P&K KFA (VDI 3781 part 4)

Preliminary Note

Scope

This standard serves to determine the minimum height of the outlets of exhaust gas discharge systems that are used to discharge emissions from combustion systems, from installations that release organic solvents (e.g. installations not requiring a permit within the scope of 31. BImSchV (31st German Federal Immission Control Ordinance)) and from other pollutant-emitting installations.

From an air pollution control perspective, there is no difference in principle between the discharge conditions for exhaust gas from small and medium combustion systems in accordance with 1. BImSchV, for vapours of organic solvents from installations requiring a permit in accordance with 4. BImSchV under conditions of low emission mass flows, and for installations not requiring a permit. The provisions of VDI 2280 have, therefore, been incorporated in VDI 3781 Part 4.

The minimum height determined in accordance with this standard meets the requirements for undisturbed removal of exhaust gas with the free airflow and for adequate dilution of the exhaust gas, in order to prevent harmful environmental effects that are avoidable with the best available techniques, and minimize those that are unavoidable (cf. BImSchG (German Federal Immission Control Act)).

This standard does not apply to the chimneys of the following heating appliances:

• gas appliances 1) with a nominal heat output up to 400 kW, operated with gases from the public gas grid or liquid gas
• condensing oil boilers with a nominal heat output up to 400 kW, using oil type EL low-sulphur in accordance with DIN 51603-1
• forced-draught oil boilers with a nominal heat output up to 70 kW, using oil type EL low-sulphur in accordance with DIN 51603-1

Reference: VDI / Source, Beuth / Guideline