Preface

The standards set forth herein apply to the fourth edition of the Standard for Recirculating Direct Gas-Fired Industrial Air Heaters, ANSI Z83.18-2004 and ANSI Z83.18a-2005 and supersede corresponding standards therein. Following their preparation by the supervising Technical Advisory Group, they were accepted by the American National Standards Institute (ANSI), and subsequently approved.

NOTE: Changes, other than editorial, are denoted by a vertical line in the margin.

Scope

Details test and examination criteria for direct gas-fired industrial air heaters of the Recirculating type, for use with natural, manufactured and mixed gases, liquefied petroleum gases, and LP gas-air mixtures. A direct gas-fired industrial air heater of the Recirculating type is described in the standard as a heater whose purpose is to offset building heat loss. Ventilation air to the heater shall be ducted directly from outdoors and the products of combustion generated by the heater are released into the air stream being heated. Inside air may be introduced before or after the combustion zone.