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| Vacuum Cleaner "Horsepower" |
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| Kleinstein:
50% efficiency is about right for a cheap universal motor at there nominal power. Better ones may reach some 70%. The electrical nominal of some 1100 VA (9.9 A at 115 V) is about normal for the shop vacuum cleaners, so is the size of the motor. For the peak power they say to include the inertial. So this would be essentially the mechanical strength of the axis times the maximum speed. So this would be effective if you suck in some hard object to suddenly blockade the motor. So the more HP the more of a destructive event when shit happens. In the US this is part of the stupid marketing too many buyers are susceptible to. Just remember the larger the letters the more suspicious one should be. For the professional cleaners in Europe they usually give the maximum pressure and maximum air flow, so both of the extremes with high and low air flow. This are more like the numbers you want to compare. |
| SiliconWizard:
As said above - if the figure was right, assuming ~50% efficiency, that would be a something like 6.7kW at the mains plug, or ~60A @110V. Sounds like a bit much for a poor mains plug. |
| james_s:
--- Quote from: SiliconWizard on March 22, 2020, 05:38:21 pm ---Yep. Then it's either a complete lie, or the thing must be drawing so much current from mains that it would blow everything up in a second. :-DD --- End quote --- They find all sorts of clever ways to inflate the number. It's probably something like motor output supplied by a high current source under whatever load results in maximum mechanical energy being delivered for some fraction of a second before the motor burns up. Universal motors can be pushed far beyond their ratings if you don't care how long they last. |
| james_s:
--- Quote from: Someone on March 22, 2020, 06:05:41 am --- --- Quote from: james_s on March 22, 2020, 02:45:28 am --- --- Quote from: Cyberdragon on March 22, 2020, 12:32:17 am ---It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc. --- End quote --- Sure but which one of those do you use in order to meaningfully assess the cleaning efficacy of a vacuum cleaner? The actual performance is going to depend on many factors and a vacuum cleaner optimized to deliver high flow, high static pressure or some other number may not clean any better than one with much lower numbers. You know vacuum cleaner makers would optimize for high numbers over actual cleaning ability, I don't think it would be any more useful than the amps or horsepower. --- End quote --- All hail the Airwatt: https://en.wikipedia.org/wiki/Airwatt --- End quote --- I'm still skeptical of the usefulness of that although it's at least something. The nozzle characteristics and beater bar/brush head design has a great deal of influence on the efficacy of a vacuum cleaner for cleaning. The same vacuum cleaner can perform vastly differently connected to different brush heads and in the case of the typical domestic upright vacuum the brush head is an integral part. Two units with the same Airwatt rating may not perform anything alike. |
| Zero999:
--- Quote from: james_s on March 22, 2020, 07:25:41 pm --- --- Quote from: Someone on March 22, 2020, 06:05:41 am --- --- Quote from: james_s on March 22, 2020, 02:45:28 am --- --- Quote from: Cyberdragon on March 22, 2020, 12:32:17 am ---It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc. --- End quote --- Sure but which one of those do you use in order to meaningfully assess the cleaning efficacy of a vacuum cleaner? The actual performance is going to depend on many factors and a vacuum cleaner optimized to deliver high flow, high static pressure or some other number may not clean any better than one with much lower numbers. You know vacuum cleaner makers would optimize for high numbers over actual cleaning ability, I don't think it would be any more useful than the amps or horsepower. --- End quote --- All hail the Airwatt: https://en.wikipedia.org/wiki/Airwatt --- End quote --- I'm still skeptical of the usefulness of that although it's at least something. The nozzle characteristics and beater bar/brush head design has a great deal of influence on the efficacy of a vacuum cleaner for cleaning. The same vacuum cleaner can perform vastly differently connected to different brush heads and in the case of the typical domestic upright vacuum the brush head is an integral part. Two units with the same Airwatt rating may not perform anything alike. --- End quote --- I agree. That's one of the reaons why the EU decided to cap the maximum power consumption of vacuum cleaners and insist they meet certain performance criteria instead. It got to the point when vacuums were wasting power and contributing to climate change, rather than sucking. |
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