Heat exchangers, in which heat is transferred from hot gases passing through the tubes to the cold water in the shell.
Fire tube designs are frequently applied in condensing boilers due to their multiple advantages: durability, ease of cleaning and maintenance, small footprint, lightweight construction, large heat transfer area and low pressure drops.
Tubes are dimpled, which provides a turbulent flow and increases the heat transfer area.
The tubes are spaced far apart, which makes it easy for any impurities to be removed with condensate and to access and clean the inside of the tubes during the maintenance process, if necessary.
Fire tube heat exchangers can handle large temperature differences between the hot and cold fluids.
Fire tube heat exchangers can be used to transfer heat between a wide range of fluids, including gases, liquids, and steam.
Fire tubes have a relatively small footprint at lower outputs for residential and light commercial applications.