Suction vs Airflow: No high suction needed to clean well

[mike811]

I have done several videos about this topic and results have been always the same. High airflow vacuum with very low suction picks up much better than the low airflow vacuum with the very high suction.
Some people have don't seem to believe this.
Let's take Dyson for example. Dyson vacuums have very high level of suction, but poor airflow. They claim is "highest suction of any vacuum cleaner from the cleaner head". It might be, but it doesn't make it clean well, because of the poor airflow. I have seen many impressive looking Dyson demonstration videos where it agitates and picks up very well from the low pile carpet. Dyson never talk about airflow, because they know, that their vacuums have a poor airflow.
So I tested my highest suction (poor airflow) vacuum what I have (Vax/Hoover Air) vs Kirby G6 with high airflow (poor suction).
You can clearly see the difference.

Special thanks to Bill for inspiring me to do these tests.


http://https//www.youtube.com/watch?v=Fsa2eu4BT_o

 

[wyaple]

Mike,

Your welcome! It's nice to inspire people to see something different. As a reminder, my Dyson DC14 has 112" of lift at the hose and 59 CFM at the nozzle. A G6 (just like yours) has 32" of lift at the motor base (low speed) and 120 CFM at the nozzle. The Kirby deep cleans easily and the Dyson simply can't at all.

He Who Vacuums Last Wins Nothing a Tale of Three Dysons


One Pass Deep Clean Test Kirby Sentria II


Bill

 

[sebo4me]

Thank you for all your videos I have learnt a lot from them

 

[vacuumguy91]

amazing...I've been researching to buy a Kirby...this just motivated me more.. haha thanks so much...wow...

 

[kenkart]

I agree totally

This is why old straight suction uprights clean ok,and why high airflow canisters such as Apexes Strato Cleaner or the Sunbeam Dual Deluxe outclean many newer machines, I have a NSS Pig that really does not have a lot of suction, but the airflow is so great that it outcleans just about anything else.

 

[kenkart]

Also why

A old Kirby with the hose attached will seem to have no power, but will do dusting chores quite well...lots of airflow!

 

[alexhoovers94]

Sebo4me


You are HOT.

 

[sebo4me]

I'm quite cool this morning Alex. Where's the summer gone?!

 

[alexhoovers94]

Haha.

 

[drsnuggle]

Sorry Mike81 for popping up here like this. I am not the one to think suction is more important. Maybe I am burning all bridges here, but I do like to learn. And questioning thingsis a good way to learn.

I do believe that air-flow is the most important factor between suction and air-flow. But one internet site claims that the air-flow is proportional to suction. If I interpret that right then it means that two identical Kirbys, apart from one having higher sucktion than the other, the one with more suction also has more air flow. Hence suction matters if you wish to have great air-flow.

Or have I been missinformed? I have no problem changing my mind so tell me, please.

Another thing some people claim is that suction effects the vacuums ability to pick up larger and more compact things. They claim that is a reason why suction also matters. I do not know so please comment on this as well.

Air-flow is effected by a lot of things, right? Different resistence you may have in the vacuum (small bag, HEPA-filter, multi cyclons). So for general cleaning performance of carpets/rugs I do agree that direct-air is superior to most clean air vacuums.

 

[mike811]

Suction vs airflow

Great to see you here!
Now without the suction there is no airflow and vise versa.
Different vacuums have just a different balance between the suction/airflow.
I am not professional about these. All what I know is from my tests and from the other videos. You have seen that the high airflow/low suction vacuum like the Kirby can remove flour under the carpet much better than the high suction/low airflow vacuum.
Now suction is needed to remove heavy items, but only if the nozzle is VERY close to it. Airflow will move it to the vacuum.
One example: Air driven turbo brush is one that needs both suction and airflow. Because the turbo nozzle has tiny hole where the air goes to the turbine, airflow will be greatly restricted. Suction will force the air through the tiny hole and help the airflow.
However the Kirby (at least my G6) has enough suction and certainly airflow to spin the mini turbo brush quite fast. Full-size turbo brush doesn't spin so well with the Kirby. It's just because of the low suction.
When the Kirby is in the carpet vacuuming mode it has very large diameter and simple "ducting" paths. That way it can keep the massive airflow.

I hope this will answer some of your questions

 

[sptyks]

DrSnuggle:


 


Here are two videos that describe the difference between suction and airflow:


 





 





 


 

 

[drsnuggle]

Thanks sptyks (and Mike81)!

The second video I have seen (great video) and that one is one that made me think.
Suction is measured without airflow, hence resistence within the vacuum should not effect it. So the reason, I think, why bagless has lower airflow then bagged vacuums must be the turbulence created by the multi-cyclons. And that makes me think that mono-cyclons has better airflow than multi-cyclons, but I have no instruments to measure that.

 

[sebo4me]

From what I understand a vacuum cleaner with high suction will have more airflow at the end of the hose than a vacuum cleaner with lower suction.

 

[rolls_rapide]

No.

High suction = low airflow, (e.g cylinder cleaners),

High airflow = low suction (i.e direct air Hoover uprights).

One of the old Hoover Alpina brochures had a graph purporting to show the relationship of airflow to suction.

 

[drsnuggle]

An X type graph

Rolls_rapide
I think I got it now. The graph would be like an x, one goes up then the other one goes down. A vacuum normally has strong suction but rather low airflow, but a kitchen fan has low suction and high airflow, right?

So suction and airflow co-exists but how do a vacuum buyer know the optimal balance between suction (water lift) and airflow? Maybe a stupid question if the seller specify both measures on the box of the product. Or is it enough to just look at the airflow?

This is so interesting and it has been covered before on this forum I can see.
At some point I thought airwatts was enough, but now I don't think it is particulary useful.

 

[n0oxy]

suction and airflow

You actually need both to clean effectively. An example of all airflow but no suction would be a table fan, lots of air but not as much force behind it. You could also see this with a canister vacuum by opening the bag door and turning it on, you will feel lots of air moving but not a lot of force. Similarly, if you use a very small attachment you will have lots of suction but not as much airflow, it will feel powerful if you put your hand over it, but other than that, it won't clean very well. The dirty air uprights are very good at cleaning carpets, but for attachments, a canister will be far better. This is why I like canister vacuums, especially a power nozzle canister for cleaning carpets, they provide high airflow and high suction.
Mike

 

[wyaple]

In case anyone missed my measurements

here's something to chew on:

Dyson DC14 has 112" of lift and 59 nozzle CFM
Hoover Tempo has 80" of lift and 80 nozzle CFM
Hoover Convertible has 25" of lift and 107 nozzle CFM
Kirby G6 has 32" of lift and 120 nozzle CFM

The Dyson cleans the worst, the Tempo is OK, the Convertible is very good and the Kirby is fabulous. You could also notice that as suction increases, nozzle CFM decreases. These machines are different types of course...

Bill

 

[floor-a-matic]

high airflow=high suction

a ridgid shop vacuum (when using the larger diameter hose) but a bit less airflow when using smaller diameter hose