Direct Air vs Bypass Air confusion

[durango159]

EurekaPrince

Did you use a Kenmore Progressive canister and that's where you experienced electrical issues???   


 


Kenmore Intuition and Kenmore Progressives are one of the only power nozzle canister vacuums I've heard of to experience electrical issues.  It happens with the wands at the quick disconnect points.  They weren't designed snug enough in the beginning and then consumers abuse the machines by disconnecting the wands while power is still running.  This over time tends to create a short and any plastic in the area weakens over time. 


 


Circuit boards are another one.  The Hoover Windtunnel Anniversary S3670 was plagued by circuit board issues causing loss of power to the power nozzle and also I've seen Electrolux units-- the newer style Eureka made Electrolux units with the circuit boards have issues.   Maybe over course of my new IT career when I complete my studies, I can work to improve this!


 


I have never had an electrical issue with any of my Hoovers, Eurekas, Simplicity or any other canister vac I've used or tried over the years.  I am 34 years old and have been cleaning houses as a side gig since I was 12.  I also sold Rainbow and Filter Queen.  Currently I have 11 power nozzle canisters in the house.  They are my goto machine for thorough house cleaning any cleaning job I do!!   The versatility for cleaning all surfaces quickly and easily, getting under beds, under night tables, carpet or hard floor stairs, removing cobwebs from the ceiling just can't be beat. 


 


I think every household should own a decent power nozzle canister vacuum cleaner!


 

 

[sptyks]

Rob,


 


I'm not sure, but I think the Riccar Radiance Tandem Air may have a bag full indicator. But then it might not be considered a true Direct Air vacuum.


 


 

 

[kirbysthebest]

Usually a direct air, soft bag vacuum doesn't need a bag full indicator.  You can pretty much eyeball, or give it a squeeze  and tell it's full.   You can also tell when you notice a decrease in performance.  


 


 

 

[n0oxy]

canisters

Like Rob, I'm a huge canister fan, if you have all hard wood floors, you may not need a power nozzle, but canisters are by far more flexible than uprights. With a power nozzle, they will clean ccarpets as good as, if not better than uprights, and you can get under things easier without moving them. For above the floor cleaning, canisters are much better. While many uprights have on board attachments, they're not as easy to use and don't have as much reach. And now that the volt is available, it's very easy to convert any straight suction canister in to a power nozzle canister, much better than going the turbo nozzle route. What a canister offers over an upright can be described in two words, flexibility and versatility.

 

[sptyks]

Well N0oxy, that's a matter of opinion. I happen to find an Upright much easier to just grab and start cleaning my carpets with out setting up a canister by connecting the hose etc. I also find it a pain in the butt to drag a canister around behind me always worrying if I might trip on it if I back up.


 


But here's the most important negative about canisters and that is deep cleaning ability.


A power nozzle is just not heavy enough to do a good deep cleaning job. You need the weight of an upright vacuum to really get down and form a proper seal with the carpet.


 


Now straight suction canisters are great to have around for above the floor cleaning.


 


I personally like a small simple inexpensive canister like the Eureka Mighty Mite as a companion to my Kirby Sentria for all my above the floor cleaning.

 

[ctvacman]

Durango

There was a bissell direct air with a hard body that had a bag full indicator light, late 90's can't remember the model. I remember it clearly though, it was plum colored with the hose going up the side of the unit and stopping at the top. Many Hoover hard bodied units had the little pop out thing but that certainly was not a indicator light.

 

[panasonicvac]

I agree with everything of what sptyks said. I really hate canisters, I take a central vacuum anyday over a canister that can be easier, lighter, and maybe wouldn't trip over as much than compare to a canister. If I want a vacuum that can do a better job on carpets and something that can also easily do above floor cleaning, I would go with a "Metal bypass upright" like a Riccar, Simplicity, Cirrus, Evolution, etc. They have a inlet port on the back to use an extension hose on and use it like you are using a central vacuum.

This picture is not mine.

 

[n0oxy]

central vacuum

Central vacuums are good, you do have the long hose but you're not pulling something behind you, and if you want the most powerful suction and airflow, connect a central vacuum hose directly to a central vacuum power unit, without pipes, the power this gives you is amazing. Another option is the backpack vacuum, although this can knock in to walls if you are cleaning a closed space, definitely lots of vacuum options out there for sure. I'm just not a fan of uprights, but that's personal preference.

 

[durango159]

NoOxy-- I disagree about the weight of a power nozzle vs. an upright.

Yes weight is important but more important than that is carpet height setting. Many power nozzle canisters have height settings. The majority of uprights have height settings. With a height set properly the weight of a cleaning head isn't near as much of a debate in the issue. Not all power heads and uprights are created equal. Orecks, Eureka Bravo, Hoover Air series, Sharks, Dyson, many uprights on the market over time are very lightweight heads. Power head wise: Miele SEB217, current Filter Queen Majestic, Riccar Snap/ mid size power head and many others are compact, low weight power nozzles with no height settings. They each do OK at cleaning but nothing substantial. A substantial power nozzle would be an Aerus, Hoover Quadraflex, Hoover Windtunnel, Simplicity Verve- full size, Beam Rugmaster, Kenmore Progressive, etc. Those are good cleaning power heads!!

Otherwise as you describe it, a Kirby head may have weight but if height adjuster is set wrong then the weight means nothing at all. Also Kirbys and other uprights are quite rear heavy compared to the front of the housing.

As long as a power nozzle on a canister is set properly to the carpet with suction set properly and it's a decent nozzle with good balance and manueverability such as this Simplicity Verve power nozzle then a good seal to the rug is easily acheived!! The suction of the vacuum pulls the carpet to the vacuum head creating a good seal while the airflow and agitation go to work at removing the dirt.

As far as tripping while using a canister. I've tripped with chairs and small book racks that I have moved out of the way to do my vacuuming but I have not tripped on a suction unit. I reverse my way out of a room and guide the canister back with my foot. Maybe I've just gotten quite used to it. I would just much rather manuever a power nozzle that can get under chairs, coffee tables, night tables, and beds.

A main reason I like canisters is that the wand is 1.25" thick respectively. I'm manuevering a very thin wand around a room which is lighter to use and easier to steer and see around without rubbing into things compared to a 15" thick upright body squeezing between various furnishings!! I don't want a vacuum bag compartment rubbing against my bed blankets or possible scraping along window sills while cleaning!!

 

[tolivac]

I am generally an upright guy as well-Kirbys,Tacony Tandem air,Royal metal,and Sanitare uprights my main choices.Canisters are great for other jobs-and a great choice if you don't have carpet.I have WW carpet-so the upright is still best for that job-really easier-just grab and go.Uprights can win in carpet cleaning-remember their high CFM and fan close to the floor?I use my canisters-central included for other vacuum jobs-except when pairing the Kirby with my MD central as a powerful tandem air machine.Tacony tandem air vacuums do have bag filled indicators.for it to show the bag has to be packed pretty tight-these and good at packing their bags.The bags in the Tacony tandem air machines may look small-but they are well packed!The combination of direct air and clean air design packs the bags tightly!

 

[n0oxy]

weight of power nozzles

Actually, I think it was sptyks's post that you are disagreeing with rather than mine. Like you, I'm a big fan of canisters like we talked about at the convention a few months ago. It was interesting hearing the tones of the different Hoover canisters at the museum.

 

[n0oxy]

swapping hoover power nozzles

Rob, I know you're a big fan of the Hoover power nozzle canisters, just curious, have you tried using a different hoover power nozzle than the one that came with each canister? I think you said you have 11 different Hoover power nozzle canisters, does each canister have a different power nozzle or are some the same? I guess it may not even be possible to do this, depending on if the hoses and wands are similar. I think it's kind of interesting to pair canister vacuums with other power nozzles than what they come with, for example, using a Riccar power nozzle with an Electrolux canister, or a Sebo power nozzle with a Panasonic. If a power nozzle has a pig tail cord, this is really easy to do, the nozzles that use direct connect are a bit more difficult, but can still be done if you make a pigtail cord with the right connectors.

 

[n0oxy]

weight of cleaning head

While uprights might be heavier, this also makes them harder to move I think. If a powernozzle's brush is at the right height, it should be able to clean as good as an upright. It's interesting that the volt cleans so well since it does not have a height adjustment setting.

 

[sptyks]

It all boils down to Airflow! The Bypass design of the canister does not supply enough airflow to pull the carpet up to the nozzle to form a complete seal to the carpet. And it is true that direct air uprights require a little more effort to push because of this, but that is why Kirby developed Tech Drive which reduces the effort to push the vacuum by 90%. The kirby G series vacuums can be pushed and pulled with only two fingers with Tech Drive engaged.

 

[anontemp123]

I have read this thread again and again, and I think I have the answers to all my questions. Thank you so much.

As far as filtering the motor cooling air in direct air vacuums: Why can't this air just be sent up to the bag with the dirt and filtered that way? I actually assumed this was the case, but now it makes sense why 'bypass' is said to have better filtration. I know for allergy sufferers this can be a huge deal. I was looking for used Riccars on Craiglist and asked a seller why she was selling her Riccar Vibrance. She replied her family members required even better filtration than a Riccar bypass. She ended up having to purchase a top-of-the-line Rainbow.

 

[anontemp123]

And where could I find an explanations on the importance of suction? I've read and seen so many explanations on the importance of airflow, but nothing that gives suction the spotlight. After all, suction does still matter. Sort of like an idiot's guide to understanding static pressure. How is suction generated. Etc.

 

[n0oxy]

suction and airflow

Suction is the actual pressure difference that is created, if you put your hand up to a hose and it grabs on really hard, than there is a lot of suction. Airflow is how much air is being moved. You actually need a decent amount of both to clean well. And, the more you have of one, the less you will have of the other. The clean air uprights generate a lot of airflow but not as much suction which is why they don't work as well with attachments. On the other hand, if you have very strong suction but don't move as much air, the dirt will not move towards the nozzle so the vacuum can pull it in. Again, you need a decent amount of both to clean well.

 

[n0oxy]

the tandom air concept

I know many think that the dirty air design actually cleans carpets the best, I do think that a good power nozzle canister will clean just as well as an upright though. Still, the tandom air uprights that Tacony produces do seem to do a really good job at cleaning carpets. And of course there is the volt power nozzle, really this gives you the best of both worlds if you hook it up to a canister, backpack or central vacuum. You have the high airflow of the dirty air design, but you also have the extra suction or lift provided by the canister motor, the only thing that concerns me about the dirty air design is that everything picked up goes through the fan. I know fans have improved to prevent breaking, but I would think after a while, dust would become caked on the fan blades in this design.

 

[anontemp123]

Let's take it one step back. For me it's easy to understand airflow. Fan moves, generates airflow. Bends reduce airflow.

However, what is generating suction? Is it also the fan? Some other part of the design? I have a notion that for suction, it doesn't matter how long the path is, or how many bends you have, suction remains constant. Does that sound right?

 

[kirbysthebest]

Suction: the production of a partial vacuum by the removal of air in order to force fluid into a vacant space or procure adhesion.


Hence, the fan pushes air away, and the atmospheric pressure forces air or fluid (air is actually a gaseous fluid ) into that space.  Remembering that nature abhors a vacuum. 


 


 Suction as we would define it is created in a vacuum cleaner  by placing a restriction between the fan casing and the nozzle or hose.  Where through the Beurnoulli Principal there is a low side and a high side.  The speed of the air increases through the restriction and thus we have a vacuum cleaner, or a suction sweeper.  Basically air traveling from atmospheric pressure, speeds up through the restriction to fill the vacuum created by the fan and then returning to atmosphere.


 


Air flow would be the speed in which the air is moving, and suction would be the force in which it is being removed.

 

[n0oxy]

creating suction

In order to create suction, you need at least somewhat of a seal, if everything is totally sealed, you then have maximum suction but no air flow at all which is not very useful. To see the difference a seal makes, if you have access to a canister vacuum, open the bag compartment and turn it on. You will probably feel lots of air flowing but not a lot of force, in this state, nothing is really sealed, so you have a large amount of air but it's not moving with much force. Again, to clean well, you need a decent amount of both suction and airflow. This also gets in to the difference more than one fan stage can make. If you have more than one fan in series, it increases the suction, on the other hand, if you have fans in parallel, the airflow is increased. Airflow will also be restricted by things such as the hose diameter, that's why in applications such as central vacuums works best with a wide diameter hose. I'm actually thinking of trying a commercial 1.5 inch hose on my central vacuum units to see how it works.

 

[sptyks]

Suction vs Airflow and Filtration

Harley and Mike, you gave excellent definitions and descriptions of Suction vs Airflow in the previous posts.


 


I have another description of these two forces. First off, always remember that as one increases, the other decreases. However as stated earlier, you do need both to clean a carpet.


 


I own several Kirby's which are Direct Air or Dirty air machines. The Kirby has a huge amount of Airflow at 127 -130 CFM (cubic feet per minute) but low suction measured at 32 inches of water. This is because the opening to the fan chamber is a full 2 inches in diameter allowing all that air to move very quickly through the machine.


 


I also own a Hoover WindTunnel Air vacuum which is a bypass air bagless vacuum. In contrast to the Kirby, the Hoover has lots of suction but much less airflow because the diameter of the hose and internal piping is a narrow 1 1/4 inches. The Hoover has only 60 CFM airflow but the suction measures at 80 inches of water.


 


So therefore assuming the size of the motor and type of fan is the same, it is mainly the diameter of the opening which the air passes through that determines the amount of suction and airflow.


 


Now lets talk about how the length of the hose or internal piping affects suction and airflow. So the LONGER the hose, the less suction and airflow you will have. This is why Central vacuums typically located in a basement or garage have very powerful 240 volt motors. These huge motors are needed to overcome the loss of suction and airflow caused by the very long internal piping that is located inside the walls of a home. These pipes can be 50 to 150 feet long depending on the size of the house.


 


As far as filtration goes, the difference between Direct Air and Bypass Air vacuums is insignificant. Both can have synthetic cloth HEPA bags which filter the air down to particles of less than a Micron which is excellent. The fact that Direct Air vacuums use a separate fan to cool the motor does not really affect their ability to filter well. The exhaust air coming from the cooling fan contains only a few microns of carbon coming from the motor's carbon brushes. As far as I know no one is allergic to carbon because our bodies are made up largely of carbon.


 


The Kirby is a Direct Air machine which has the Gold Seal of Approval from CRI (Carpet and Rug Institute.) To get a Gold Seal, CRI measures these two things: the amount of dirt removed from several different types of carpet and the quality of air exiting the machine (filtration). If you are not familiar with CRI here is a link so you can check any make and model vacuum. The first link is CRI testing standards. The second link is a list of certified vacuum cleaners and their ranking.


 


http://www.carpet-rug.org/vacuums.html

 


http://www.carpet-rug.org/certified-vacuums.html

 


 


 


 


 


 

 

[Mike81]

What is good airflow rating?
One very powerful canister is Philips Performer Pro bagged canister vacuum. It has 108 cfm and 500 airwatts of suction/airflow. Something that is excellent for canister vacuum. It is measured from the hose end by the consumer reports.
This 2100 watt vacuum is now discontinued due to the too high wattage motor. For US people it is 18 amps.
I bet that Kirby or Royal will produce more cfm, but for canister TRUE 108 cfm seems very good.
My parents have that Philips now (my ex vacuum). It has powerhead outlet, so I might test it with the full-size Wessel Werk powerhead.
And what it comes to canister vs upright, I personally like both.

 

[sptyks]

Mike81,


108 CFM is excellent for a canister vacuum.


 The Kirby Avalir has close to 130 CFM and the Royal 8300 has close to 150 CFM but those are both Direct Air upright vacuums.


 


You can still use the canister with 2100 watt motor in Finland correct?


This canister would be illegal in the US. Our maximum wattage for vacuums is 1440 watts or 12 amps.


 


 

 

[Mike81]

Well 18 amps / 2200 watts is now illegal in EU because of new regulations. It is only that stores can't sell those high wattage vacuums. Of course we can keep them.
Only vacuum that comes close to it is the last high wattage Electrolux Ultraone with 465 airwats.
One note is that Philips uses large diameter hose. Also Electrolux has fairly large diameter hose.
These vacuums has very straight airpath to keep the good airfow.

 

[anontemp123]

Ok, so the length of the hose *does* affect suction? I thought as long as the system is sealed, suction should not be affected by the hose length. Another hurdle for me is to understand why, even with a dirty filter, I don't get loss of suction with my current bypass. Is it the nature of suction, or something to do with Dyson's cyclone system.

I found these videos useful: (second one was the best)



(I tried to make the videos a link, but I couldn't figure it out. The messageboard software embeds them like this.)

Although, in this one, can you really just add the two figures like that?

 

[tolivac]

I have not heard of any "regs" prohibiting vacuums in the US over 1400W.If the vac draws more than this it would have to be equipped with a 20A 120V NEMA plug.-Like any other 20A device.I have a Blendtec "Titan" blender that has a 20A motor-what is on the blender nameplate-it has a NEMA 20A plug.Many central vacuum units draw 15A @ 120V.1800W.Have such a unit.Then there are the 240V central units that would need a NEMA 15A or 20A 240V plug and outlet.Many shop tools like table saws have this,too.Know a friend that has a woodshop in his garage and his 7Hp planer runs from a 60A 240V "stove" outlet.

 

[n0oxy]

decreases of suction and airflow

In theory at least, as the pipe runs get longer and there are more twists and turns, the airflow will decrease, but the pressure difference would stay the same, assuming that the system is sealed well. There are some central vacuum units that have two motors, if the motors are in series, you will increase the pressure difference, however if the motors are in parallel, you will increase airflow, but remember that airflow is also restricted by a narrow path, so if the maximum amount of air is already flowing through a hose, adding another motor will not increase the performance unless the hose is wider. This is why on some canister vacuums such as the Sebo, the hose becomes wider as you move towards the end that connects to the vacuum itself. The most powerful central vacuum unit I have in my apartment is the Purvac Barracuda, it has 144CFM and 151 of suction, and connecting a central vacuum hose directly to it, or any central vacuum unit is really awesome, like a super powerful canister vacuum. I have several central vacuum units throughout my apartment, a total of 7 of them. In the United States, the maximum power an appliance is allowed to pull is 12 amps, that's for a standard 120 volt outlet, I do think some central vacuum units actually draw more though. In Europe, they use a 220-240 volt system, and if you have higher voltage, the motors will draw less amperage. If I had a 220 volt outlet, I would consider getting a 220 volt unit, they are quite powerful. Hmmmm, all this talk about central vacuum units has made me want to connect the hose and fire up a few of them, so I'm going to go do that.

 

[n0oxy]

more airflow with open bags

So, as I stated in my last post, I did fire up a couple of my central vacuums, and then I pulled out my sanitaire backpack vacuum. Backpacks are interesting because the bags they can use are a bit different from most canister and upright bags. This backpack came with a paper bag, the first thing I did was to replace that with a cloth bag, many backpacks can use the same bags, and 10 quart cloth bags are easy to find. I tried running the vacuum without the lid on, quite a bit of airflow, it almost felt like a regular table fan, but of course, you really could not clean with that, there was no seal, the air was allowed to flow freely. Once you put the lid back on, it creates a semi-seal, and that's where you get your suction. For backpacks, you can choose to use closed or open bags, apparently the main advantage of open bags is that you can dump them out and reuse them. I would never reuse any bag, even if you dump out everything that is visible, dust will still clog the pores of the bag. The main reason I use the open bags in my backpacks is because they allow more airflow through the bag. Interestingly, the central vacuums made by MD manufacturing also use this approach for their bags, the bag goes in to the top of the unit and provides a lot of surface area for air to flow. Since the Kirby vacuums have so much airflow, I'm wondering if the bags they use are similar to this, or do they use the close bags like what you see on most canisters, where the only opening is for the tube to be inserted.

 

[sptyks]

Kirby and Royal airflow

N0oxy,


The Kirby and Royal bags have only one opening near the top of the bag. The large volume of airflow is because the bags are quite large so there is a lot of surface area for the air to pass through. The full line is only halfway up the bag so the top half of the bag remains empty so that dirt does not block the pores in that part of the bag. The outer bag on the Kirby and Royal also allows air to pass through and acts as a secondary filter. This is quite different than canister vacuums and some other upright vacuums where the bag is totally enclosed inside a solid enclosure further restricting airflow.