Condensing Boilers: Reusing Heat
Boilers that utilize water vapor that is produced during combustion and condense it into water are called condensing boilers. The condensed water exits the system through a drain. A condensing boiler is a high efficiency boiler because it uses the excess heat in the flue in order to pre-heat cold water that is beginning to enter the boiler. Condensing boilers can have up to 98 percent efficiency. Due to the high efficiency–and therefore environmentally friendly–nature of the condensing boiler, many countries require or encourage its citizens to use them. Often times governments offer a financial incentive to help with the costs.
Fairly simple to understand, boilers apply heat to water. The heated water boils and circulates through the boiler system as extremely hot water or steam. Boilers need to be in fireproofed areas that are well ventilated. They also need intakes for water and fuel.
Condensing boilers work similarly to conventional boilers. The main difference between the two is that water vapor heat escapes through the flue with a conventional boiler and the water vapor heat is reused rather than leaving the boiler system. Condensing boilers are found in a multitude of industries, applications and environments: offices, schools, residential units, factories and more. Condensing boilers can also be used to heat pools. Typically box-shaped and safely housed in casing made of cast iron, steel, stainless steel or copper, condensing boilers can be used for applications beyond general heating in manufacturing and industrial processes.
Designed for success, condensing boilers offer 30 percent higher efficiency than conventional boilers and emit far less carbon dioxide into the atmosphere. There are three kinds of condensing boilers: regular, combination and system. Regular boilers utilize a hot water cylinder to store water. Combination boilers do not use a hot water cylinder, but instead use multiple heat sources. System boilers have a hot water cylinder with all the boiler’s major components built right in.