“Here are some of the most common ones and how they operate:
Grilles:
Return Air Grilles: These grilles are installed in the return air ducts and allow air to flow back to the HVAC system for reconditioning. They typically have a fixed blade design to prevent unwanted tampering and can be rectangular or square in shape.
Supply Air Grilles: These grilles are used for the supply of conditioned air into the occupied space. They come in various shapes and designs, such as linear, slot, or square, and can have adjustable or fixed blades to control the direction of the airflow.
Eggcrate Grilles: These grilles have a distinctive eggcrate-like appearance and are often used in commercial or industrial settings. They allow for high airflows and provide minimal air diffusion, making them suitable for applications where strong air distribution is required.
Diffusers:
Ceiling Diffusers: These are commonly used in suspended ceiling systems and distribute conditioned air evenly across the space. They come in various shapes, including square, round, or rectangular, and have multiple patterns for air distribution, such as radial, concentric, or perforated face patterns.
Linear Diffusers: Linear diffusers provide a continuous line of airflow along the length of the diffuser. They are often used in long and narrow spaces, such as corridors or open-plan offices, to ensure uniform air distribution.
Swirl Diffusers: Swirl diffusers provide a swirling or rotating airflow pattern. They are often used in large spaces to achieve better air mixing and thermal comfort.
Louvers:
Fresh Air Louvers: These are installed on the building exterior to allow fresh air to enter the HVAC system while preventing the ingress of rain, debris, or pests. They often have adjustable blades to control the airflow rate.
Exhaust Air Louvers: Exhaust air louvers are used for expelling stale or polluted air from the building while preventing the entry of rain or pests. They also come with adjustable blades to regulate the airflow.
Louvered Dampers: These are combination devices that serve both as louvers and dampers. They can control the airflow and also provide protection against weather elements.
The operation of these grilles, diffusers, and louvers depends on their specific design and application. Generally, they either have fixed blades or adjustable blades, which can be manually or automatically adjusted to control the direction and volume of the airflow. Some advanced systems may even use motorized or automated louvers and diffusers that are controlled by the building management system to optimize air distribution and energy efficiency.”