Hevacomp Netsys Ductwork Pressure Drop Calculation

Dear Hevacomp Technical Support Team,

We understand that Hevacomp Ductwork Pressure Drop Calculation based their calculation as described in section C of CIBSE Guide but recently noticed that it is in edition 2001. We already have updated data on CIBSE Guide C as per edition 2007. This will cause big problem to us as there is an updates on K values of duct fittings between two CIBSE Guide version. Do we have a way to load the updated K value (CIBSE Guide C 2007) into the software so we can recalculate and come up with more realistic output?  Is there a way to edit the K value in the data bank in Hevacomp? Can we edit manually the Kvalue of the autogenerated fittings in Hevacomp netsys?

We excerpt images from each version of CIBSE a K value of rectangular short bend duct to show a big discrepancy between two. Note that this is a sample only, other type of fittings have the same issue as well.

It seems that the K value is bigger in edition 2001 for hard bend and smaller K value for easy bend. This  will have a big impact on the pressure loss result.

As of the moment we want to clarify the below.

If we add a user defined fitting (to setup the K value as described in CIBSE Guide C 2007) to an autogenerated fittings (like elbow and tees), will this overide the pressure drop of existing fittings? or both will be included in the calculation?

This is something urgent/important so we appreciate your prompt responds on this matter.

Godspeed,