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SINK and SOURCE

Here is the description of SINK and SOURCE from the IfcFlowDirectionEnum
SOURCE: A flow source, where a substance flows out of the connection.
SINK: A flow sink, where a substance flows into the connection.

But in the following picture (1), (2a), (2b) and (3) a substance would flow out of the connection (depending from which side you see it):

SINK_OR_SOURCE_Bock

Is (1) and (2b) a SOURCE and (2a) and (3) a SINK?

1 Like

IMO - vice versa. The naming is a bit confusing. I would say SINK=IN and SOURCE=OUT. The documentation should be:

  • SOURCE: A flow source, where a substance flows out of the element.
  • SINK: A flow sink, where a substance flows into the element.

@TLiebich, do you remember the logic for this one?

@hannu.lahtela is right - source is supplying - so OUT, and sink is receiving - so IN

as written in the spec: “SOURCE: A flow source, where a substance flows OUT of the connection.
SINK: A flow sink, where a substance flows INto the connection”

actually the spec in my view is correct (but maybe terminology-wise confusing)

  • SOURCE: A flow source, where a substance flows OUT of the connection. – as in (2a) the flow is moving out of the connection point (the port) of the element
  • SINK: A flow sink, where a substance flows IN to the connection. – as in (2b) the flow is moving into the connection point (the port) of the element

Thanks for clarification @TLiebich, but I also agree with @hannu.lahtela to add a hint in the documentation, to what the port is relatet (element or port-connection), e.g.:

SOURCE: A flow source, where a substance flows out of the connection / element.
SINK: A flow sink, where a substance flows into the connection / element.

As a picture:

SINK_OR_SOURCE_Bock_solved