What Is a Good Suction Power for Vacuum Cleaner?

Published 28 November 2025. Last updated 9 September 2026.

For hard floors you need less suction than the marketing suggests, and for carpet you need more. But no published standard sets a Pascal threshold for either, and manufacturers measure Pascals under their own conditions, so the figure is a rough guide to capability rather than a prediction of how clean your floors will be.

Suction is the number every brand puts on the box, MOVA included. It is also the number most often misunderstood, because a Pascal measures one specific thing and people read it as though it measured cleaning.

This page explains what a Pascal actually is, how it converts to the other units you will run into, why two machines quoting the same figure can clean differently, and how to read a suction claim without being sold to. Including ours.

How much suction do you actually need?

It depends on what is under your feet, and the honest answer comes as ranges with reasoning rather than precise thresholds, because nobody publishes precise thresholds.

• Hard floors: modest suction is enough. Dust and grit sit on top of tile, LVT, laminate and wood, so airflow alone lifts most of it. Very high suction on a hard floor mostly costs you battery and noise.
• Low pile carpet: moderate suction. Debris sits shallowly and a roller reaches it, so this is comfortable territory for most machines.
• Medium pile carpet: more suction genuinely helps. Grit falls between the fibres and has to be pulled against their grip.
• Deep pile and pet homes: the top of the range earns its money here. Hair and grit trodden into deep pile need both strong pull and real agitation.

Notice what those ranges do not contain: numbers. That is deliberate. Any guide telling you exactly how many Pascals a medium-pile carpet requires has invented the figure, because no testing body publishes one.

How is vacuum suction measured?

A Pascal is a unit of pressure, so a suction figure in Pa describes how much negative pressure the machine can generate with its inlet sealed. It is a real measurement, taken in controlled conditions by the manufacturer.

What it is not is a measure of cleaning performance. The international method for that, IEC 60312-1, sets out how vacuum cleaner performance for household use should be determined, and it is a different exercise altogether from quoting a peak pressure figure. Dust removal is tested against defined surfaces and materials, not inferred from pressure.

That gap is the single most useful thing to understand about suction claims. A brand quoting a high Pa figure is telling you something true about its motor and seal. It is not telling you how much dust ends up in the bin.

What a Pascal does not tell you

Cleaning happens where three things meet: pressure, airflow and agitation.

Pressure is the Pascal figure, and it is measured with the inlet blocked. Airflow is the volume of air actually moving through the machine, and it is what carries debris away once the pressure has lifted it. The two work against each other: the moment air starts flowing, pressure drops, which is why a sealed-suction figure describes a condition that never exists while the machine is cleaning.

Agitation is the roller flexing carpet fibres open so that pressure and airflow can get at what is trapped below. On carpet it does as much work as the motor.

So two machines quoting identical Pascals can clean quite differently. One may have a wide, smooth airflow path and a rubber roller; the other a restricted duct, a leaky bin seal and stiff bristles. Same headline, different result.

The units, and how they convert

Vacuum specifications arrive in at least five units, some of them imperial. Here is what each one measures and how it relates to the others.

Two practical points fall out of that table. A machine quoting 20 kPa and one quoting 20,000Pa are quoting the same thing, which trips people up when comparing a stick vacuum with a robot. And a figure in CFM or inches of water is an imperial specification, so convert it before you compare it with anything metric.

What is the difference between Pa and air watts?

Pascals measure pressure only. Air watts combine pressure with airflow, which makes them a better single indicator of how much work the machine can do at the floor.

The physics is straightforward: air power in watts equals pressure in pascals multiplied by airflow in cubic metres per second. Where it gets slippery is that "air watts" as printed on a box is a manufacturer-derived figure rather than a single standardised measurement, so it carries the same comparability warning as Pascals do. Treat both as indications, not verdicts.

How many Pa do you need for carpet?

More than for hard floors, and how much more depends on pile depth rather than on a number anyone can give you. What matters is that the machine can pull debris against the grip of the fibres holding it, while a roller flexes those fibres open.

Pile construction changes the job. The Carpet Foundation describes twist pile as having "a coarse, rugged finish", which is a relatively firm surface that a roller can work. It notes that Saxony "has a deep pile with a pronounced sensuous feel" and does flatten, and that is where suction and agitation both start to matter far more.

So the useful question is not how many Pascals, but whether the machine has enough pull and the right roller for the deepest carpet in your house. Our guide to robot vacuums for carpet works through the pile types properly.

Is higher Pa always better?

No, and this is where most suction content misleads people. Beyond the point where a machine comfortably lifts what your floors hold, extra pressure buys you diminishing returns and costs you battery life and noise.

On a hard floor in particular, more suction rarely produces a visibly better result. It runs the motor harder, drains the battery faster and makes the machine louder, which is why carpet detection exists: the sensible design applies maximum power only where the surface demands it.

Noise is worth a word here too. Moving more air makes more sound, and household appliance noise has its own measurement standard, IEC 60704-2-1, which covers how dry vacuum cleaner noise should be determined. High suction and quiet operation pull against each other, so a machine you run in a lower mode most of the time is often the better daily companion.

The four things that decide how well it cleans

Suction is one variable of four, and the other three rarely appear on the front of the box.

Brush design

The roller does the agitating. Stiff bristles flick grit out of carpet well but hold onto hair, and a roller wrapped in hair drags against its own housing and loses effectiveness. Rubber rollers flex instead, so hair rides into the airflow rather than winding round the shaft. On a pet home that difference outweighs a few thousand Pascals.

The airflow path

Air has to travel from the nozzle, through the duct, into the bin and out through the filter. Every sharp bend and narrow section costs airflow, and airflow is what actually carries debris. A well-designed path with a mediocre motor can outperform a powerful motor breathing through a restriction.

The bin seal

Suction only reaches the floor if the whole path is sealed. A poorly seated bin, a perished gasket or a badly closed lid lets air in somewhere other than the nozzle, and the pressure figure on the box becomes irrelevant. This is also why a machine feels weaker over time when nothing is technically broken.

Filtration

The filter is the last thing the air passes through, and it is the commonest cause of lost suction in a working machine. Fine dust mats across the pleats, airflow drops, and the machine feels broken when it is simply blocked.

Filtration also determines what stays captured. Allergy UK notes that pet allergy is driven mainly by dander rather than visible hair, and its guidance recommends cleaning carpets with a vacuum fitted with a HEPA filter. In Europe, HEPA is a graded classification rather than a single specification, so a filter described only as HEPA with no class stated is not telling you much. Our guide to robot vacuums for pet hair covers this in more detail.

How to read a suction claim, including ours

Four rules will keep you from being misled by any brand's specification sheet.

• Compare within a range, not across brands. Two models from the same manufacturer are measured the same way, so the difference between them means something. Two figures from different manufacturers are not necessarily comparable at all.
• Treat the figure as a maximum, not a working level. It is a peak in a sealed condition. The machine will not run there for most of a clean, and you would not want it to.
• Small gaps mean little. A difference of one or two thousand Pascals between brands is inside the noise of different test conditions. A gap of ten thousand tells you something about design intent.
• Look for the other three variables. Roller type, dock and bin design, and filter class tell you more about long-term performance than the headline does.

Applied to MOVA, that means our own figures should be read the same way. They are measured by us, under our conditions, so use them to rank our models against each other rather than as a trump card against another brand's number.

What is a good Pa for a robot vacuum?

Enough for your deepest floor and no more than that. Across MOVA's UK range the ladder is straightforward, and the right answer is the one that matches your house rather than the biggest figure.

The E40 Ultra at 19,000Pa is enough machine for a home that is mostly hard floor with low pile rugs, and that covers a great many British flats and modern houses.

The V50 Ultra Complete at 24,000Pa suits the more common British mix of carpeted rooms and hard-floored kitchen and hall, where you want headroom for the carpet without paying for the top of the range.

The Z60 Ultra Roller Complete at 28,000Pa is for deep pile and heavy shedding, where the extra pull and its roller system both do real work.

Who should not buy on suction alone

If your floors are hard throughout, buying the highest figure in the range is money spent on capability you will never call on, and you will run it in a lower mode anyway.

If your problem is stains rather than dry soil, no suction figure helps, because vacuuming does not extract. And if your problem is hair wrapping the roller, brush design will fix it where more Pascals will not. Our guide to choosing a robot vacuum covers what to weigh alongside suction.

Frequently asked questions

What does Pa mean on a vacuum cleaner?

Pa stands for pascal, the unit of pressure. A suction figure in Pa describes the negative pressure a machine can generate with its inlet sealed. It is a genuine measurement, but it describes pressure in a sealed condition rather than how much dust the machine removes in normal use.

Is 20,000Pa good suction?

It is a strong figure for a robot vacuum and ample for most British homes, including carpeted rooms. Whether it cleans better than a lower-rated machine depends on roller design, airflow path, bin seal and filtration, and on whether the two figures were measured the same way.

How many Pa do I need for pet hair?

Enough for the carpet the hair is sitting in, but roller design matters more. Hair that wraps a bristle brush bar reduces pickup week by week regardless of suction, so an anti-tangle rubber roller is the more useful feature for a shedding household.

Can suction power decrease over time?

Yes, and almost always for a fixable reason. A matted filter, a full bin, a hair-wrapped roller or a poorly seated bin seal all cost you airflow, and airflow is what carries debris. Rinse filters regularly, clear the roller, and check the bin is seated properly.

Why does my vacuum feel weaker than the number suggests?

Because the number is a sealed peak, not a working level. In normal use pressure drops as soon as air flows, and the machine spends most of a clean in a lower mode. A blockage anywhere in the air path will make the difference more noticeable.

Are air watts a better measure than Pascals?

They are closer to useful work, since air watts combine pressure with airflow rather than reporting pressure alone. Air power in watts equals pressure in pascals multiplied by airflow in cubic metres per second. But it is still a manufacturer-derived figure, so compare within a brand rather than across brands.

Where to start

Work out your deepest floor first, then pick the machine that comfortably covers it. Suction matters, but it is one of four variables, and the roller you can see is often a better predictor of how a machine will perform in a year than the figure on the box.

Every model in the range, with its published suction figure and full specifications, is in our robot vacuum collection.