What is BS EN 13384‑2 - thermal and fluid dynamic calculations for chimneys about?
BS EN 13384-2 is the first part of the EN 13384 multi-series that discusses thermal and fluid dynamic calculation methods for chimneys.
BS EN 13384-2 specifies methods for calculation of the thermal and fluid dynamic characteristics of chimneys serving more than one combustion appliance.
BS EN 13384-2 covers both the cases, either:
- Where the chimney is connected with more than one connecting flue pipe from individual or several appliances in a multi-inlet arrangement
- Where the chimney is connected with an individual connecting flue pipe connecting more than one appliance in a cascade arrangement
BS EN 13384-2 deals with chimneys operating under negative pressure conditions (there can be positive pressure conditions in the connecting flue pipe) and with chimneys operating under positive pressure conditions and is valid for chimneys serving combustion appliances for liquid, gaseous and solid fuels.
- Note: BS EN 13384-2 does not apply to:
- Chimneys with different thermal resistance or different cross-section in the various chimney
- segments. This part does not apply to calculate energy gain
- Chimneys with open fireplaces, for example, open fire chimneys or chimney inlets which are normally intended to operate open to the room
- Chimneys that serve different kinds of combustion appliances regarding natural draught, fan assisted, forced draught or combustion engine. Fan assisted appliances with draught diverter between the fan and the chimney are considered as natural draught appliances
- Chimneys with multiple inlets from more than 5 storeys. (This does not apply to balanced flue chimney.)
- Chimneys serving combustion appliances with open-air supply through ventilation openings or air ducts, which are not installed in the same air supply pressure region (for example, the same side of building)
For positive pressure chimneys, BS EN 13384-2 only applies if any combustion appliance which is out of action can be positively isolated to prevent flue gas backflow.
Who is BS EN 13384‑2 - thermal and fluid dynamic calculations for chimneys for?
BS EN 13384‑2 on thermal and fluid dynamic calculations for chimneys is useful for:
- Industries or factories with multi-inlet chimneys
- Chimney installers and maintenance personnel
Why should you use BS EN 13384‑2 - thermal and fluid dynamic calculations for chimneys? Negative air pressure in chimneys occurs when the air pressure inside the building is less than the air pressure outdoors. In such cases when you light up the furnaces or boilers beneath the chimney it may push the smoke back inside the building. These negative and positive pressure also affect the performance of the combustion source.
BS EN 13384-2 guides you through the process of calculating thermal and fluid dynamics in chimneys serving a single appliance. BS EN 13384-2 helps you understand the concept of airflow and its importance in chimney performance.
The calculation formulas and guidance given in BS EN 13384-2 enable you to install or build chimneys that are more resilient to airflow and air pressure and thereby enhance their build quality.
What’s changed since the last update?
BS EN 13384‑2:2015+A1:2019 supersedes EN 13384-2:2015. The main changes in BS EN 13384‑2:2015+A1:2019 compared to EN 13384-2:2015 are as follows.
- Mistakes in formulas have been corrected
- Characteristic values for combustion" appliances for solid fuel and for liquid fuels in Annex B have been adapted to actual data
- For the mixture of fuels a clarification about the rise of the dew point has been added;
- For non-concentric ducts the calculation of the mean temperature of the air supply has been amended
- The process for iteration for appliances with low impact of the pressure to the flue gas mass flow (e.g. CHP with combustion engine) has been simplified
