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 7035-01-584-6219
NSN 5990-01-243-4233
NSN 5930-00-467-6808
NSN 2925-01-055-7607
NSN 5965-00-822-3284
NSN 6130-00-728-3497
NSN 5930-01-106-0771
NSN 5990-00-665-4105
NSN 6150-01-634-0575
NSN 6110-00-015-7688
NSN 6130-00-796-8760
NSN 6150-00-625-1349