Bentley Hevacomp V8i v26 now includes the option to implement the BS EN 806-3:2006 standards for pipe sizing.
This applies to HWS and CWS systems in both Netsys and System Builder.
Loading units and flow rate calculation methods specified by BS EN 806-3 differ to that of the preceding BS 6700. Both of these standards are available in Hevacomp v8i v26.
The Pipes>Defaults menu now displays options for BS 6700 and BS EN 806-3, as in image below.
Existing projects from previous versions of Hevacomp will remain set to BS 6700. All new projects created in Hevacomp v26 will default to BS EN 806-3 automatically.
If changing the standards on your project, ensure you recalculate your system.
BS EN 806-3 uses both different loading units and a different flow rate calculation method to that of BS 6700.
Should you wish to specify a specific flow rate at your outlet rather than use these loading units, then you can instead enter a figure for Continuous flow, as below.
The effect of the new standards on flow rate results is best shown by example. Consider the following system:
Note that the pipe properties in the example above represent:
Looking at section one, for example, the key figures are:
The Design flow rate can then be obtained from Figure B.1, BS EN 806-3, which plots Total flow rate (x-axis, LU) vs Design flow rate (y-axis, l/s), alongside values for the highest single Loading unit. Below, the total flow rate is highlighted in yellow, and the highest single loading unit is highlighted in red:
The point of intersection between these two lines shows the corresponding Design flow rate on the y-axis, in this case 0.483 l/s.