sound

A research project is designed to evaluate different aspects affecting human comfort in an architectural space. One of the basic parts of the research project is the evaluation of the auditory, visual and thermal comfort. A university library in Istanbul is selected as the subject of the research. The library building, which has unusual settlement and design peculiarities, is an interesting case from acoustical view point as well, because of the closeness to a heavy traffic road and architectural properties.

The aim of this paper is to explain the results of a research project run in Yildiz Technical University which focuses on the optimum building envelope design for visual, thermal and acoustical comfort conditions in the offices placed in Istanbul city center. In this project, the building envelope alternatives are examined in terms of light, heat and sound considering the materials used mostly in Turkey.

The problem of the hygienic state of air-conditioning installations in many countries is still treated with limited attention and, in general, this issue is disregarded both when systems are designed and when the maintenance of already operating system is performed. In order to highlight problems resulting from contamination of the installation, microbiological assessment of air conditioning systems in a hospital was carried out. The measurements particularly pointed to increased microbiological contamination of air and dust deposited in the system just downstream of the sound attenuators.

The sound intensity technique and reverberant sound excitation have been used for the measurement of sound transmission loss through narrow slits in rigid walls. As predicted by theory, the dimensions of the apertures determine the magnitudes andresonant frequencies of the sound transmission loss curves. It should thus be possible in principle to size air leakage cracksusing the technique described in this paper.

This investigation was performed to evaluate the effectiveness of detecting air leaks in typical constructions through the measurement of sound transmission. The sound transmission of various slits was measured. These were designed to simulate field constructions. Due to the fundamental difference between steady air-flow and sound propagation, it was concluded that the method fails, particularly in the case of foil-covered slits and slits coupled to damped cavities.

A demand controlled air ductwork should be so dimensioned that the flow controllers have good flow and acoustical operation conditions. From the air flows in a room and its highest permissible sound level, the highest differential pressures allowable to the air flow controllers (duct air flow controllers and terminal devices) are selected.