Decibel Levels

For some time now, Smith’s has emphasized the fact that our fan and motor assemblies are capable of delivering the BTU/hr rated capacities at the lowest decibel levels as compared to any like product. This is why we named our kickspace heaters the “Quiet-One”. In order to provide you with more exacting data, we have tested the decibel delivery of our kickspace units. These tests yield at 38 dBA level on high speed and a 33 dBA level on low speed. The lowest in the industry!

The procedure used to measure our kickspace, which was in keeping with standards developed to measure all heating and air conditioning equipment, requires the installation of a microphone at a range of 6’ from the terminal unit. The height of the microphone must coincide with the center of the supply air outlet grille. The room the unit is measured in is reasonably well furnished (not a clean empty room) as this prevents resonance and echo which are not typical of a normal living space. The unit is then operated under simulated real time conditions and dBA ratings are taken throughout a 75 hour period. With this standard measurement technique, our “Quiet-One” KS units clocked in at 38 dBA on high speed and 33 dBA on low speed. Our nearest competitor clocked in at 44 dBA on low speed and 49.5 dBA on high speed.

In order to better understand the importance of decibel readings (i.e. how they relate to quietness) we include the following definitions and information for your review.

“Sound Wave” – The pressure area produced by mechanical vibration which moves through a medium such as air causing the reaction in the ear which the brain interprets as sound. A sound wave has a length (wave length), amplitude and a frequency.

“Wave Length” – determines the frequency of the sound. A sound with a longer wave length has a lower frequency. Irreversibly, one with a short wave length has a higher frequency.

“Frequency” – is directly related to the number of cycles per second of the sound wave and is directly related to pitch.

“Pitch” – is the highness and lowness of sound.

“Amplitude” – refers to the height of the sound wave and is directly related to intensity which is measured in decibels.

“Intensity” – is defined as the strength of a sound usually measured by the amplitude of the sound wave in question.

“Decibel” (dBA) – is the unit of measure used to measure the relative intensity of sound. It is approximately equal to the smallest change in loudness that the human ear can detect.

As a rule of thumb, for every 8 decibels increase in intensity there is a twofold increase in the audible sound. See this chart for an example.