Heating, Ventilating & Air-Conditioning (HVAC)

The data suite is serviced by 5 x 60kW Liebert-Hiross down flow air conditioning units that pressurise raised floor areas. Conditioned air rises up through cut outs under the racks and through floor grills in the circulation routes.

Air is re-circulated at high level back to the down flow units. The down flow units are equipped with chilled water coils and supply fans. The cooling capacity is modulated by way of 2-port valves on the chilled water pipe work controlling the return air temperature. To assure reliability from a power standpoint, units are alternately fed from separate switchgear locations.

The chilled water is generated by 5 x. 500kW air cooled York screw chillers which are provided on an N+1 basis. The N+1 criteria ensures that redundancy is created by having one more chiller than is required for the total maximum load. Chilled water is distributed around the data suite via a flow and return ring main system that is fed by diverse routings. This ensures that should any section of pipe work fail, that section can be isolated and the flow maintained to all other parts of the installation. The chilled water pumps are provided on an N+1 basis and are fed from a dual busbar control panel, which in turn has dual feeds. The ingress of pollutants and contaminants to the data halls is controlled by pressurising the data halls by roof mounted air handling units. These air handling units are equipped with ultrasonic humidifiers to control the data halls Relative Humidity level.

The chilled water piping under the raised floor is monitored by a leak detection system. Any leak will activate this system and will be located by control panel graphics. A leak occurring directly under one of the down flow units will cause that unit to shut down to isolate the leak.