Also known as "non-freeze", steam distributing coils are a different coil than standard steam because they are built with a tube within a tube construction. The steam on the inner tube keeps the condensate in the outer tube from freezing. The purpose of the original coil design was to distribute the steam evenly along the length of the coil and to eliminate and dead spots on the coil. A byproduct of this coil was also found. The coils didn’t freeze nearly as easily as the standard steam coil, so the coils became known as “non-freeze”, which is mostly correct, but not entirely. Any coil can freeze under the right conditions. But, this design is what needs to be used when the entering air is under 40F degrees. Steam distributing coils can be manufactured in 5/8” OD w/ 3/8” inner tube or 1” OD w/ 5/8” inner tube. Carrier, Trane, McQuay, York/JCI, Heatcraft are all manufacturers that we can easily duplicate often at a fraction of the cost of a new coil from the OEM and twice as fast.