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 5996-01-592-3011
NSN 5835-00-327-6192
NSN 5925-01-529-1895
NSN 6240-00-548-0209
NSN 5990-00-697-8883
NSN 6130-01-176-2727
NSN 5999-01-604-4498
NSN 4140-01-304-1597
NSN 6685-01-046-8459
NSN 5990-00-336-2054
NSN 5999-01-363-9399
NSN 4140-01-281-8832