Usage Units (Potable Water)

Explains the concept of Usage units in the pipe network calculation for potable water.

To lower simultaneities and thereby get smaller pipe nominal diameters, usage units have been introduced along with DIN1988-300. The creation of usage units has to be coordinated with the building owner and has to be documented.

A usage unit is a sanitary room with at most two consumers. This assumes that maximum two tapping points might be used at the same time. Some consumers are excluded a priori and are not considered for the peak flow rate, since it is assumed that they will not be used simultaneously because only one person uses them. These are: an additional washstand (the washstand with the larger flow rate will be considered for calculation), a shower in addition to a bathtub, a bidet, a urinal or discharge valves.

The program sets automatically, if a consumer is to be considered for peak flow rate. Furthermore, you can choose individually for each discharge valve whether it shall be considered for the peak flow rate. This setting appears in the printout Usage unit and in the calculation dialog box in the overview of the flow paths in the column Consider peak flow rate.

In the Settings you may temporarily exclude predefined usage units from the calculation by deactivating the checkbox Consider Usage Units. Thus you can more easily compare the calculations results with and without consideration of usage units.

If you do not calculate according to DIN 1988-300 or SP30.13330.2016, you cannot assign usage units.