I get a negative impact result when calculation on just one flow even though this flow has positive impacts

Question

When I do a test calculation for just one Process in the PEF database I receive negative values. This occurs for various PEF Processes (materials) like "Alkyd resin dispersion (self-emulsified); technology mix; production mix, at plant; 50% in water"

When I inspect the impact values on the Process level they are positive as expected, so I am very surprised that they become inverted (negative) when I do a calculation.

Your help would be much appreciated.

Comments

I add the Flow as Input. In this case  "Urea formaldehyde resin".  I do "Direct calculation" of the Process.  It then shows the impact as negative values?
I find the "Urea formaldehyde resin" in the PEF database under Materials production/Organic chemicals/nan/Urea-formaldehyde resin.

Answer 1

Thank you for the further explanation - direct calculation makes a product system with autoconnect and calculates this directly, on the fly, therefore you should not use direct calculation for PEF and GaBi-like databases.