ABSTRACT
A reheat coil is one whose job is to heat up air that has already been conditioned by some cooling process. The sizing of reheat capacities is a direct result of the load run by the mechanical designer. Electric heating coils are constructed of electric resistance heating elements, which are placed in the air stream. Step controllers are multistage temperature controllers or “sequencers,” requiring a control signal from a space temperature sensor/controller. A hot water or steam coil used in a reheat application will be equipped with a control valve. Proportional reheat control is more costly than two-position control, but the benefits reaped from going this route should in most cases outweigh the cost differential between the two methods of control.
