Active noise control rack enclosures

A system to control fan noise in a computer server room, comprising:

• one or more transducers coupled to one or more exterior walls of a plurality of system racks, the coupling configured to enable the one or more exterior walls to function as diaphragms for the one or more transducers;
• one or more active noise control units, wherein the one or more active noise control units send control signals to the one or more transducers to emit a transducer acoustic wave;
• and
• a microphone installed near a location in the computer server room where cooling fan noise needs to be controlled, wherein the microphone collects fan noise signals emitted from running fans on the plurality of system racks in the computer server room and send the collected fan noise signals to the one or more active noise control units to allow the frequency and intensity of the transducer acoustic wave to be substantially equal to a frequency and an intensity of the fan noise and at about 180 degrees out of phase with the fan noise to reduce or to eliminate the fan noise;
• wherein the one or more active noise control units analyze the collected fan noise signals sent by the microphone to determine the fan noise phase, frequency and intensity;
• wherein each of the one or more transducers comprises a fan speed detector that detects which fan on the system rack is running and at what speed, a room sound detector to detects the sound signals received by the microphone, and a transducer controller to issue control signals to the one or more transducers;
• wherein the transducer controller comprises a component location sensor, a transducer location identifier, an intensity setting unit, and a phase and frequency setting unit, wherein the component location sensor communicates the locations and status of components on the system rack to a transducer location identifier, the transducer location identifier selects which transducers need to be activated based on the locations and status of components and communicates which transducers have been selected to the intensity setting unit, and the phase and frequency setting unit, the intensity setting unit, and the phase and frequency setting unit receive fan noise signals from the microphone and which transducers have been selected from the transducer location identifier, send controlling signals to the selected transducers to emit acoustic waves.

A system for reducing fan noise, the system comprising:

• a system rack, the system rack including a plurality of computer systems and a plurality of fans for cooling the computer systems;
• a plurality of transducers coupled to one or more exterior walls of the system rack so as to enable the one or more exterior walls to function as diaphragms for the plurality of transducers;
• a transducer controller for providing control signals to selected transducers to emit transducer acoustic waves to reduce or eliminate fan noise produced by the plurality of fans, the transducer controller including,
• a component location sensor for determining the location and status of the computer systems and fans on the system rack,
• a transducer location identifier for determining the selected transducers based on the location and status of the computer systems and fans, the selected transducers being one or more of the plurality of transducers which are to be activated to emit canceling acoustic waves,
• a phase and frequency setting unit for determining phases and frequencies of the transducer acoustic waves emitted by the selected transducers;
• and
• an intensity setting unit for determining intensities of the transducer acoustic waves emitted by the selected transducers.