By the type of coolant, the firebox is divided into furnaces with a water circuit (coolant - hot water) and with a heat circuit (coolant - hot air)
According to the material, the fireboxes are classified into made of steel or cast iron. Cast iron furnaces are heated well and give heat well, but unlike steel, they are not so much susceptible to deformation when temperature drops. If the cast -iron furnace is not exploited for a long time, then it is not as exposed to corrosion as other materials. On the walls of the fireplaces are also located additional cast -iron plates that increase the efficiency of heating.
