve and into the distributor pipe while allowing condensate to fall by gravity into the drain. The moisture of the steam is reheated while in the distributor pipe before being dispersed into the air. c. Steam Panel Type. Utilizes an integral control valve, a header with multiple distributor pipes, and a drain. The control valve regulates the amount of steam that is injected into the header, which allows dry steam to pass into the distributor pipe(s) while allowing condensate to escape through the drain. The moisture of the steam in the distributor pipe(s) is dispersed into the air.