This type of heat exchanger uses "sandwiched" passages containing fins to increase the effectivity of the unit. The designs include crossflow and counterflow coupled with various fin configurations such as straight fins, offset fins and wavy fins.
Plate and fin heat exchangers are usually made of aluminium alloys which provide higher heat transfer efficiency. The material enables the system to operate at a lower temperature and reduce the weight of the equipment. Plate and fin heat exchangers are mostly used for low temperature services such as natural gas, helium and oxygen liquefaction plants, air separation plants and transport industries such as motor and aircraft engines. Advantages of plate and fin heat exchangers: 1. 	High heat transfer efficiency especially in gas treatment 2. 	Larger heat transfer area 3. 	Approximately 5 times lighter in weight than that of shell and tube heat exchanger 4. 	Able to withstand high pressure Disadvantages of plate and fin heat exchangers: 1. 	Might cause clogging as the pathways are very narrow 2. 	Difficult to clean the pathways 3. 	Aluminum alloys are susceptible to Mercury Liquid Embrittlement Failure