Any listing in this product directory or other related materials, where “NRTL” appears next to the product name was tested and is listed by ARL as an NRTL, consistent with the requirements of the NRTL Directive.  Other products are listed solely by ARL under its accreditation to ISO 17025 and ISO 17026.


The products listed here are fixed electric duct heaters, and remote control assemblies for such equipment, rated at 600 volts or less and are intended to be employed in ordinary locations in accordance with the National Electrical Code, ANSI/NFPA 70.

A duct heater is a self-contained heater designed to be installed in the field in the air stream of a ducted system, external to the air moving unit.  It is designed to be installed in a duct where an adequate flow of air from a separate, interlocked fan or blower system is provided.  Such a heater may be located in the main supply duct of an air heating system, or in one of the branch ducts.  Two or more duct heaters may be installed in a group (in proximity to one another in the duct) if testing indicated acceptable results when the heaters were installed in accordance with the (manufacturer)’s instructions.  Some duct heaters have been investigated for installations less than four feet downstream from the air moving device (close coupled application), and have been approved and listed for use with specific HVAC equipment.

A duct heater intended to be employed in conjunction with another source of heat has been judged on the basis of its compliance with the requirements of the standard, and further examination and tests to determine whether or not the combination was acceptable.

A duct heater intended for use in a hazardous location has been judged on the basis of its compliance with the requirements of the standard, together with the requirements for hazardous location equipment included in other applicable standards.

The requirements for this category apply to relays and other auxiliary control devices that may be provided as part of a duct heater to make it usable with other heating or cooling equipment, and are intended to take into account the effects of operating the duct heater in conjunction with or in proximity to such equipment.

Requirements for this category do not cover fan coil units, central heating furnaces, panel or cable type radiant heating equipment, electric boilers, baseboard heaters, air heaters, nor any other electric heating equipment or appliances which are covered in or as a part of separate, individual requirements.

Each product is marked with the name or trademark of the (manufacturer) or private labeler, a distinctive style, type, model or catalog designation, date code, place of manufacture (if produced at more than one factory), voltage or voltage range, frequency in hertz, number of phases, heater input in amperes, volt-amperes, or watts, range or maximum external static pressure, the minimum spacing to combustible surfaces if greater than zero, and other hazard and warning markings as required for individual products.

These products comply with ARL requirements which include pertinent sections of Standard for Safety, ANSI/UL 1996, Duct Heaters. Duct heaters designed to be connected to air duct systems are intended for installation in accordance with the Standard for Air Conditioning and Ventilating Systems, NFPA 90A, and the Standard for Warm Air Heating and Air Conditioning Systems, NFPA 90B.

A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements of the standard, and that involve a risk of fire, electric shock, or injury to persons, have been evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of the standard.  A product whose features, characteristics, components, materials, or systems conflict with specific provisions of the standard have been judged to be in non-compliance with the standard.

Only products which properly bear the ARL Listing Mark (Label) are considered Listed by ARL.


Delisted products appear with a double strike through and “DELISTED” after the report number.
Deleted/revised models for listed products appear with a single strike through.



Listed Product Directory (revised 01.13.15)