The answer to 'types of heat exchanger' is that there are several common types of heat exchangers used in HVAC systems. The most common are:
Tube and Shell Heat Exchangers - These feature a series of tubes through which one fluid flows, surrounded by a shell through which another fluid flows. This allows for efficient heat transfer between the two fluids.
Plate Heat Exchangers - These have a series of thin, corrugated metal plates with spaces between them. The two fluids flow through the alternating spaces, allowing for compact and efficient heat transfer.
Fin and Tube Heat Exchangers - These have a series of tubes with metal fins attached to the exterior. This increases the surface area for heat transfer between the tubes and the surrounding air.