NOISE ELIMINATION CALCULATING DEVICE FOR AIR-CONDITIONING DUCT SYSTEM

摘要

PURPOSE: To predict a noise in an optional place between an air blower and a duct end part with high precision even if a secondary air flow sound is generated halfway in the duct. CONSTITUTION: The noise power level up to the duct end part is calculated from the noise power level generated by the air blower through addition and subtraction based upon the air flow sound power level and reduced sound volume power level of a duct element, and then the duct element which increases in 1st noise power level halfway in the duct is detected from the 1st noise power level calculated from the upstream side; and the duct element is regarded as a noise source and the reduced sound volume power levels of respective duct elements are calculated from the noise power level in the place in order toward the upstream side of the duct, thereby calculating a secondary noise power level. Then the 1st noise power level calculated from the upstream side and the 2nd noise power level calculated from the downstream side are added to find the noise power level of the air-conditioning duct system.