International. A global IT company has a 3 MWt chilled water system that serves its data centers and consists of three chillers and two dry air cooling units, with corresponding main and secondary pumps.
An examination of the facility, located in Ireland, indicated that the system was operating without effective sequencing and without properly automated control, and that the Free Cooling loop was also not optimally installed. The main challenge was to implement these improvements without compromising the availability and day-to-day operations of the European data center.
The solution: custom design and installation
Johnson Controls developed an integrated solution with the minimum cost following an agreement whereby the client would invest as long as the conditions of return on investment were met. The technical solution included the following elements:
▸ Making modifications to the pipes of the Free Cooling circuit using a live interconnection method (hot tapping) to use them as a pre-cooling mechanism and thus optimize the controls of the dry cooling circuit. The customer lamented that, prior to our performance, fluid temperatures increased considerably when the Free Cooling circuit was in operation.
▸ Installation of two-way shut-off valves in chiller circuits to enable effective sequencing, modification of controls and installation of additional sensors.
▸ Installation and optimization of variable speed drives in the main and secondary pumps to enable the control of the sequences.
▸ Installation of new secondary pumps to replace deteriorated components.
Advantages and results
From the outset, the company presented the customer with a clear business case that offered a guaranteed fixed-price solution with accurate estimates of energy savings.
This included:
▸ Return on investment in four years compared to the maximum five years established in the specifications
▸ The cost of replacing the secondary pumps was included in the business case, so the customer's maintenance budget was not affected, as the pumps had reached the end of their useful life
▸ 380,000 kWh of electricity savings per year
▸ 204 tons of carbon emissions less
