APPLICATION OF ACOUSTICALLY TRANSPARENT PLENUM TO NOISE OF CROSS-FLOW FAN SYSTEM

摘要

In this study, acoustically transparent plenum is used to rate the noise of the wall mounting type air conditioner indoor unit. Selecting low noise fan and flow system, it has been general to measure the noise level at an operation point. Comparing with the method above, the method using an acoustically transparent plenum is advantageous because it gives noise data on PQ curve called specific noise. However, some errors are inevitable because this method is based on an assumption that the plenum has no influence on the aero-acoustic noise generated from the system and complicated procedure is also cause of uncertainty. In this study, a series of study related with the verification of this method was made. Acoustical transparency of the plenum was tested and possible errors that could occur during the test were discussed. By comparing the rating result of each method, the usefulness of the method using acoustically transparent plenum is discussed.