How to select diffuser and grilles

Air diffuser and air grille are simple vents that are equipped for ventilation, heating, and air conditioning HVAC units. They are mainly installed in ceilings or walls so that the air coming from HVAC systems can be dispersed evenly throughout the room or desired area. Although it is widely used for enhanced air rotation in the room, it also helps in reducing noise. Some people also use them as return air vents.

As ventilation requires a certain degree of control over the air intake or exhaust rate and direction in enclosed spaces, to balance out, a vent cover performs that function. A vent cover also serves as an aesthetic seal over the gaping holes and outlets for ventilation, allowing ventilation to appear more seamless. There are three main cover types are mostly air diffusers, air grilles, and air louvers, they have many different types as follows:

               

Linear Slot Diffuser

               

Double Deflection GrilleR

Air diffuser: Square ceiling diffuser, round diffuser, jet nozzle diffuser, slot diffuser, swirl diffuser, T bar diffuser, ring jet diffuser, disc valve diffuser

Air grille: Double deflection grille, single deflection grille, linear bar grille, return air grille, egg crate grille, door grille, floor grille

Air louver: weather louver, gravity louver, drum louver, ball louver

To select an air diffuser and grille, we need to consider several things: the type and style, function, material, air volume requirement, pressure requirement, sound requirement, size requirement, and environment requirement. 

Many air diffusers are found on ceilings, often covering an air-con or air release outlet. Most diffusers come in square or circular shapes with vents, designed to match the diffuser's shape, facing different directions. The air diffusers can be as a shape of round, rectangular, or linear. A diffuser is effective when needing to distribute air evenly around a room or in specific paths.

A grille's primary function is as a cover to allow air to pass in and out through it. Air grilles are the only of the three options that are suitable for both air intake and air exhaust outlets from indoor spaces. What the grille has in simplicity, is compromised in function. The air grille does come in handy when you want a simple cover to extract air in and out unobstructed. Grilles also have more freedom in their placements at any spots, which generally need air to flow in and out.

A louver is a ventilating device that brings in fresh air from the outside. It serves as the entry and exit point of the ductwork because it covers the openings where your HVAC system takes in and exhausts air. 

Most of the time, many aircon ducts and mechanical ventilation inlets mounted in the walls use grilles for control over where the air is going. Some homes, hotels, or malls would choose slot diffusers set at an angle, to serve primary airflow directing.

The volume of the air diffuser or grille is what is needed for cooling, heating, ventilation, or requirements of the area served by the HVAC unit. The amount of airflow required when related to sound, pressure, or design limitations, determines the proper diffuser and grille or size.