Kucera M., Novy R.

In most cases HVAC equipment has to be provided with silencers. In compliance with development of technology most buildings are now currently equipped with air conditioning systems which require large sections for distribution ducts with built-in silencers. At present this creates great pressure on a minimization of the overall size of silencers in ducts. The present paper deals with mutual relations between acoustic requirements on silencers and determination of their hydraulic resistances. In conclusion the paper presents a concept of the evaluation of silencers by means of a so-called quality factor which essentially covers both their acoustic and hydraulic properties. Simultaneously on the basis of experiments various modifications are compared of baffle-type silencers namely with respect to a minimization of hydraulic resistances.