(Air Flow * Vacuum)/8.5 = Air Watts Air flow is CFM (cubic feet per minute) Vacuum is inches of water lift so a Dyson has approx 350 air watts as stated in the advertising. lets test that against a Kirby which has approximately 45 inches of water lift as tested, and 110 cfm as stated in the technical specifications sheet provided by the Kirby company. so: 110cfm X 45 inches = 4950 4950 / 8.5 = 582 air watts test 2: I went a got the cheapest Regina bagless $79.95 and tested it. 50 cfm and 65 inches of water lift so: 50 cfm X 65 inches = 3250 3250 / 8.5 = 382 air watts (thats more air watts than the Dyson at 15% of the cost) Bagless vacuums are deceiving they really look like they are cleaning when in fact most dirt cups only hold 10-20 ounces of dust. Compare that to some vacuums we see that hold 10 to 15 pounds and you get the idea. Well it looks like Dyson better find a new rating system quick! Maybe they should try the Cleaning effectiveness per amp method :) see the AMPS section. |