Most people think all of the vents in their home do the same thing, but there’s a difference between supply and return grilles for controlling the airflow in your home. All of these components are generically referred to as vents, but they have different functions.

We should first clarify that the term “vent” is used for all supply and return air sources connected to a central air conditioning system. It’s pretty much an all-encompassing term for registers, grilles, and supply and return vents.

Supply Grille vs Return Grille – What’s the Difference?

What Is a Vent Grille?

A grille is a generic term for the protective cover for any type of supply or return vent. A vent grille is usually located in a wall or ceiling, but in some cases can also be found in the floor or baseboards. Vent grilles are used to direct the flow of air and hold in air filters.

floor vents vs wall vents
Image from Floor Register Resources


Supply Grilles

A supply grille covers the supply vents that pump hot or cold air back into your home. This is where the conditioned air travels from the heating/cooling system, through the ducts, out of the supply vent, and into the room. These are the vents you can put your hand in front of and feel the air coming out of them.

Return Grilles

The air return grille covers the vents that suck air back into the system to be cooled or heated before being pumped back into the home. They are also used to hold air filters in place and be purely functional, or decorative.

air return grille
Image from Decorators Supply


Supply and Return Air Duct Placement

There are design strategies for floor vents vs wall vents. For heating, supply vents are best located on the floor or near the baseboards because heat rises.

Supply air grille vents are also common below windows to create a barrier against the temperature emitted from the window.

For the return grille, it is imperative to keep the vents on the opposite side of the room so that air doesn’t go directly from the supply vent immediately back into the system. The air needs an opportunity to circulate through the room.

Keeping an optimal location in mind for supply and return air duct placement is important if you are replacing ducts and purchasing ducting supplies.

AC Grille vs Air Registers

Vent grilles and air registers are often referred to interchangeably, but there is a key difference between a register vs grille. Regular grills are fixed vent covers, while air registers use louvers/dampers to control airflow and direction.

Are you revamping your AC supply or return grille? Visit us for a large inventory of air conditioning parts Tampa needs to keep cool!

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