A double pipe heat exchanger is a type of heat exchanger that can be used to reduce the energy consumption of boilers. Double pipe heat exchangers are made up of two parallel sets of pipes that are connected at the base. The hot water passes through the first set of pipes, and the cold water passes through the second set of pipes. This arrangement allows the heat from the hot water to be transferred to the cold water, reducing the energy required to boil water. Read more from the blog.