Server Heat Load Based CRAC Fan Controller Paired With Rear Door Heat Exchanger

Abstract

This paper discusses the preliminary design of a controller for the cooling air conditioning units (CRAC) fan speed based on server loads. The CRAC is paired with a rear door heat exchanger. The main purpose in implementing this controller is the reduce energy consumption and to have finer control in the provision of cooling within a data center. Tools that will be essential for developing this controller are CRACs with variable frequency drives (VFD), BCMS power monitoring, data archiving software (PI from OSISOFT) and MATLAB. For this experiment, the zone of interest in the data center consists of 10 racks of IBM Blade Centers with a maximum electrical load of approximately 24 kW each and a total of 3360 nodes. Results are compared with the conventional cooling method to quantify energy savings and corresponding chiller coefficient of performance (COP).