Triple values of exhaust gas

The combination of exhaust gas temperature (° C), exhaust gas mass flow (g / s, kg / s & kg / h) and minimum delivery pressure (Pa) are referred to as triple values of exhaust gas. These factors, including the chimney height, are necessary for the calculation of the chimney diameter and allow fireplaces from different manufacturers to be compared on the basis of their flow behaviour.

The exhaust gas temperature is used to calculate the pressure difference in the chimney. This must at least reach the minimum pressure required for the fireplace, so that the exhaust gases can be discharged and sufficient combustion air can flow into the fireplace. Through this process, the combustion is maintained. The unit for pressure is usually in Pascal (Pa).

During combustion process, the resulting flue gases mix with excess air and water vapor, which increase the weight of the exhaust gas.

The exhaust gas mass flow here indicates the resulting mass of this mixture per unit of time, which the respective heat generator produces and must be passed through the chimney into the open. This is stated either in grams per second (g/s) or in kilograms per hour (kg/h).