范围详细说明与nat一起使用的非循环型直接燃气工业空气加热器标准的试验和检验。，多功能显示器。以及混合气体、液化石油气和液化石油气-空气混合物。非循环型直接燃气工业空气加热器被称为加热器，“其目的是补偿建筑物的热损失。进入加热器的所有空气应直接从室外输送，加热器产生的燃烧产物被释放到正在加热的气流中。”

ScopeDetails test and examination of criteria for direct gas-fired industrial air heaters of the non-recirculating type, for use with nat., mfd. and mixed gases, LP gases, and LP gas-air mixtures. A direct gas-fired industrial air heater of the non-recirculating type is described as a heater "whose purpose is to offset building heat loss. All 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."