Air Distribution & Balance

Dampers

A component in an air-distribution system that restricts airflow for the purpose of air balance.

Squirrel Cage Blower

A cylindrically shaped fan assembly used to move air

Grilles

A louvered, often decorative, component in an air system at the inlet or the outlet of the airflow

Plenum

A sealed chamber at the inlet or outlet of an air handler. The duct attaches to the plenum

Registers

A terminal device on an air-distribution system that directs air but also has a damper to adjust airflow

Gauge

An instrument used to indicate pressure.

Velometer

An instrument used to measure the air velocity in a duct system

Pilot Tube

Part of an instrument for measuring air velocities

Static Pressure

The bursting pressure or outward force in a duct system

Friction Loss

The loss of pressure in a fluid flow system due to the friction of fluid rubbing on the sides. It is typically measured in feet of equivalent loss.

Velocity Pressure

The pressure in a ducts system that is created by the moving air. Velocity pressure is a function of the density of the air and its speed.

Total Pressure

The sum of the velocity and the static pressure in an air duct system

Diffuser

The terminal or end device in an air-distribution system that directs air in a specific direction using louvres

Propeller Fan

This fan is used in exhaust fan and condenser fan applications. It will handle large volumes of air at low-pressure differentials