Author Topic: Bullshit units of measure  (Read 6697 times)

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Offline ogden

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Re: Bullshit units of measure
« Reply #50 on: October 16, 2022, 02:12:16 am »
Other manufacturers specify suction power simply in Watts. Air Watts is just fancy name for same measure - to give option for Dyson sales to convince that it is not :D
 

Offline boB

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Re: Bullshit units of measure
« Reply #51 on: October 16, 2022, 02:24:04 am »
There is power in the wind...

For wind turbine use, the equation is,   Power (W) = 0.6 x Cp x N x A x V^3

Related I'm sure.

K7IQ
 
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Offline Psi

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Re: Bullshit units of measure
« Reply #52 on: October 16, 2022, 02:59:40 am »
Other manufacturers specify suction power simply in Watts. Air Watts is just fancy name for same measure - to give option for Dyson sales to convince that it is not :D

Yeah, that's a pretty common marketing practice.
Invent a difference that doesn't exist, then use the difference to show how amazing your product is verses your competitors products.
Usually done by companies when
- There's no true benefits over the competitors products
- When all the benefits that do exist over the competitors products are things no one cares about.
- When investors want maximum returns at all costs and don't care what a company does as long as they can keep getting away with it.
« Last Edit: October 16, 2022, 03:01:36 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Online wraper

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Re: Bullshit units of measure
« Reply #53 on: October 16, 2022, 06:59:35 am »
Other manufacturers specify suction power simply in Watts. Air Watts is just fancy name for same measure - to give option for Dyson sales to convince that it is not :D

Yeah, that's a pretty common marketing practice.
Invent a difference that doesn't exist, then use the difference to show how amazing your product is verses your competitors products.
Usually done by companies when
- There's no true benefits over the competitors products
- When all the benefits that do exist over the competitors products are things no one cares about.
- When investors want maximum returns at all costs and don't care what a company does as long as they can keep getting away with it.
Just FYI Dyson did not invent air watts, and it is a proper unit of measure per ASTM https://tajhizkala.ir/doc/ASTM/ASTM%20F558__13.pdf. If some manufacturers drop "air" in the wording, it's not Dyson's fault. I rather think that two power ratings both labelled in watts cause more confusion to consumer.
 
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Offline ogden

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Re: Bullshit units of measure
« Reply #54 on: October 16, 2022, 08:07:34 am »
Just FYI Dyson did not invent air watts, and it is a proper unit of measure per ASTM https://tajhizkala.ir/doc/ASTM/ASTM%20F558__13.pdf. If some manufacturers drop "air" in the wording, it's not Dyson's fault.
Yeah, cannot argue. Thank you for pointer to ASTM doc.
 

Offline rsjsouza

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Re: Bullshit units of measure
« Reply #55 on: October 16, 2022, 10:16:23 pm »
Strictly to the topic of the thread, the bullshit is the motivation for the topic itself.  :box:

To the discussion about Dyson, I echo other comments here regarding durability: having used one for about 14 years I found out its maintenance was not bad at all, with the occasional hair cleanup of the brush and the chamber filters. It was sold just because the missus wanted one with a HEPA filter.

We also are on our second battery powered unit (the first one broke on a stupid accident after 10 years) and both work really well.

Regarding the robotic stuff, I got very tired of having to unclog/clean the brushes and the dust compartment four or five times at every cleanup. It might work for a house with a single person but, when you have three long-haired girls, it is quite impractical.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline Berni

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Re: Bullshit units of measure
« Reply #56 on: October 17, 2022, 05:17:27 am »
Id say Air Watts are a good name because you don't want to confuse it with electrical Watts.

Vacuum cleaners have had a watts number all over the box for a very long time, but this number was the watts of electrical input energy and it was obviously much larger. You wouldn't want costumers confusing the two since the electrical watts is a significantly bigger number.

It is also perfectly possible that back then some manufacturers made less efficient motors on purpose just to get the watts number up. These motors have a ton of airflow trough them and i remember some vacuum cleaners blowing outright hot air out of them.
 
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Offline TheNewLab

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Re: Bullshit units of measure
« Reply #57 on: October 17, 2022, 05:33:39 am »
OK This on e really hurts, I hit my head on the chair laughing. no acro for that is there.
There is power in the wind...

For wind turbine use, the equation is,   Power (W) = 0.6 x Cp x N x A x V^3

Read https://tajhizkala.ir/doc/ASTM/ASTM%20F558__13.pdf  still does not really inform say 95% of potential buyers..Why not something simple like PSI? or what HVAC techs use in testing vent draw and volume?  I know Dyson makes great products, but "Air Watts" is. well, I read that entire PDF quickly and it is way more than I want to know. give me PSI and I understand right away
 

Offline Berni

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Re: Bullshit units of measure
« Reply #58 on: October 17, 2022, 05:54:26 am »
Problem is that fans/pumps have characteristic curves that can vary in shape a lot.

It is easy to make a pump that makes a lot of pressure at low flow rate (this is a fridge compresor) and it is easy to make a pump that moves a lot of volume at very low pressure (this is a desk fan). Both of these beat a vacuum cleaner at pressure or volume. But what makes a vacuum cleaner a vacuum cleaner is that it can create a lot of pressure while simultaneously moving a lot of volume.

Since air watts are pressure and volume multiplied together means that both of them have to be a large number for the result to be a large number. So it is actually a very smart way to measure the performance.
 
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