Waste gases are created during industrial production and in particular during combustion processes. In order to minimise damaging effects on the environment, the gases must be expelled via chimneys in such a way that they can be freely dissipated by air currents. Where building structures are complex, and influence the free passage of air, or where exhaust gases have a strong odour, determining the correct height of chimneys can be a considerable challenge. We from the environment division of TÜV NORD will look for solutions for your particular situation and will calculate the chimney height you need.
Why must waste gases be dissipated with "free air currents"?
A central aspect when planning chimneys is undisturbed dissipation of the waste gases with the free air currents.
Neighbouring buildings and also trees must be taken into consideration here, as when buildings are subject to air currents approaching on the side facing away from the wind (lee side), a recirculation zone (i.e. air turbulence) occurs. If the waste gas plume or parts of it enter this zone, increased concentrations of hazardous substances can occur in the area of openings in the building itself (doors, windows, air vents) or in the neighbourhood.
In order to prevent this, a chimney must project clearly above this recirculation zone.
What rules apply?
Plants which do not require official approval
The Ordinance on Small Firing Installations (1.BImSchV) applies for plants which do not require official approval. In addition, depending on the individual application, various VDI guidelines can be used to determine the necessary chimney height. If the waste gases have a strong odour, the necessary dissipation height is calculated according to the Federal Odour Immission Guideline (Geruchsimmissions-Richtinie - GIRL).
Plants which require official approval
The chimney height calculation must generally be carried out according to the TA Luft (Technical Instructions on Air Quality Control) in the case of plants which require official approval according to 4. BImSchV (Ordinance on Installations Requiring a Permit). In the calculation, we determine both the emission-related and a vicinity-related chimney height. The larger of these two values is decisive as regards the necessary height.
For these plants also, the necessary dissipation height is determined according to the GIRL guideline in the case of waste gases with strong odour.
What services do we offer?
- First of all we decide what calculation rules and regulations have to be used.
- We determine the required input data for determination of the chimney height.
- We calculate the chimney height that is required in order to allow the waste gases to dissipate freely and to prevent too high a concentrations of hazardous substances nearby neighbouring buildings.
- We calculate the emission-related chimney height using the formulae on which the nomogram of the TA Luft is based.
- We determine the necessary dissipation height in special cases (e.g. in the case of waste gases with strong odour, complex building structures and configurations, consideration of existing chimneys and possible overlapping of waste gas plumes.
- We document the results of our evaluation in a report.
What is special about us?
We have been active in the area of chimney height calculation for more than 30 years and also have experience of special or unusual applications and circumstances. This also includes calculation of chimney height in the case of waste gases with a strong odour. In order to determine the chimney height that is necessary based on emission of hazardous substances, we make use of the formulae on which the nomogram of TA Luft is based.
Our operations are based on a quality management system that is certified according to ISO 9001:2000 and EN 17025.
Our experts will be pleased to answer individual questions at any time. Simply click on the contact box at the top right and send us an email.