Abstract:
Background and aims: Using water pump in residential buildings to provide the required water pressure is accompanied by noise pollution and the annoyance of residents. So, the purpose of this study is to reduce water pump noise pollution with designed acoustic curtains in a residential building of Qazvin city.

Methods: The mean sound pressure level was measured before and after control intervention around the sound source based on ISO 9612, using the sound level meter (Casella-Cell.450). The sound level meter was calibrated using a calibrator(Cell-110/2). The frequency analysis was done in 1.1 octave band and the weighting frequency of A. Acoustical features of acoustic curtains (thickness, material and dimensions)were determined on the base of required sound transmission loss in predominant frequency. The volumetric flow of air required to decrease the temperature inside the enclosure up to 40°C to maintain a reasonable air temperature for pump performance was calculated using the energy-mass conservation law. Temperature inside the enclosure was measured with a mercuric thermometer.

Result: The mean sound pressure level before and after control around the pump was measured 67 dBA and 46 dBA respectively. The required insertion loss in predominant frequency(2000 Hz) to accommodate noise limit in residential buildings was considered to be 26 dB and based on which acoustic curtain surface density was calculated between. The average sound pressure level measured after control(46dBA) with predicted sound pressure level by mathematical calculation after control(47dBA) was not significantly different. The volumetric flow rate required to maintain a temperature of 40°C inside the enclosure was calculated to be 1.2 cubic meters per minute. The temperature was measured inside the enclosure of 38° C.

Conclusion: Control of noise pollution using acoustic curtains with a lower cost and weight, higher installation speed and higher sealing can be considered as one of the proper methods for enclosing noise resources.
Keywords: Noise Pollution, Water pump, Acoustic curtains,Noise control