CSA ANSI Z83.4a-2004/CSA 3.7a-2004

Details 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.