3. Provisions common to all ducts

DTU 24.1 distinguishes between external and internal flues.

• Fitness for purpose :

  • evacuate the products of combustion from all or only one of the fuels;

  • resist the chemical action of combustion products ;

  • provide the draught required to operate the connected heat generators;

  • withstand the temperature action of combustion products.

• Special conditions:

  • Multi-fuel pipes: the pipes must withstand a combustion product temperature of 350°C and a peak temperature of 450°C for one hour without damage;

  • special gas ducts: the ducts must withstand a combustion...