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Watts the difference? Consumers confused by unequal measures of suction power in robot vacuums.

Published: 05 Dec. 2025, 07:00

Robot vacuum cleaners are displayed inside an electronics store in Songpa District, southern Seoul, on Dec. 2. [YI WOO-LIM]

“Robot vacuum cleaners use pascals (Pa), not watts (W). The standard differs from cordless vacuum cleaners.”

“Chinese companies usually use pascals. If you want to know the actual suction power, watts are more accurate.”

These were the conflicting explanations offered by two salespeople stationed just 10 meters (33 feet) apart at a major electronics store in Songpa District, southern Seoul, when asked about the suction power of robot vacuum cleaners on Dec. 2.

Chinese brands prominently advertise phrases like “30,000 Pa powerful suction” next to their products. A representative of a Korean brand remarked, “That’s not the correct way to express it, but with Chinese companies promoting such big numbers, it’s difficult to properly label suction power.”

Unsurprisingly, consumers are increasingly becoming confused by the dual labeling of suction power in watts and pascals in robot vacuum cleaners.

The confusion began when Chinese manufacturers started using pascals, a unit that represents the vacuum pressure — or the difference in air pressure inside and outside the vacuum — which often yields much larger numerical values. Korean appliance companies, on the other hand, calculate watts by multiplying the vacuum pressure by the airflow volume (in liters per second) that enters the device. Industry experts note that even with high vacuum pressure, suction does not occur without airflow — meaning pascals alone cannot accurately describe suction performance.

That is why international standards for cordless vacuums officially recognize watts. The issue, however, is that there is no clear international standard yet for robot vacuum cleaners, which are a newer product category. Compared to watts, typically measured in the hundreds, pascals are often expressed in the tens of thousands, leading consumers to believe they indicate stronger suction.

In fact, in a test conducted in September by the Korea Consumer Agency, the maximum suction power of cordless vacuum models from Samsung Electronics, LG Electronics and Dyson all exceeded 280 watts. In contrast, Chinese models that advertised suction in the range of 18,000 to 48,000 pascals actually recorded suction power of only 58 to 160 watts.

A robot vacuum cleaner promotes its 30,000 pascals (Pa) suction power in a video ad played inside an electronics store in Songpa District, southern Seoul, on Dec. 2. [YI WOO-LIM]

A robot vacuum cleaner promotes its 20,000 pascals (Pa) suction power in an online ad. [SCREEN CAPTURE]

The government has not remained idle. Recognizing the confusion, the Korea Agency for Technology and Standards announced in July that pascals would no longer be considered an official indicator of suction power for dry-use robot vacuums. It proposed a revision to the national industrial standards (KS) to unify labeling around watts. After a public notice period that ended in September and a review by a technical committee, the final revision was published on Nov. 17.

According to the updated guidelines, “The maximum pressure value (kPa) of a cleaning robot’s suction system does not represent actual suction power (W). Using maximum pressure as an indicator of suction power can mislead consumers about the product’s performance. Key parameters directly related to dust suction performance include suction power (W) and airflow volume.”

“The establishment of the guideline itself is significant,” said Lim Sung-soo, a mechanical engineering professor at Kyung Hee University. “It’s important to actively promote this to encourage change. Efforts are also underway to establish an international standard that clearly defines suction power for robot vacuums in watts.”

However, as the KS standard is a recommendation and not legally binding, Chinese brands continue to use the Pascal labeling.

“The revised guideline has just been released, and our team has started reviewing it for potential adjustments,” said a representative of a Chinese appliance brand.

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.
BY YI WOO-LIM [[email protected]]