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What are Air Watts in Measuring Vacuum Cleaners?
What are air watts? They are the figure that tells you how much work a vacuum does at the end of the hose. Unlike horsepower, the figure describes suction rather than the motor. Here is how the number works, and how to use it when you compare machines.
What are air watts, exactly
An air watt combines two things: airflow and suction. You multiply airflow in cubic feet per minute by water lift in inches. So the result reflects both how much air moves and how hard it pulls. Because it blends the two, it tracks real cleaning better than any single figure.
Why air watts beat horsepower
Horsepower measures output at the motor shaft. In contrast, this figure measures what arrives at the nozzle. A machine can post a big horsepower number and still move very little air. Therefore it answers the question you actually care about.
What a higher rating buys you
A higher rating usually means more dirt lifted out of carpet and upholstery. That matters most in homes with pets or allergy sufferers. Because the figure also reflects airflow design, a well-built system holds its suction as the bin fills. Meanwhile a weaker design fades long before the bin is full.
Comparing machines fairly
The rating gives you a common yardstick, so you can set two units side by side. Still, ask how each maker measured. The industry test method is ASTM F558, so ask whether the numbers follow it. Ask for water lift as well, since it shows how the unit copes when the hose is partly blocked.
What we publish
We list air watts, amps and water lift for every InterVac system. For example, the GarageVac GH120 is rated at 514 air watts and 10.7 amps at 120V, with 110 inches of water lift. As a result, you can hold any other unit to the same test.