Engineering Acoustics

13Design of Air‐conditioning Systems for Noise and Vibration Control

13.1 Introduction

There is widespread use of heating ventilation and air‐conditioning (HVAC) systems in a variety of small and large buildings. The main consideration facing the designer of such systems is to ensure that the plant provides the required amount of heated or cooled air throughout the building and does not create objectionable noise or vibration either in the areas served by the system or in adjacent areas. Because air must be supplied (and in many cases extracted) by a fan of some kind (either axial, centrifugal, or mixed‐flow), it is inevitable that some noise and vibration are generated. It is becoming common practice to use systems with very high airflow velocities which introduce additional problems due to noise generated by the turbulent airflow, which is created. However, despite the many difficulties that may be encountered, the noise produced by the system can be controlled if the system is correctly sized and care is taken to ensure that all elements of the system are properly installed. Air‐conditioning also makes it possible to use sealed windows, thus giving good sound isolation from most of the outdoor noise. This can be important with buildings situated close to airports, railroads, and highways.

Once a completed HVAC system has been installed in a building, it is often very difficult and expensive to correct noise and vibration problems. Thus, great care should be taken at the ...