Negative values (amounts) of inputs and outputs flows

Question

Hi users and Moderator of openLCA,
I post again the questions on the negative values (amounts) of inputs and outputs flows given in the ready-made processes of databases (ELCD, ecoinvent, etc.).
There are elementary, product and waste flows with negative values for some process data sets of the above databases. When calculating the impacts of a product system which comprises flows with negative amounts, the LCIA results will be affected.
I can’t understand what the meaning of “negative amount (value)” of an inputs or outputs flow is .
So, my question are:
When and why a flow (nevertheless its type) has a negative amount in the process data set?
Can someone give me a link to resources where I would be able to find more information, as my question does not concern the openLCA, but the databases with which application works.
Thanks in advance.
Chris P

Answer 1

When and why a flow (nevertheless its type) has a negative amount in the process data set?

sure, I will try: because of system expansion, and / or because of ecoinvent moving a waste to the input side.
There should be plenty of resources for both available on the net.
Hth,
Andreas

Comments

Thanks Andreas,
I found info on http://www.ecoinvent.org/support/faqs/methodology-of-ecoinvent-3/why-is-the-reference-product-of-the-treatment-activities-negative.htm

Chris P