period five
Review
notes
Fundamentals of HVAC Acoustics
period five
Review
Figure 68
We will now review the main concepts that were covered in this clinic on the fundamentals of HVAC acoustics.
Review—Period One
ISound power
KAcoustical energy emitted by source
KUnaffected by the environment
KCorrelates to bulb wattage
ISound pressure
KPressure disturbance in atmosphere
KAffected by strength of source, surroundings, and distance from source
KCorrelates to brightness in a particular location
Figure 69
Period One explained some of the basic concepts of sound. Sound is the audible emissions resulting from the vibration of molecules within an elastic medium. It is generated at many different frequencies at the same time. Noise is defined as unwanted, or obtrusive, sound.
Sound power and sound pressure are both terms that are used when describing sound. Sound power is the acoustical energy emitted by the sound source and is not affected by the environment. Sound pressure is a disturbance in the atmosphere and can be measured directly. Its intensity is influenced not only by the strength of the source, but also by the surroundings and the distance from the source to the listener. Sound pressure is what our ears hear and what sound meters measure.
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