Direct air motor vs Clean air motors

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Drifting, Drifting

Thread is drifting.

Back to air flow.

And BTW, you can have a beach of sand in your carpet. A carpet can hold ond and one half times it's own weight in dirt and still look clean to the naked eye.
 
Suction vs Airflow

Harley is absolutely correct when he explains the concept of Suction vs Airflow!


 


Here's another way to look at it: A Tornado is a whirl of wind. There is almost no suction involved, but a Tornado can pickup a house and carry it 100 yards with very little or no


suction.


 


Take a look at your average Dyson. There's lots of suction as measured in inches of water, but take out your Baird Meter and measure the Airflow and you'll find there's very little.


 


Now look at your Kirby or metal Royal and you'll see these numbers are reversed. There's very little suction, but the Baird meter is nearly pegged at "10". Now as the brushroll, spinning at 3900 RPM, brings the dirt to the surface of the carpet, all that Airflow picks up the dirt (just like a tornado) and carries it through the fancase and into the bag. And that's why Airflow is more important than suction.


 
 
So where does the airflow come from Stan? It comes from the fan creating low pressure which produces suction without suction there will be no airflow! So they are both tied together one is not more important than the other.
 
Marcus, I want you to understand this concept, so please read slowly what Harley wrote here: 


<a style="font-family: 'Times New Roman'; font-size: medium; font-weight: normal; line-height: 20px;" name="start_28347.317402"></a>


"You can also have airflow, like a dryer, where it moves 180 CFM, but it is mass air flow [COLOR=#ffff00; background-color: #000000]very little suction because the air is being replaced as quickly as it is being removed.[/COLOR] The air flow carries out the damp warm air in a dryer, as is the air flow that moves the dirt off the carpet and into the capture system." 


 


Another way to look at it is when you first turn on a Kirby, and the fan starts to spin up, there is a brief moment of suction that starts the air moving through the machine. Once the Airflow reaches full speed, the suction drops off to a small amount<span style="font-size: 14pt; color: #ff0000;"> because the air inside the floor nozzle is being replaced as quickly as it is removed. [COLOR=#000000; font-size: 12pt]Once air is constantly moving at full speed, there is no more need for lots of suction. The reason why the Kirby and Royal have so much airflow is because the opening to the fancase is a full 2 inches in diameter compared to Dyson and similar machines which is between an inch and an inch and a quarter. The Bell Shaped nozzle amplifies the airflow as well. Read the posts above, there is a scientific formula that proves this.[/COLOR]</span>


 


 
 
but you can have suction without air flow

A dead suction, such as the demo where they stick an electrolux to the wall. There is no air flow.

When David Oreck picks up a bowling ball with his hand portable--no air flow.

A water pump is a good example: though I know it is not pumping water, it is moving fluid. Which air is a gaseous fluid. The pumps impeller creates a vacuum, whereas the ambient air pushes the fluid water up the pick up pipe, through the pump and out to the output. A water pump is limited to how much "vacuum" or suction it has due to the atmospheric pressure is what "pushes" the water up from the well when the pump creates the suction. Because it is limited to the atmospheric pressure wells deeper than 25ft, are not considered a shallow well and requires a different type of pump or submerged pump.

A submerged pump can be lowered into the well where it is closest to the water level and now you can go 200, 300, 400 ft or more and not be dependent on the atmospheric pressure, because the pump itself is "pushing" the water up the pipe to the surface.

I would equate the Submerged pump to a direct air machine where the business end is very close to the area of work, and the exhaust is pushed after that. This is why it doesn't have to "Suck" that hard, only move the air.

A Surface, or shallow well pump is very similar to a clean air machine as it has to suck the water through a tube, dependent on the atmosphere to push and there is only so much atmosphere, but then a short distance to exit.

All the pump has to do is displace the water and the atmosphere pushes additional water in it's place. This is the same with a suction cleaner. The spinning fan displaces air and since nature abhors a vacuum the atmosphere quickly replaces the air with more so a larger fan with a somewhat restricted intake will create a greater suction due to our good friend Bernoulli, but if you shut off the air flow the suction is only that of the displaced air and the atmosphere around it.

Now if you were to leave your water pump running and shut off the water valve, the pump would still be trying to displace the water, but with no where to go it would only cavitate within the chamber, but nothing would move no flow, no vacuum.

So in close, yes you are correct they are dependent on one another, but as indicated as flow increases suction drops as nature only allows so much atmosphere. As we restrict the airflow as through an old fashioned carburetor air horn vacuum increases, but air flow decreases.




[this post was last edited: 3/4/2015-14:43]

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It's amazing what you can remember from 9th grade Physical Science class. I remember the whole Water well/pump atmospheric pressure chapter. Didn't care for Mr. Schoonover who taught it that much, but that's a different story.
 
Haha our chemistry teacher had a nervous breakdown cause of us. Oh dear. I was so immature back then. Hard to believe isn't it :-)
 
Using the water pump example

If you were to have a deep well pump that lifted the water, and then a shallow well pump to relieve the back pressure by moving the water away so the deep well didn't have to work so hard they would work in tandem, much like the tandem air machines.  


 


 


 


 
 
Sigh...here we go again...


"Sprockkets, I'm afraid that you are still wrong. It seems you are confused and believe that suction and airflow are the same thing. They are not. In order to clean carpet really well you need 3 things:"

Seeing how I clearly explained what "suction" is and how it is properly measured, via inches of water column, and air flow, in CFM, and when combined with ductwork measurements give true CFM in my HVAC work, yeah, I think I clearly understand it, probably better than you do.

Depending on the a/c system, adding a filter does one of two things. One, on a PSC motor setup, will cause more resistance, cause less air flow, drop static pressure, then lower fan amps. Two, on a true ECM motor, will cause again, a resistance, the motor senses this and increases fan speed to compensate, increased fan amps, and increased staic pressure, until it hits 1 inch of water column.

"The Baird meter measures Airflow and that is what's most important."

No it doesn't! It's so ridiculous that you can't see that. From what you've shown me it is a simple diaphram on a spring. It's pretty much is a pressure tester with an arbitrary measurements that will only apply to itself. The more suction generated moves the diaphram which in turns translates into CFM, but the scale is aribtrary and only useful when comparing another machine. Unless you have more info on it, it can't tell you what the real CFM is anyway!

Here, let's explain this even further.

In electricity, Voltage is pressure or suction, depending on how you look at it.
Current would be the airflow or CFM.

In water flow, pressure is well, obvious. GPM would be airflow.

In certain applications, you need high voltage but low current. Stuff like flourescent lights do this. In weilding, you need high current but low voltage.

You essentially are saying that airflow is all that matters, but obviously that isn't true. You can have all the air flow you want, but any form of resistance to it, with that vacuum bag, that nozzle on the carpet, or any other forms of it, require overcoming with pressure.

Just by looking at the fans in the Royal, Kirby or most any direct air vacuum, and they are geared for airflow due to their sheer size. The small fans in bypass vacuums are geared to high pressure due to the amount of resistance they have to overcome.

BOTTOM LINE: YOU CAN'T GENERALIZE. Just because it is bypass or direct air means nothing. There are examples of both that can suck badly at what they do.

Oh and btw, try getting your kirby or royal head underneath anything like this! I'll take a Felix over any vacuum any day for this office I clean!

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If you are looking for the most airflow and the deepest clean you would go for a Kirby, if you don't need the deepest clean but want a more user friendly cleaner that still cleans very well, deep enough for most, go for a Sebo.
 
Sprockkets:  I agree that as airflow decreases, suction increases and vise versa. BUT, I also believe that Airflow and agitation are the two most important ingredients needed for a good deep clean. Bag and nozzle resistance does increase suction a little bit on a Direct Air vacuum, but the amount of airflow through the nozzle along with a well designed brushroll cleans carpet the best.


 


Marcus:  For once I fully agree with your statement on Kirby vs Sebo. Actually, after all I've read on this Forum about the Sebo Felix, it sounds like a fantastic machine and I would love to try one out sometime, but they are horribly expensive here in the U.S. The only thing that would bother me about the Felix is the small but expensive bags.


 


 


 


 
 
You agree with me?Am I dreaming? :-)

The Felix in the UK you can pick up for around £200 and the bags work out about a pound each. But they are a lot more expensive over there sadly, not as expensive as Miele though. But you do see used ones on EBay. You see more X4`s over here.
You could probably pick up a used X4 for £100. I've seen models just a year or 2 old for that price.
 
The U.S has commercial versions of the Felix, but they're not as versatile in my experience. They have fixed suction, non-brush roll on/off button and no 3 point neck height adjustment for the handle.

Not only sold under Windsor Axxcess, but also the previous "Flexamatic" label and Dr Schutz with the Dart re-labelled "Carpetwise." Karcher U.S ALSO sells a commercial version of the Sebo Felix.

Generally I find a box of Felix bags lasts me a year and a half to 2 years before a new box is required. You get 8 bags in a box which is double the quantity you get with Miele. SEBO don't use litres or quarts as a way of understanding longevity per bag; it really depends on what your home has in terms of the amount of dust. At the very least, a SEBO Felix dust bag in my experience lasts 2.5 months before requiring to be changed, which puts it on a par with Miele's FJM dust bags.

Some bags my old Felix has had has gone on for 4 months!
 
@sptyks Yes that is true. Or another way of thinking is there is a lot of potential with high suction, but without a clear path for it to go, air flow suffers.

Again, only gripe with Kirby is their network of salesman to sell the device. One quick story was my friend who will never let her kirby go, got a call from them a year or so later after buying hers getting her to upgrade. Then she turned their own words against them saying you told me this would be the last vacuum I'd ever buy! That shut them up :)

I'd say the best price for a felix is $400 (OTOH Dyson charges more for his stuff but the build quality isn't up to sebo's standards), and why it costs more here in the US is beyond me. Heck, my congregation has a special agreement with Windsor and got the Axcess for $220 new. Otherwise I've seen it for $450 or so new, but you don't get the parquet brush or the adjustable handle and the power head can't be switched off.

So I guess that is why a lot of you have multiple vacuums for different days huh :)
 
Dyson charges more but is build quality isn't up to seb

That's not true at all Dysons got the same build quality maybe even better can't confirm as I don't own one. is just more flexible so it can accept more force without snapping. If you don't even own one can you not comment on something if you don't own because that's how arguments are started. :)
 
Nope, I don't own one. Just used several and while yes, they use tough plastic, everything else is lacking.

It really isn't a jab against them as they aren't made for commercial use. They have so many bells and whistles on them that there are so many points of failure. I've seen one though be used in a restaurant, but that's it.

It is also hard to generalize with them too, as in the past they used cheap chinese motors, or ones by panasonic which should be better, to now their in house brushless motors on some of their stuff.
 
i agree with you but only on the older models as in the last few years dyson has come a long way they have improved in every way I really don't like the older models.but if you don't own one of the new one can't really comment on them.
 
I guess if a box of Felix bags lasts more than a year that's not so bad. There is a Sebo dealer about 20 miles from me, but he sells the Felix for around $600.00 which is too rich for my blood.


 


I bought all my Kirby's on ebay for between $50 and $190 except my G3 which I found in the trash. It cost me about $60 for the parts to get it running like new.


 


I have no desire to own a Dyson, mainly because it's bagless and I don't care for bagless machines. The exception being a Hoover WindTunnel Air that I got cheap. It's great for quick pickups and vacuuming out the shakeout bag of my vintage D50. I empty the Hoover in the trash bin in the laundry room of my apartment building so the dust cloud doesn't come near my very clean apartment.


 
 
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