Trade usage splits the outlet family three ways: a grille is just a face with fixed or adjustable bars, a register is a grille with a damper behind it, and a diffuser spreads air in a pattern. Residential floor and wall supplies are usually registers, and the damper lever lets a balancer trim the flow to each room.
Half the registers in the house are closed, that's why the static is through the roof and the coil keeps icing.
Closing registers in unused rooms raises static pressure and can ice the coil; it rarely saves money.
Also heard as
- vent
Related terms
Diffuser
A supply air outlet, usually in the ceiling, that spreads air into the room in a set pattern and mixes it with room air.
Damper
A blade or set of blades in a duct or opening that controls, balances or shuts off airflow.
Static pressure
The pressure air exerts outward on duct walls, the resistance a fan works against, measured in inches of water column.
Return air
Air drawn back from the conditioned space to the air handler to be filtered and conditioned again.