Glossary
The words on spec sheets and listings, explained the way an installer would.
- Air watts
- A measure of a vacuum's usable suction power that combines airflow (CFM) and sealed suction (water lift). It is the best single spec for comparing central vacuum power units, far more meaningful than 'peak horsepower'.
- Bagged vs bagless
- Bagged units capture debris in a disposable bag, keeping the unit and filter clean. Bagless units use a canister with a filter or cyclonic separation; cheaper to run but messier to empty and often recommended to exhaust outside.
- CFM
- Cubic feet per minute of airflow. High CFM moves surface debris and hair quickly; it matters most for bare floors and large open rooms.
- Direct-connect electric inlet
- A wall inlet with 120V contacts inside the inlet door so an electric hose draws power without a separate cord (pigtail). Prong patterns differ between brand families, so hoses are not universally interchangeable.
- Exhaust vent
- A 2-inch pipe that routes the power unit's exhaust air outside. Optional on most bagged units, strongly recommended on bagless and cyclonic units to keep fine dust out of the garage or basement.
- Low-voltage inlet
- A wall inlet with two small contacts that switch the power unit on when a hose is plugged in or its handle switch is used. The most common inlet type; it does not power an electric powerhead.
- Pigtail hose
- An electric hose with a short power cord at the wall end that plugs into a standard outlet next to the inlet. Lets you run an electric powerhead on a home that only has low-voltage inlets.
- Powerhead
- A motorized brush head for carpet. Electric powerheads use a 120V motor and need an electric hose; air-driven (turbine) heads spin from airflow alone and work with any hose.
- Retractable hose system
- A system (for example Hide-A-Hose) that stores the hose inside the wall pipe itself. Requires special inlets and pipe routing, so it is mostly a new-construction or major-renovation choice.
- Water lift
- Sealed suction strength, measured as how many inches of water the motor can pull up a tube. Higher water lift helps with long pipe runs and embedded dirt.