Hi,</p><p>To my mind its all unnecessary. It's all an example of --"If you can't dazzle 'em with brilliance, baffle 'em with BS."</p><p>According to the One Look" online dictionary an air watt is:</p><p>an engineering unit used to express the effective cleaning power of a vacuum cleaner or central vacuum system. The air watt is practically the same as the ordinary
watt. Measurements of vacuum power, however, are computed from English units using the following formula established by the American Society for Testing and Materials (ASTM): power in air watts equals 0.117354·F·S, or very nearly F·S/8.5, where F is the air flow in the system in cubic feet per minute (CFM) and S is the suction pressure in
inches of water column (in WC). This definition makes the air watt equal to 0.9983 watt. </p><p>Hope you understand that -- I don't.</p><p>Best,</p><p>Venson
I follow the math fine. Looking at this air watts takes into account air flow and suction. Amp power ratings measure the potential and power useage of the motor only, much like the Brake horsepower rating for cars. Which makes sense because if that were not the case any 12AMP motor would have a 1300+ airwatt rating which is obvisouly not the case. I think that clears things up a bit. I'm still a little confused as to how air watt ratings are tested though. With all things considered two brand new vacs with like powered engines and similar flow/air routing would have the same air watt rating. Are central vacs and dysons tested over time and then give a averaged air watt rating? In the telecomm industry we have average Bit Error Rates which is a number derived over time to provide 99.999% availability of a circuit. Is this what air watts is then for vacs?