The ventilation heater will be type ii per mil-h-16235, which requires nonmagntic construction, non magnetic material, tube has 60 fins per ft.
A heat transferring unit utilizing a separate source of steam or hot water as the heat transfer medium. It consists of finned parallel tubes joined together by a header or headers and is designed for installation in the ducts of a forced air circulating system. It may be provided with a flanged outer casing to facilitate mounting of the unit in planned or existing duct work. Circulation of the heated air is achieved by use of a blower or fan not integral with the heating unit.
Classification: Air heaters and hot air distributors, not electrically heated, incorporating a motor-driven fan or blower, and parts thereof, of iron or steel
NSN 5990-01-382-5364
NSN 5990-01-544-4360
NSN 5960-01-250-1095
NSN 5975-00-035-6524
NSN 2925-01-338-7126
NSN 5998-01-562-9490
NSN 5975-00-016-9774
NSN 5935-01-243-1672
NSN 5999-00-420-4268
NSN 4140-00-694-1936
NSN 5915-01-480-9755
NSN 6150-01-500-2536