Hot water coils are a type of heat exchanger often called hydronic coils that use hot water from a boiler to heat or remove moisture from the air. The air moves through the fins of the coil which is hot from water flowing through the tubes.
This again happens because air heaters deplete the quantity of moisture present in the air and cause the air to become dry.
The first thing to remember about coils and counter-flow is that chilled water coils are always built to be piped in counter-flow. This means that the air flows in the opposite direction as the water. For example, with counter-flow, the air flows through rows 1-8, while the water runs through rows 8-1. A coil is a heating element attached to the heating unit itself. The heater generates an electric current flowing into the coil, which transfers the electric energy into heat energy. It may be directly immersed in the medium to heat it or radiate heat through an open space.
