Lag while working on HVAC system?

[Alexassyia]

I am working on creating a HVAC system for an office building and everytime I edit anything about the system (add duct, add fitting, delete something, change length) it takes at least 10 to 30 seconds per command. The computer has plenty of memory as it is only using 6 out of 15 GB. I think it may be caused by revit running calculations each time I edit something because if I draw a new piece of duct not connect to the main large HVAC system there is no lag for that segment but as soon as I connect it to the large system the lag is back. Is there a way to turn off the calculations that revit is doing?

Other details-

I have separated segments of the system on worksets and have turned them off when not using them but this does not fix the problem.

When I do anything with the system Revit says regenerating in the bottom left corner with a loading bar.

Your help would be greatly appreciated

Thanks

[julianjameson8403]

In the Type Properties of the Duct/Pipe Systems, there is a parameter called Calculations with the option to select All/Flow Only/None.

Try that and see if it helps

[Alexassyia]

I just tried changing the calculations to none but no luck... i cant notice any speed up. It seems like Revit wants to regenarate the whole system each time a change is made.