Case Study: UC Davis Medical Center – COVID Testing Laboratory
Problem:
The three existing 55.0-ton air cooled chillers were originally designed to provide 70°F interior temperature throughout the main lab 24/7. Due to the equipment age and that fact that they are air cooled, these chillers no longer have the ability to maintain chilled water loop temperature when the ambient temperature exceeds 90⁰F. Additionally, the fittings connecting the chilled water piping that runs from the equipment pad into the building and under the roofline prior to penetrating the roof to each air handler are leaking, causing subsequent water damage throughout the entire facility.
Challenges:
New replacement chillers had to fit precisely into the existing equipment pad, utilize the existing power feeds and operate with significantly reduced decibels than that of the current equipment (running at 98DB). In addition, 380 feet of 6-inch chilled water piping also had to be relocated along the rooftop and tie into the existing mainlines below, with minimal down time. All this, and a required 30% redundancy on 90⁰F plus ambient days.
Solution:
Chillermen, a division AirCom Mechanical, Inc., custom designed and manufactured three 72-ton evaporative condensing chiller skids using the Pulse-Pure water treatment system, which significantly reduces the environmental impacts associated with the production, handling, and storage of chemicals. Prior to the completion of Chiller #1, AirCom began the installation of 380 feet of chilled water piping on the roof. The following week, the 6-inch main waterlines were connected to the rooftop equipment and chilled water mains below. Once the production of the new chillers was completed in our Milpitas location, AirCom
delivered and installed one chiller skid per week to UC Davis in Sacramento. This schedule eliminated any down time between replacements. The coordination between both ACM divisions and UC Davis facilities resulted in zero temperature related issues within the lab.
Outcomes and Benefits:
• 30% reduction in energy usage
• 20DB quieter over the previous air-cooled system
• Chemical free water treatment system
• Two chillers are maintaining 70°F lab temperature on 110°days, with no capacity loss
• System can produce 39°F water, regardless of the ambient temperature
• Chillermen equipment warranty 3 years parts and labor, regardless of run time
