Inconsistent desing parameters error message for chiller

2 posts / 0 new
Last post

I have been working on a model for a loop-to-loop heat pump system (to a
lake or well), and have been getting the following error message:

Heat-Exchanger: New HP Chiller 1 has

inconsistent design parameters:

QhxDesign SupFlow SupTi SupTo

-44451328. 3531. 88.1 63.0

DemFlow DemTi DemTo

2973. 63.1 93.0

The chiller design criteria is 31800000 cooling, with evap flow at 64 to 44
with 3169 gpm and condenser flow at 85 to 105 with 3743 gpm. The heat sink
for the condenser loop is intended to run from 75 F to 95 F at design

I am assuming that the negative energy value above indicates that the values
refer to the chiller in heating mode. Can anyone suggest the most like
causes for this error?


MaryAnne Mason

Maryanne Mason's picture
Joined: 2011-09-30
Reputation: 0


I realize I am asking for relative numbers, but I am unsure how much Demand Control Ventilation can actually save a building. I ran the DCV Up/Down scenario on a 150,000 sf office in Oregon, where the fans ran 24/7 (and the people weren't there at night). BTW, this was a VAV/VFD system.

My results show a 15% savings in cooling, a 64% savings in heating, and a 78% savings in fan.

Reasonable? Or am I "mis-simulating ??"

John R. Aulbach, PE, CEM

John Aulbach's picture
Joined: 2011-09-30
Reputation: 1