The problem is with the rounding increment being set to Custom / 0, not the
"None" selection. If you change the rounding increment to Custom / 1 or to 0
decimal places you will be able to select "None" as the unit suffix.
hth
jason
"mwwce" wrote in message news:6022642@discussion.autodesk.com...
> After searching in past posted topics, a way to remove the "CFM" from the
> air device tagged amount was to go to settings/project units/hvac/air
> flow - and then set "unit suffix" to none. Trying this in 2009 (unit
> symbol pulldown), I receive an "Invalid Input!" warning from Revit and am
> forced to use "CFM". Its not the end of the world, but it'd be nice to
> have the "CFM" out of the tag while maintaining the "air flow" parameter.