The gross calorific value is the energy (in KJ/kg) which is emitted from complete burning.

In heating engineering, the gross calorific value includes the net calorific value (Hu) plus the energy released through condensation of the steam produced (the condensation heat).

In short, a condensing boiler works like a kettle, although the difference in technologies is enormous between the two devices. The following illustration shows clearly and briefly the functionality.

The condensing boiler is a heating system which uses the waste heat of the exhaust gases of your heating system and thereby contributes to the heating of the required hot water. The system works in a way comparable to a turbocharger in a car. While the turbocharger is driven by the exhaust gases of the vehicle, the condensing boiler system uses a water cooler positioned around the exhaust system of the heater. The water in the cooler is heated and channelled to the warm water system of the heater. This reduces the exhaust gas temperature to a fraction of the original value.

• Less energy is required.

• The energy is used in a highly efficient manner.

• The reduction of exhaust heat protects the environment.