One of the main factors of scale in building installations is the presence of calcium carbonate in water, because the solubility of this compound in water is very low and if the conditions are right, it will precipitate quickly. One of the parts that provides these conditions is the surfaces in contact with water in heat exchangers in domestic gas-fired boilers (heat packages).

There are various types of heat exchangers in the industry, examples of which include: double-tube, plate, spiral tube and shell-and-tube heat exchangers, each of which has its own working method. Also, each heat exchanger has its own advantages and disadvantages.