Kathiresan,

I don't think you can do a parametric run of a water economizer chiller in the way you describe. As I noted in my response to Tom a couple years ago, you'll need to define a *separate* water economizer chiller, condenser loop, and cooling tower *in addition to* the other chiller(s), loop(s), and cooling tower(s). This will probably be more successful if you generate a separate model to compare to your baseline rather than attempt it as a parametric run. Have a look at the equest/DOE new features manual at the section on ?water economizer chillers?.

If you continue to run into problems, I recommend posting your .inp and .pd2 files to the equest users list. For any given modeling problem, odds are there's at least one person on the list who's worked out a defensible/sensible method of handling the problem.

Good luck,

Steven