Registers and grilles are louvered or slatted grates that cover an opening in a floor, wall or ceiling through which air passes into or out of a room.
Registers
Registers are the vents through which air enters a room from the heating and cooling systems.
• They have a damper that allows them to control, direct and diffuse the amount of air that enters a room.
• Registers may direct air in one, two, three or four different directions.
• They are located on walls and ceilings so that cold air can fall into a room and in floors so hot air can rise.
• If they are blocked the temperature in a room can be greatly affected.
• Most registers have louvered dampers.
Grilles
Grilles are the vents through which air is pulled out of a room for circulation back to the central heating or cooling unit.
• They have no dampers behind the slats to close off the flow of air.
• They may be located in floors, ceilings and walls.
• Placement assists circulation within a room, and an unobstructed flow is required for heating/cooling system efficiency.
• You may have several small grilles located throughout your home or one large central grille installed near the furnace.
• Wall transfer grilles, door grilles and jump ducts are helpful for maintaining a steady return air flow in homes that have a centrally located grille.