Using ongoing data collection from chiller operation in a hospital central plant, ETC Group’s energy efficiency engineers were able to identify a chiller’s rapidly deteriorating efficiency and have it repaired within a week. In addition to the energy and cost savings, the hospital avoided a potential chiller failure leading into the summer.
Figure 1 – ClimaCheck Dashboard Showing Degradation
We actively monitor multiple hospital central plants within the Southwest region of the United States. In May, energy efficiency engineers observed one hospital chiller plant operating at 65% capacity. One chiller began consuming significantly more energy than its “sister” chiller over a short period of time. The chiller efficiency degraded by nearly 30% within a span of only three days.
Figure 2 – Evaporator and Chiller Efficiency
Upon deeper analysis of the other key performance indicators, energy efficiency engineers identified the chiller was very likely low on refrigerant. Evaporator saturation temperature plummeted below 30°F, evaporator approach temperature exceeded 15°F, discharge superheat increased above 25°F, and suction superheat surged to 12°F. These changes, along with the increase in power consumption, occurred so quickly that we knew this was a serious problem. We immediately alerted the owner to address this matter.
Figure 3 – Evaporator Saturation and Approach Temperatures
We coordinated efforts with the local hospital staff and mechanical contractor to investigate onsite further. They found a failed O-Ring seal that was leaking refrigerant. Five hundred pounds of refrigerant had been lost that, if not replenished, would have rendered the chiller unable to operate moving into the hottest months of summer.
“If we didn’t catch this O-ring failure and fix it quickly we would have been in real trouble… We’re thrilled to have the ETC Group’s energy efficiency engineering team supporting our plant operations.”
Chiller performance degradation is not desirable for any building owner. Chiller failure during the cooling season is far more than just an energy penalty. A facility evacuation is likely to cost significant amount of lost revenue and damaged reputation. ETC Group is proud to be partnered with such a large hospital chain that trusts our engineering expertise and ongoing analytics to help them identify and correct problematic equipment and degraded system performance.