HVAC diffuser is very common in heating, ventilating, and air conditioning systems. They are used on both all air and air water HVAC systems. It delivers both conditioning and ventilating air. Evenly distribute the flow of air in the desired directions. To enhance the mixing of room air into the primary air being discharged. And create low velocity air movement in the occupied portion of the room.

The HVAC diffuser can be of various types depending on the shape and the way of letting the air pass through them. The main series is an air diffuser, air grille, air louver, air register, air damper, and duct accessories.

Air balancing is a term commonly used in HVAC system operations. Experts consider it important for better performance of HVAC that the air in the room should be balanced and reach each tiny spot of the area. The aim of an HVAC diffuser is to fulfill this very term and regulate the air thoroughly.

When the HVAC diffuser is called a supply air diffuser or supply air grille, usually there is a damper for the diffuser or grille that helps in adjusting the velocity of the air passing through the vents. This step mitigates the speed of air and builds the pressure of the air inside the diffuser.

As we know that different shapes of air diffusers and grilles have different dampers and materials. The damper has opposed blade damper, butterfly damper and swirl slide damper type. It has materials of aluminum, plastic, and galvanized steel for optional. Please find below hvac diffuser size with the damper for your reference :

1. Square air diffuser :

Damper: Aluminum opposed blade volume control damper gear operated

Standard size: 150x150mm,225x225mm,300x300mm,375x375mm,450x450mm

2. Round ceiling diffuser

Damper: Plastic butterfly damper or round swirl damper

Standard size: 150mm,200mm,250mm,300mm,350mm,400mm

3. Air grille and louver

Damper: Aluminum opposed blade volume control damper mechanically operated

Standard size: 150x150mm,200x200mm,250x250mm,300x300mm,350x350mm another size available.

Butterfly damper can be put into the round diffuser or round duct. It consists of a single or two round blade that pivots on a single, central hinge. When a butterfly damper fits into a round diffuser. The design damper blades is rotating in opposite directions to one another under opposed blade configuration. It uses to control airflow coming out from the HVAC system. When it use to round duct, the damper has a seal that the edge of the blade connects with all the way around the circumference of the pipe or duct. When the damper is fully closed, the edges of the blade press firmly against the seal to keep about 90% of the materials isolated.

The butterfly damper is used to restrict the flow of air vents in ducting systems where flow control and low leakage isolation are a priority. These dampers are especially useful in applications such as incinerators, balancing systems, control air systems, stack isolation, and scrubber systems. Butterfly dampers function best in round ducts, as their central pivot point allows them to maintain a tight, continuous seal around the damper’s circumference. Various types of seals can be used with butterfly dampers to offer better isolation and sealing potential.