For cordless vacuum cleaners, 150 AW (Air Watts) or more is sufficient for a primary vacuum, and around 100 AW for a supplementary one — the problem is that the same performance is labeled three different ways: W, AW, and Pa. According to a government survey reported by ZDNet Korea, only 3 of the 10 test products actually met their stated suction power, and 6 were displaying pascal (Pa), a pressure unit, as though it were suction power. In a market where manufacturers pick whichever unit makes the number look largest, knowing how to read the unit is how you choose the product.
Why 48,000 Pa Can Be Weaker Than 150 AW
The three units measure different things. AW and W are each the product of the vacuum pressure (suction force) and the actual airflow volume passing through — the international standard IEC uses W for suction power, while the American ASTM standard uses AW. Pa, by contrast, only describes the pressure state inside the machine. Blocking the inlet completely raises the Pa reading, but if no air is flowing, no dust is drawn in.
This difference showed up directly in measurement. According to ZDNet Korea's report, the 6 Pa-labeled products advertised 18,000–48,000 Pa but their measured suction power was only 58–160 W. The number 48,000 and the number 160 represent completely different physical quantities — a size comparison between them is meaningless — yet consumers naturally perceive the larger number as more powerful. The Korean Agency for Technology and Standards stated it plans to adopt the international standard into a national standard (KS) for cordless vacuum cleaners that would allow all products to be compared in a unified unit (W).
Pa is closer to "how tightly blocked" than "how powerfully it sucks" — comparison is only valid in AW or W.
How Many AW Do You Actually Need — Back-Calculating from Power Consumption
So how many AW is enough? Looking at the benchmarks in the Nosearch buying guide, 60–90 AW is sufficient for ordinary floor dust; 100–140 AW is needed to clean corners and crevices thoroughly; and 150 AW or more is required for carpets or homes with pet hair. 150 AW or above is the recommended baseline for a primary vacuum, while around 100 AW is right for a supplementary one.
If the product has no AW specification at all, you can estimate from power consumption. According to Nosearch, a cordless vacuum's suction power (AW) is typically 30–50% of its power consumption. Applying this ratio in reverse to calculate "what minimum power consumption is needed to deliver the required AW" produces the table below.
| Use case | Recommended suction (AW) | Required power consumption (W, estimated) |
|---|---|---|
| General floor dust | 60–90 | 120–300 |
| Corners and crevices | 100–140 | 200–467 |
| Carpets / pet hair | 150 or above | 300–500 |
Higher is not always better either. Boosting suction requires a more powerful motor, which means proportionally higher battery drain, more noise, and a heavier unit. Choosing a top-of-the-line 200 AW model for a home with mostly hard floors means paying in weight and price for capacity you won't use — the goal is to exceed the appropriate threshold for your floor type, not to chase the highest number.
The wide range in the estimated values reflects the fact that the coefficient (30–50%) varies with motor efficiency. The way to read it is: if a 150W product claims "powerful even on carpets," even at the highest coefficient that only calculates to 75 AW, which doesn't add up. Conversely, a 400W model yields at least 120 AW at the lowest coefficient, which is adequate for crevice cleaning. Power consumption is a figure that is difficult to inflate, making it a useful cross-check.
What to Check Alongside AW on the Spec Sheet
Once suction power clears the threshold, other usability specs make the difference. First, confirm which mode the stated suction power is based on — the peak figure used in advertising is almost always at maximum mode, so Nosearch uses as its benchmark whether the vacuum sustains around 150W even at the mid-level setting (which is what you will actually use day to day). Maximum mode drains the battery too quickly to run for more than a few minutes, and most routine cleaning is done on the mid-level setting.
By the same logic, battery life should be evaluated not at maximum mode but at whether it runs 20 minutes or more on the mid-level setting — maximum-mode runtime is typically under 10 minutes and is not a practical benchmark. For the cleaning head, whether a soft roller is included matters in Korean homes where hard floors dominate; for weight, whether the center of gravity is toward the handle (top-heavy) affects perceived effort more than the body weight alone.
The principle for not being swayed by number marketing is the same as with robot vacuums. As explained in Why Robot Vacuum Suction Numbers Alone Are Not Enough, suction power is a pass/fail threshold, not a ranking criterion — once products clear the baseline, battery life, cleaning head, and maintenance costs determine real-world satisfaction.
Who Can Buy Now, Who Can Wait
Based on published specs, the breakdown is as follows.
- Buy now — If AW or W suction power is clearly stated on the product and you can choose from those options. Once the use-case threshold and the power-consumption cross-check from the table above are both satisfied, there is no reason to wait for standardization
- Only Pa-labeled products in consideration — Pa alone cannot tell you the actual suction power, so estimate a lower bound using the power-consumption conversion before deciding
- Not in a rush — Once the Korean Agency for Technology and Standards' KS standard is applied, all products will be comparable in a unified W unit. Waiting until labeling confusion is resolved is also a valid approach
- Carpet or pet-hair households — Confirm 150 AW or more, mid-level battery runtime of at least 20 minutes, and whether a carpet-specific head (beyond just a soft roller) is included
