The purpose of the air conditioner grill is to diffuse the air from the ductwork. It directs the flow of air out of ducts or into the return air vent. Grills tend to be adjustable, so airflow in specific rooms can be restricted or even shut off entirely.
An air conditioning system has two coils, condenser coils and evaporator coils usually made of copper tubes with aluminum fins. The condenser coil or outdoor coil is the "warm" coil as it rejects the heat as a fan blows outside air over the surface.
