Duct reheat coils are used with hot water or steam for general heating applications. They are relatively easy to install.
There are usually upstream coils that regulate the leaving air temperature to a design intermediate level. The duct coil takes the air from that intermediate level to its final desired temperature.
As the name implies, these coils are generally designed to be installed into ducts. These coils may be installed in the ceilings of office buildings, schools, and more.