D1 Stack Height

Appropriate chimney heights for pollutant dispersion can be calculated in accordance with HMIP’s Technical Guidance Note D1 “Guidelines on Discharge Stack Heights for Polluting Emissions”.

The methodology takes into account a number of factors, including stack diameter, pollutant emission rates, emission temperature, efflux velocity and the effect of nearby buildings.   This simple, low cost method dates from 1993 but is still widely used and accepted by regulators and site operators and can be applied to single chimneys or groups of chimneys.

Alternatively, detailed dispersion modelling can be used to generate a more accurate stack height.  Although dispersion modelling is more expensive, it can be cost effective in cases where the D1 calculation results in excessively high stack heights that would be expensive to install.

To discuss this service, please contact Trevor Halliday on t.halliday@castingstechnology.com or call 07787500063.

Alternatively, Cti can also assess the dispersion of pollutants using the Environment Agency’s IPPC HI software and Guidance Note: Environmental Assessment and Approval of BAT.