What Are Air Watts?
Air watts combine airflow and suction pressure into one measurement. Understanding all three values helps you make a more informed comparison between central vacuum systems.
Airflow and water lift must be measured at the same operating point for a meaningful result.
Airflow
The volume of air moving through the vacuum system, measured in cubic feet per minute.
Water Lift
The vacuum’s suction pressure, commonly measured in inches of water lift.
Air Watts
A combined measurement showing how airflow and suction work together.
Why Airflow and Water Lift Both Matter
Water lift measures how strongly a vacuum can pull when airflow is restricted. Airflow measures how much air moves through the system.
A vacuum needs both. Suction loosens and lifts debris, while moving air carries that debris through the hose and tubing to the dirt canister.
- High water lift with little airflow cannot carry debris efficiently.
- High airflow without enough suction may struggle with heavier material.
- Air watts help illustrate how the two measurements work together.
Air Watts Calculator
Enter airflow and water lift measured at the same motor orifice.
Think About a Penny and a Vacuum Hose
Place the open end of a vacuum hose tightly over a penny so that no air can enter. The vacuum creates suction, but the penny does not move because there is no airflow.
Tilt the hose slightly and allow air to enter. The moving air carries the penny through the hose and into the dirt canister.
Compare Performance at the 5/8-Inch Orifice
Vacuum motor performance changes as the tool opening changes. An open hose may produce high airflow, while a blocked hose produces maximum water lift but no airflow.
The 5/8-inch, or 0.625-inch, orifice closely represents the opening found on many cleaning tools. It provides a useful reference point for comparing practical cleaning performance.
Compare motors using the same orifice, voltage and testing conditions. A peak air-watt rating taken at maximum voltage may not represent normal cleaning performance.
Look Beyond One Number
Use consistent testing information when comparing central vacuum motors and complete power units.
Use the Same Orifice
Airflow, water lift and air watts should be compared at the same tool opening or test orifice.
Check the Voltage
Confirm whether the rating reflects normal operating voltage or a maximized peak-voltage test.
Review the Complete Curve
Motor performance changes from an open hose to a sealed hose. One isolated value does not show the full curve.
Do Not Overlook Motor Brush Life
Vacuum motors contain carbon brushes that gradually wear as the motor operates. Brush life is normally measured in operating hours rather than calendar years. When comparing motors, review expected brush life along with airflow, water lift and air-watt performance.
Need Help Choosing a Central Vacuum?
Contact VacuMaid or speak with an authorized dealer for help comparing power units, motor specifications and system sizes.
I couldn’t have said it any better myself