Hertz:
Turnkey Replacement of Chiller Units

The cooling system in Hertz facility is on call every day, resulting in total possible run hours per year of a little over 3,562 hours, however cooling demand of the HERTZ facility was assessed across a range of ambient conditions.

Sirus used a full-time-equivalent (FTE) hours system to express the chiller load for the selected conditions.

A base load figure of 800 FTE hours was selected as the cooling load for a ‘cool’ year. This equates to an average duty factor of 0.16. A load factor of 16% for much of the year is quite plausible considering that the Hertz facility is densely occupied, has a lot of IT gear and needs to be kept cool for worker comfort, even if ambient temperatures are low.

The Solution

Sirus replaced the old R22 chillers with new environmentally friendlier HITACHI Samurai Chillers (which mount standard semi-hermetic screw compressors), with equivalent performances and much better energy efficiency.

Hitachi is a leading manufacturer of chiller equipment using the energy efficient screw compressor. Hitachi’s cost-effectiveness, high levels of reliability and efficient operation have established them firmly in the Irish marketplace.

This project involved:

• Supply, Installation and Commissioning of two 1000 KW each Air Cooled Chillers,
• Upgrade of the primary pump set
• Simple Payback Analysis,
• Life Cycle Cost Analysis,
• Recovering and disposal of old R22 units,
• Installation of new pump-sets, pipework and electrical components.

The Result

The new chiller models provide modular, individual refrigeration and hydraulic circuits utilizing low noise and vibration, modulating compressor technology and high-efficiency plate heat exchangers, optimized for use with ozone-friendly refrigerants R407c.

The units provide close leaving water temperature control by means of state of the art microprocessors, which also offer fault-finding analysis and indication.

The new units were individually craned into position and installed over two weeks, without any impact or downtime of the chilled water system.

Throughout the project, Sirus ensured that all the works, right up to final commissioning, were carried out swiftly and with little or no disruption to HERTZ’s operations.