Vacuum Cleaners: Is it Air Flow or Suction?
Written by The Vac Tech
Suction is often misused as a measure of cleaning power but when it comes to vacuuming, air flow is everything.
Working on commercial cleaning equipment taught me this important lesson. Customers complained of their wet vacs and carpet extractors not picking up the water. Our suction gauge told me their equipment had great suction so why no pick up? After purchasing an air flow meter I got my answer, no air flow. This information easily translated to residential vacuum cleaners and customer complaints of poor pick up.
Suction is the measure of pressure created by a vacuum motor measured in inches of water lift.
Air flow is the measure of air volume flowing through a system measured in CFM or cubic feet per minute.
A simple illustration would be a partially clogged hose that would not affect the measure of suction but would certainly reduce air flow. This shows up mostly when using a floor brush or sucking through a large opening such as the nozzle of an upright vacuum or power brush. So anything that reduces the volume of air that can travel through the system will result in poor pickup. Here are some examples of what can cause poor air flow.
1) Clogged filters including the exhaust filter.
2) Dirt in the motor fan.
3) Partial clog. A full clog causes an obvious no suction condition.
4) Poor quality vacuum bags.
5) Picked up fine powders.
6) It was a piece of junk when it was new and there is no hope.
So don’t get excited about claims of no loss in suction, it is all about air flow. All bagless vacuums will lose air flow during normal operations and only a select few bagged vacuum cleaners maintain air flow, but that is another article.
The Vac Tech (Since1966)