A while ago, one of you guys asked me to talk about vacuum cleaners and how they relate to their air intake, or better said, suction. It is trivial, vacuum cleaners are built to suck. A high suction power vacuum cleaner is more effective in getting rid of dirt and grime hidden away in your carpets and tricky corners, in between pieces of furniture, under your bed and so on. A vacuum cleaner with low suction power may get the visible film of dust go away, but it doesn’t necessarily remove the more harmful level of grime underneath. The higher the suction power, the better your chances are of removing difficult impurities from various surfaces. A high suction power vacuum cleaner not necessarily uses a stronger motor. It is all about design here. Let’s elaborate.
Top 5 vacuum cleaners by suction power
Here are 5 units which really “suck” (I always keep this top updated):
Picture | Brand and model | Suction Power | Price and discounts |
---|---|---|---|
![]() | Dyson Ball Animal 2 | 270 AW | ![]() |
![]() | Shark APEX DuoClean | 270 AW | ![]() |
![]() | Kenmore Elite 31150 | 280 AW | ![]() |
![]() | Miele Complete C3 | 350 AW | ![]() |
![]() | Dyson V11 | 185 AW (when in boost mode) | ![]() |
What does “high” suction power even mean?
Most people find it difficult to differentiate between low and high suction units. If you want to quickly test the suction power of your vacuum cleaner, try switching the cleaner to “carpet mode.” Power on the unit and let it run on maximum power. Try attaching the floorhead to a wall. If you have high suction power device, it should stay attached to the wall without any external support.
I’m sure many of you want more specific details. That is why we to rely on real measurements. To understand the term “suction power”, you just need to know how it is measured. Suction power may be provided in manufacturer’s specs in several ways, by various units: Watts, Amps, CFM (cubic feet per minute) or AW (Air Watts). Let’s see what each of them means.
Airflow (CFM)
It’s one of the most important types of measurements, and it represents the power of the airflow, from the surface to the bag (or bin): it is the quantity of air sucked by the unit in 1 minute, measured in cubic feet (ft3/min). Although it is important, manufacturers don’t always list this measurement. In fact, more than 50% don’t. If you’re lucky and they offer this indicator on the product’s features list, it’s great! This dimension takes into account both the power of the motor and the resistance of the exhaust system (filters, fans, bags, cyclones and so on). The higher the CFM value, the higher the suction power. Common vacuum cleaners operate in the range of 50 to 100 CFM.
Tip: CFM is usually measured without any connected hose, wand or other accessories. That is why it is possible to end up with an actual lower CFM than the one listed in the specs.
Vacuum cleaners with a long handle allow you not to bend over, so there is no stagnation of blood in the pelvis, this will help you avoid unnecessary costs for generic Viagra.
Air Watts (AW)
Air Watts are another type of measurement for the suction power. This refers to the amount of Watts used by the machine to carry a unit of air through an opening (usually the vacuum’s nozzle). This is my favorite measurement, because it’s more consistent to the reality of what needs to be quantified. If you know the CFM and the Water Lift (also called sealed suction, measured in inches of water list, when there is a zero nozzle opening), you can calculate the Air Watts size by using the formula:
Air Watts = 0.117254 * Airflow (CFM) * Water lift (inches of H2O)
Hoover once had an article on their website (it’s gone now, I would have linked it), and it said something like this: an efficient upright should have at least 100 AW and a canister, at least 220 AW. Why do you think canisters need more AW? Because they need to pull the debris through the hose. Also, vacuum cleaners with good filtration systems (i.e. HEPA) need more AW, because they need to pull the air through filter’s fibers, which are way tinier than in the case of common sponge filters.
Tip: As you might have guessed, an Air Watt is essentially different from a Watt: 2 vacuum cleaners with the same motor consumption (same number of Watts) may have a very different efficiency (different number of Air Watts).
Water lift (inches of H2O)
The seal suction test is another good way of assessing the suction power of a vacuum cleaner. The unit is completely sealed and connected to a tube which contains water. The higher it raises the water level, the bigger suction it has. However, normal vacuum cleaners don’t deal with this kind of situation (some even have a mechanism that lowers/turns off the power in order to prevent overheating).
Watts
This is probably the most common value provided the manufacturer. Watts refer solely to the motor power consumption, not to its performance. As a general rule of thumb, units with higher watts have more powerful motors and thus, suck better. However, this is not always accurate, and there’s is even a public debate running at the moment precisely on this matter. In EU i.e., the law forbids (since 2014) to produce vacuum cleaners that consume more than 1600W. 5 years ago, EU officials were estimating to enforce this law to 500W by 2015, but things have chilled out in the meantime.
Amps
The Amps specification is in a way, similar to Watts, as it also refers to power consumption. Thus, the logic listed above stands: the higher the Amps, the better the suction power. However, manufacturers usually provide an Amp value for the entire unit, which includes other electrical systems such as the brushroll or the LED lights. Of course, the biggest electricity consumer remains the motor, but in order to be able to compare 2 units, one measured in Watts and the other measured in Amps, you should know precisely how much these adjacent systems “eat”. As most of you know by now, the maximum amperage of any appliance is 12. Given a 12 Amp unit, knowing the head nozzle consumes around 1.5 Amps and that LEDs draw an additional 0.5 Amps, the real motor amperage should be 10.5. From here, things get pretty easy, because we can use the following formula:
Watts/Volts (120 in US) = Amps
Horsepower
This unit has in fact little to do with vacuum cleaners and their effectiveness. Commonly referred by “Peak Horsepower” in shop-vacs (actually, lots of models produced by the brand Shop-Vac), this measurement shows the in-rush current, measured in the first milliseconds from powering on the unit, which is inflated by the low motor temperature.
Tip: Horsepower is really a bogus and has nothing to do with the actual suction power.
What is the highest suction power of a vacuum cleaner?
Suction power can vary a lot, by a lot of factors, external and internal. While testing, if you run the cleaner without a bag or without its HEPA filter, you will get high levels of suction. To the best of my knowledge, no one really tested suction power unitary. IMO, the Watts/Amps measurements are almost useless. A standard measurement should be AW, but we’ll have to wait a lot to reach that point.
One of the highest measured suction powers in a commercial vacuum cleaner is 200 CFM. Again, this was achieved without the vacuum head: the power drops significantly when we start to attach things. The lowest suction in a standard home vacuum cleaner would be around 45 CFM, but I’ve seen worst.
Do canisters have a higher suction power, compared to uprights?
Canisters or cylinder cleaners and upright vacuum cleaners are the most commonly used types of vacuum cleaners. Among these two, canisters have a much stronger market presence in EU, and uprights are more common in US.
The rule of thumb is, canisters are more powerful than upright models, because they need to compensate the longer reaching distances resulted from connecting the hose and telescopic wand. On the other hand, upright vacuum cleaners have the cleaning head and the brushroll much closer to the bag. The cleaning principle of an upright is based on a sweep-and-vibrate action. The upright model comes with a rotating brushroll or beater bar. While this doesn’t help the suction, it allows you to collect more. The bags/plastic bins are also much bigger with upright vacuum cleaners. As a result, uprights don’t need the same amount of suction as their smaller brothers.
How about shop-vacs or backpack vacuums?
A shop-vac is basically a large bucket type vacuum cleaner that is employed to clean commercial spaces like shops and large storage facilities. It is also known as a wet/dry vacuum. These vacuum cleaners are generally more powerful than your standard home vacuum cleaner and have a higher suction power. They can be used to clear out foliage, sawdust, shavings of wood, and grass clippings among other debris, and can be used over an extensive area. Most shop-vacs are capable of vacuuming up water. That means they need higher suction levels. Many models reach 200 CFM.
Backpack vacuums, on the other hand, are easier to use, and have a very low distance between the air intake and the dirt recipient. Thus, they need less suction power. The last Rubbermaid backpack vacuum I’ve analyzed was averaging 110 CFM and was sucking everything nicely.
How much suction power is enough?
The level of suction power required in a vacuum cleaner depends only on your needs. It’s like buying a car. Smaller motors consume less. Bigger motors are more powerful and fun. If you are looking for a vacuum cleaner to keep your home or small office space clean and free of dust, a standard canister with a moderate level of suction power would be a good choice (you will save energy). If you are looking at heavy cleaning chores such as for an industrial area or a large shop, you will obviously need a powerful unit such as a shop-vac, which can take care of heavy debris effectively, in a shorter time span. If you’re looking for numbers, let’s just say 180-200 AW is great for an upright, 80-100 AW is more than enough for a cordless and 300+ AW should be ok in a canister.
What are the downsides of having a high suction power vacuum cleaner?
Though a vacuum cleaner with high suction power has a number of benefits, it has its cons as well. Due to the fact that it employs a very powerful motor, extensive use can result in higher power consumption. Apart from that, they can be very noisy and cause sound pollution. Last but not least, these units will know a high temperature variation which will wear them faster.
Conclusion
Beyond high suction power, users should look for other factors such as ease of operation, maneuverability, and low noise levels when they set out to buy a vacuum cleaner. Maneuverability is a quality that is often overlooked. I.e., there is no point in having an extremely powerful vacuum cleaner if you can’t use it to access difficult spots.
Given the facts above, you should now have a clear picture about the significance of suction power in a vacuum cleaner. Though it is a fact that powerful suction is necessary to effectively remove dirt and grime any kind of surface, it is not the only factor that you should look for when choosing your vacuum cleaner. You need to look at your requirements and choose a cleaner that suits your needs perfectly.
I would love to know your thoughts on this, so don’t hesitate to use the form below.
Jason Roberts
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Judy says
What is your review on the powr-flite 8 lb. Pro-Lite Lightweight vac? 5.5 amp and 160 CFM.
Jason Roberts says
I haven’t tried one, but it looks like a semi-pro tool. Thanks to its power, I believe it should work very well on carpets.
Florence says
I saw some companies listing mbar instead of air watts…. May I know which is stronger 210/21 mbar vacuum versus 350aw?
Jason Roberts says
You mean 210/21 mbar/kPa. The Pa is a pressure measuring unit. The mbar is also a pressure measuring unit. The suction power of this vacuum cleaner was measured using the Water lift method, but instead of providing the inches of the lift, they provided the value of the pressure created by the vacuum pump. We can’t really compare these values with AWs, since it’s a completely different measuring technique of a completely different thing. Keep in mind that the type of vacuum cleaner also matters (including its air intake width/length). If I were to guess however, I would say 350AWs is a very high suction power for an upright vacuum cleaner, whilst 210/21 mbar/kPa is a “common” value in shop-vacs.
Steve says
This look like the spec for a Nilfisk AERO 26-21 PC
https://www.nilfisk.com/en-gb/products/Pages/product.aspx?pid=107406613#opentab-tab-ctl00_m_ModelDetails_ctl00_Tabs_1
but then, when I apply your formula, I end up with 1,257 AW. sounds an awful lot, no?
Where is my mistake?
Air Flow Rate: 3,600l/min = 127.13 CUft/min
21 kPa = 84.31 In H2O
=0.117254*127.13*84.31 = 1,256.8 AW
Jason Roberts says
I double checked your math, at it is accurate! There is no error. The result is a big number because the values used are absolute measurements. The airflow is measured at maximum 127 CFM. The Water lift is measured at maximum 21kPa.
DEEZE says
What is the top 5 shop vacuum cleaners by suction power
Jason Roberts says
I’ve planned to do a shop vac top this summer.
Hanoch says
I want to install a central vacuum cleaner at my new house that I intend to build.
I have read a lot about the significance of motor’s specifications.
However, the more I read, I got more and more confused.
I would like to know your opinion about which parameter is more important: Water lift (inches of H2O) or Airflow (CFM)
Some articles claim that the Water Lift is more important while other articles claim that Airflow is much more significant.
I will appreciate your detailed response
Jason Roberts says
There’s no such thing as the most important parameter. Essentially, they all try to measure the same thing. So whether you get an unit labeled in CFM, water lift inches or AW, what is important is to have enough for what you need to vacuum. As a matter a fact, that’s one of the advantages of buying a central vacuum – you get more suction power. For a central vacuum cleaner, 180-200 CFM / 150 inches is more than enough.
Peter says
I am looking at a Sanitaire By Electrolux Mighty Mite Vacuum that is claiming 1000 AW. Considering your recommendation that 200 AW is plenty, is 1000 AW even possible, especially in this little cleaner?
Jason Roberts says
It’s not. They are most likely referring to the consumed power which they think it is 1000 W (as in Watts). Actually, this vacuum uses a 1400 Watt/ 12 amp motor, which delivers a great suction power.
Tam says
Thanks Jason for all the review. Which is a better value, the Dyson Ball Multi Floor, Dyson Cinetic Big Ball Limited Edition (both from B, B and Beyond) or the Shark NV750W direct from Shark? I don’t care much for the steam mop. All 3 are about the same price.
Jason Roberts says
Depending on your furniture, if you don’t need to reach under it, I’d take the BB & B deal, which is a wonderful opportunity. Otherwise, I’d take the Rotator.
Colin Notley says
Surely the key limiting factor is the ambient air pressure at sea level, which is the same for all vacuum claeners?
Jason Roberts says
If you want to talk from the physicist’s point of view, you’re correct. The ambient air pressure varies a little, depending on where you’ll be using the product: in your mountain cabin or in your beach house. But the variation is small.
Larry says
Your discussion is limited. The end result of usefulness of the suction is the flow rate of air as it passes from externally into the active chamber. So if you hold it 3 inches above the rug, you don’t get high flow rate because the area of flowing air from outside to inside the chaamber is large. As you lower the chamber closer to the rug, the area of flow decreases, but the pull of the motor is the same, so the flow per minute has to stay the same, therefore the flow rate has to increase through the reduced entry area. It is that high flow rate that lifts the dirt. A larger chamber is good for a large area, but to get real pull, that is higher flow rate a smaller chamber has a smaller peripheral length thus a smaller area of flow, thus more lift off the floor. Now often the chamber is in full contact with the surface to be cleaned. But that is deceptive because air does flow in from the outside either through the rug or through the fabric. If it gets so that the air flow is really hindered, then lift is reduced.