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Difference Between Dampers and Louvers

Dampers and louvers both are used to manage the free flow of air but with different purposes. People often get confused between louvers and dampers due to a few of the similarities they have. For instance, they both have exterior frames and horizontal blades. Moreover, they are mostly placed on walls and can work as either the supply or exhaust entry point for the ventilation system.

These are the only similarities they have. In this blog, we will discuss mainly about the differences between louvers and dampers. The most prominent difference between them is that when it comes to a building ventilation system, louvers are used to separate things like sand, rain or snow from the airflow whereas backdraft dampers are used for preventing airflow in a single direction. 

Dampers and Louvers

As mentioned above dampers and louvers both control the airflow in a process system or enclosed area. Dampers can be found in both motor-driven and gravity-operated versions. The usage of motorized dampers is typically seen in places where a very tight seal is needed or when the damper needs to work against the air pressure.  Gravity dampers, also known as shutters, are needed in horizontal fan exhaust applications. Gravity dampers need to depend on air pressure to open up because of the absence of motor.

Types of Dampers in HVAC

On the other hand, louvers are used in places where protection from water infiltration is needed. When an application needs air shutoff, both the support of damper and louver is required as louvers are equipped with fixed blades that are unable to close.

Different types of Dampers and Louvers

Dampers are available in various shapes including square, circle, rectangle and they are made of metal. Some dampers can be used for pressure relief and some are used within particular HVAC systems

Dampers are mainly classified into the following types

  • Backdraft dampers – these dampers are made of galvanized steel frame and extruded aluminum airfoil blades. These vanes offer better strength with less noise and static pressure
  • Counterbalanced backdraft damper – like backdraft dampers, they are also made of galvanized steel and designed to fulfill application needs depending on pressure, temperature, and velocity. 
  • Industrial dampers- these dampers are mainly of three types 
  • Bubble tight dampers – these bubble-tight dampers are utilized in applications that need shut off capabilities under extreme conditions. They can also be used in nuclear power plants and they are tested based on the ASTM and ASME standards.
  • Round isolation dampers – they are designed with butterfly blades and made of carbon steel. They offer low leakage on both HVAC and process systems.
  • Round discharge dampers – they are made of galvanized steel and mainly used on the discharge side of an axial flow fan. They stop powered fan shutdown and are capable of bearing pressure and velocities in multi fan applications.

Louvers are classified into following

  • Stationary louvers – they are designed with angled or airfoil style blades that not only protect from extreme weather conditions but also offer sound attenuation 
  • Adjustable louvers – equipped with airfoil blade, these louvers are easily adjustable
  • Combination louvers – as the name suggests these louvers act as a combination of louver and damper. They have fixed louver blades in the front and adjustable blades in the rear that can be opened and closed 
  • Air measuring louvers – they have vertical blades that restrict water from entering inside 

The difference in terms of panels 

The Louver is a kind of a shutter or blind that comes with horizontal slats that are angled to allow space for light and air but restrict rain and direct sunlight whereas dampers control the airflow. In HVAC systems, dampers and louvers are used to regulate the flow of air. One can select between dampers and louvers based on the design requirements. Dampers also have the capacity to restrict smoke and heat when used as smoke detectors. 

  • The most prominent difference between Louvers and Dampers lies on their blades. Louver blades are usually constant and unable to move while the dampers have movable blades.
  • As louvers do not have the capacity to move, they can not control the regulation of airflow but dampers being movable can act as a regulator to control airflow

We hope that this article will help you get some clarity on the differences between louvers and dampers and decide which one will be the right one for your application. Feel free to reach out to EB Air Control Inc. for a query related to dampers or other HVAC products.

ebair_wpDifference Between Dampers and Louvers

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