A heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another Anohter heater is a self-contained device for heating an enclosed area. heaters are usually portable or wall-mounted, and should be an electric heater in most cases, because natural gas or propane heating in an enclosed area is very dangerous without proper specialized ventilation systems.the heating of fluids which contain solids and thus have a tendency to foul the inside of the heat exchanger. The low pressure drop gives the SHE its ability to handle fouling more easily. The SHE uses a "self cleaning" mechanism, whereby fouled surfaces cause a localized increase in fluid velocity. type of heat exchanger uses an intermediate fluid or solid store to hold heat, which is then moved to the other side of the heat exchanger to be released. heat exchangers are usually made of aluminium alloys which provide higher heat transfer efficiency.Heat exchanger with a gas passing upwards through a shower of fluid.