Vacuum Cleaner "Horsepower"

[Cyberdragon]

Just like space heater "room size" (see Technology Connections), we have another example of BS marketing wank from appliance companies.

[Zero999]

I haven't bothered to watch the video, but it's BS.

1hp = 745.7W

What's the maximum power output of typical mains sockets in the area it's sold in?

UK
230V 13A = 2990W = 4hp

Europe
230V 16A = 3680W = 4.93hp
But the power consumption by vacuum cleaners in the EU is capped at under 1kW, if I remember rightly.

US
120V 15A = 1800W = 2.41ph

Perhaps this should be in the dodgy technology section?

[SiliconWizard]

Hmm. About 3 kW seems a lot for a vacuum cleaner. Most of house vacuum cleaners are like half that or less.

Items meant to be plugged in basic mains sockets rarely draw over 2 kW or so. But a few are close to this: some hair dryers are rated close to 2 kW.

While this thing would probably have no market and would even be non-compliant in many parts of the world, it could still be real. It would just be illegal to sell it.

[NiHaoMike]

Marketing indeed. Here's a central shop vac with a real 5HP motor:

[Cyberdragon]

I haven't bothered to watch the video, but it's BS.

1hp = 745.7W

What's the maximum power output of typical mains sockets in the area it's sold in?

UK
230V 13A = 2990W = 4hp

Europe
230V 16A = 3680W = 4.93hp
But the power consumption by vacuum cleaners in the EU is capped at under 1kW, if I remember rightly.

US
120V 15A = 1800W = 2.41ph

Perhaps this should be in the dodgy technology section?

No, it's worse than that, watch the video.

They claim 4.5HP MECHANICAL POWER with a basic brushed motor (measured at 51% effeciency). There is even fine print claiming some sort of "testing" and that it's some sort of vague "peak power". He called the company (ShopVac in this case) to ask about it and they said they weren't allowed to disclose that information.

The "4.5HP" motor burned out at 1.68HP mechanical force.

[SiliconWizard]

They claim 4.5HP MECHANICAL POWER with a basic brushed motor (measured at 51% effeciency).

Ahaha. No question then. It's pure fun!

[mzzj]

Americans and their silly marketing horsepowers.
Who rememers PMPO watts in amplifiers? 

[amyk]

If you measure the DC resistance of the motor, use P = V^2/R and convert that to HP, that might be where the 4.5HP comes from. 4.5HP is around 3.4kW which gives a winding resistance of 4.2 ohms, seems about right for a low efficiency universal motor.

[Cyberdragon]

If you measure the DC resistance of the motor, use P = V^2/R and convert that to HP, that might be where the 4.5HP comes from. 4.5HP is around 3.4kW which gives a winding resistance of 4.2 ohms, seems about right for a low efficiency universal motor.

No, the fine print on the box says it's motor output.

[NiHaoMike]

There's a joke that those crazy HP values are obtained with strange testing done only for marketing purposes.
http://repairfaq.org/sam/humor.htm#hum011

About Sears Shop Vac HP Ratings
(From: Kevin AstirCS "1U" KO0B (kferguson@aquilagroup.com).) I note that air compressor manufacturers have taken after the vacuum sweeper folks, and are re-inventing the horsepower. Imagine, 6HP at 15A, 115VAC!

(From: sam).

Have you seen Sears shop vacs lately? I think they are also up to 6 HP. Every week or so, they seem to come out with one that is a little higher in their HP ratings - I guess internal cold fusion or something.

(From: Pin 2 Hot (pinksnd@io.com).)

Let's see, RPM X Torque = Horsepower.

Thus: No-load RPM X Locked-rotor Torque = Sears Horsepower

Notes:

    testing done at 177V DC, equal to peak of 120V AC (AC-DC motors).

    Sears Horsepower: How "hoarse" you get trying to talk over one of their shop-vacs while it's on.

Or maybe it's got something to do with vacuuming performance out at the stables.

[engrguy42]

Awww, come on. Don't be so rough on them. When they say "horsepower" they're just referring to a very small horse. Y'know, like those miniature ones that are only like 1 meter tall. They have power too don't they? Don't be so judgemental. 

[WattsThat]

It’s the same kind of marketing BS that has the brewers battling it out for the biggest lie in who has the lowest carbohydrate content beer.

Pure BS like “2 grams of carbs and 90 calories”. Yeah, so that’s a lot of fat or protein making up the remaining 82 calories that’s unaccounted for. Unless of course they’ve come up with a new basic food group that we haven’t heard about 

[james_s]

This is nothing new, it's no different than the cheap amplified speakers that claim "600 Watts!" yet run off a small wall wart. Vacuum cleaner makers have listed the amps and shop vacs have been rated in bogus horsepower for decades. One of the issues is that there isn't really a standard measure of effectiveness for a vacuum cleaner and most consumers have no idea what a horsepower is anyway in useful terms. They're going to end up being rated in some arbitrary unit anyway.

[Cyberdragon]

This is nothing new, it's no different than the cheap amplified speakers that claim "600 Watts!" yet run off a small wall wart. Vacuum cleaner makers have listed the amps and shop vacs have been rated in bogus horsepower for decades. One of the issues is that there isn't really a standard measure of effectiveness for a vacuum cleaner and most consumers have no idea what a horsepower is anyway in useful terms. They're going to end up being rated in some arbitrary unit anyway.

It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc.

[james_s]

It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc.

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.

One relatively easy thing they could do is require the horsepower rating if used to be actual rated continuous horsepower of the motor. Still not very useful but at least based on something.

[coppercone2]

on a lighter note, my shop vac turned into a shot gun when I turned it on spewing acorns all over because of a squirrel stash.

[Someone]

It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc.

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.

All hail the Airwatt:
https://en.wikipedia.org/wiki/Airwatt

[Zero999]

It’s the same kind of marketing BS that has the brewers battling it out for the biggest lie in who has the lowest carbohydrate content beer.

Pure BS like “2 grams of carbs and 90 calories”. Yeah, so that’s a lot of fat or protein making up the remaining 82 calories that’s unaccounted for. Unless of course they’ve come up with a new basic food group that we haven’t heard about 

Seems sensible to me. The alcohol is responsible for the remaining 82 calories.
https://en.wikipedia.org/wiki/Alcoholic_drink#Food_energy

[unknownparticle]

Similar BS to hobby air compressors marketed with outrageous HP claims!  Break it down and most of them produce less than half what the makers claim, then apply a duty cycle factor and they are a joke.

[SiliconWizard]

If you measure the DC resistance of the motor, use P = V^2/R and convert that to HP, that might be where the 4.5HP comes from. 4.5HP is around 3.4kW which gives a winding resistance of 4.2 ohms, seems about right for a low efficiency universal motor.

No, the fine print on the box says it's motor output.

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.

[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]

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.

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]

It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc.

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.

All hail the Airwatt:
https://en.wikipedia.org/wiki/Airwatt

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]

It's a device that creates airflow. There are several ways of measuring it, flow volume, static pressure, exc.

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.

All hail the Airwatt:
https://en.wikipedia.org/wiki/Airwatt

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.

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.