Preface:

This is the harmonized CSA Group and UL Standard for Humidifiers. It is the fifth edition of CSA C22.2 No. 104, and the sixth edition of UL 998. This edition of CSA C22.2 No. 104 supersedes the previous edition(s) published on April 25, 2011. This edition of UL 998 supersedes the previous edition(s) published on April 25, 2011.

Scope:

1.1
These requirements cover humidifiers rated 600 V or less, and intended to be used in accordance with the National Electrical Code (NEC), ANSI/NFPA 70, and the rules of CSA C22.1, Canadian Electrical Code (CEC), Part I.

1.2
These requirements cover humidifiers intended for residential and commercial use. This includes humidifiers of the centrifugal atomizing type, evaporative-media type, water-injection type, steam type, and the like. The humidifiers are intended for installation in a room, mounted on a wall or a ceiling, or for duct or plenum mounting.

1.3
These requirements apply to equipment that includes an electric heating element to heat air or water, or both.

1.4
These requirements do not apply to evaporative coolers that are also intended to be used for cooling.

1.5
These requirements do not apply to portable, electrode-type products, such as vaporizers, which are covered by UL 499 and CAN/CSA-C22.2 No. 64.11.