Why is airflow always measured?

[cheesewonton]

Incidentally, It's not clear what that "150 Watts of suction power"

It refers to the Suction Work Rate according to the Japanese standard.

 

[cheesewonton]

This is nice to see, but it's not relative cleaning performance data.

That is the most uninformed statement imaginable. Without suction and airflow you don't have cleaning power. Pretty basic stuff.

 

[cheesewonton]

Watts can technically be measured anywhere in the system"

But again the Japanese standard measures Suction Work Rate at the attachment end. The Japanese standard is very detailed and specific that way and why comparisons of vacuums rated by the Japanese standard are objective.

 

[Vacuum Facts]

It refers to the Suction Work Rate according to the Japanese standard.

I'm not convinced from their advertising, but it is believable. Also doesn't translate into cleaning performance on carpets.

This is nice to see, but it's not relative cleaning performance data.

That is the most uninformed statement imaginable. Without suction and airflow you don't have cleaning power. Pretty basic stuff.

What you said is true, but cleaning performance needs to be measured directly since, as discussed in the previous response, there are other factors associated with the cleaner head. Direct measurements are needed, not values from indirect variables. The science of this is well known and discussed in the lecture you write off as complicated. Well the real world is and if you want to understand it, an investment in education is needed. I've kindly made it available for those who want to learn, and it's accessible to the age of about 16.

Watts can technically be measured anywhere in the system"

But again the Japanese standard measures Suction Work Rate at the attachment end. The Japanese standard is very detailed and specific that way and why comparisons of vacuums rated by the Japanese standard are objective.

Again true. No argument from me. However, their standard measures for effectively one particular use case that isn't universally applicable to all situations (unlike the ISO). And it's only relevant for above floor cleaning. You claim it's for a tool sealed to a surface (which makes sense), but this is different to tool extracting from a deep crevice. Air watts are fixated on too much and not many seem to understand their value. Their real value for floor cleaning is outlined in the lecture associated with various low resistance flooring that allow high air currents, and more air watts sustains suction and air speed. All well understood and has been for a few hundred years.

 

[Absolute Rainbow]

@cheesewonton @Vacuum Facts please tell us all the differences between the Japanese Suction Work Rate and simple airwatts, so people would know, notice and be able to distinguish the two.

Also, here's a video for dummies, made by none other than @Vacuum Facts:

 

[cheesewonton]

@cheesewonton @Vacuum Facts please tell us all the differences between the Japanese Suction Work Rate and simple airwatts, so people would know, notice and be able to distinguish the two.

Also, here's a video for dummies, made by none other than @Vacuum Facts:

The primary difference is that the ISO Air Watt measurement is an instantaneous measurement of both airflow and suction at a given diameter orifice. It is a snapshot in time. Vacuum motor manufacturers will take this measurement at different orifice sizes starting at a closed orifice. At that point you get maximum suction and no airflow. Since Air Watts are Suction in Pascals multiplied by airflow in Cubic Meters per Second the Air Watts at a closed orifice is zero. The manufacturer will take airflow and suction measurements at progressively larger orifices and calculate the air watt value for that orifice until they reach a maximum orifice size, typically 50-52m at which point suction is nearly zero and airflow is maximum. They will also plot Airflow and Suction vs Orifice size. Where those graphs intersect, typically around 20-25 mm orifice size maximum air watts is achieved.

By comparison the Japanese standard measures maximum sealed suction at the hose end or the orifice in the nozzle of an upright, and they also measure the quantity of air that flows through the hose or suction nozzle over a period of time. This compensates for the difference in the speed of air flowing through a hose or tube from the center where it is highest to the walls where it is nearly zero. Instead of measuring air speed at the center and applying a rule of thumb correction factor the Japanese simply measure the total volume of air that flowed over a period of time. The measured suction and air volume are multiplied together and this value is multiplied by a factor to arrive at their Suction Work Rate.