Retrotec USACE - Manual (Page 381)

Appendix J J5
to deliver the same amount of cooling. The chiller energy increased
from 332 kW to 452 kW, an increase of 120 kW. There was a savings
in cooling tower energy of approximately 40 kW, since we raised the
condenser water temperature setpoint, but the net effect on the system
was an increase of 80 kW, or approximately 21% more energy to pro-
vide the same level of cooling.
When the condenser water temperature was released back to LOBOS
■
operating controls, the effi ciency was returned to the previously
obtained levels.
This also shows that a facility can be designed with excellent cooling
■
equipment, but if it is operated and controlled in a “normal” manner,
the effi ciency can suffer in a rather dramatic fashion compared to the
potential effi ciency.
J.4 LOBOS Control Screens
Figure J3. Chiller Plant Tuning Graphic: simple, requires only four adjustments. Differential
pressure and chilled water supply temperature are adjusted when loads are increasing and
decreasing.