Different Types of Fire Dampers in HVAC and Ductwork

Modern buildings are incredibly safe, but that wasn't always the case. Building codes and improved construction techniques have reduced the likelihood of fires and other disasters from occurring and prevented the spread of damage when they do. One key part of limiting the spread of fire in a building and keeping occupants safe is the fire damper.

United Enertech brings decades of excellence to their fire damper designs to help buildings operate safely and efficiently.

What Are Fire Dampers?

In the past, buildings were incredibly vulnerable to fires due to how quickly a fire could move through a building. Modern buildings are designed so that if a fire occurs, it will be compartmentalized so that occupants will have sufficient time to escape and emergency crews will have time to respond. Walls that play a role in this compartmentalization have fire ratings, usually given in terms of hours, which shows how long that wall assembly can withstand a fire.

The fire rated wall assemblies work extremely well, but ductwork adds in a complication. To pass conditioned air throughout the building, the fire rated wall assemblies must be penetrated by ductwork. A large hole in these walls presents an obvious path for fire to spread unless something is done about it. That’s where fire dampers come into play. Fire dampers are designed to stay out of the way and let the HVAC system function as designed, unless the fire dampers detect high temperatures.

Fire dampers are typically loaded with a thermal element that is designed to melt at a particular temperature. When the element or fusible link melts, the fire damper closes and blocks off the ductwork in order to effectively seal the fire rated wall closed and protect the building. Fire dampers are critical for keeping HVAC systems operating as designed when everything is okay, and for keeping the building safe when disaster strikes.

The Main Types of Fire Dampers

While fire dampers all typically perform the same function, their form and how they carry out that function can differ. Some of the main types of fire dampers include:

Curtain-Type Fire Dampers

These types of dampers operate just as the name suggests. When curtain-type dampers detect a fire, the fusible link melts which allows the metal curtain to drop and block airflow. The curtain remains closed until being manually reset. These fire dampers are foolproof and highly effective due to their simple construction and high-quality design.

Multi-Blade Fire Dampers

Multi-blade fire dampers consist of several blades that rotate closed to block airflow. Unlike curtain-type fire dampers, the blades of these dampers are permanently fixed in the airflow. When fire is detected, the blades rotate to seal off the ductwork. Multi-blade fire dampers are ideal for larger HVAC systems and industrial applications which can move large amounts of air at higher static pressures.

Radiation Dampers

Ductwork that penetrates a ceiling presents unique obstacles that must be addressed. Ceiling radiation dampers are fire dampers specifically designed for this scenario. They typically have flaps like a butterfly’s wings that snap shut when fire is detected to seal off and protect the upper floor.

Static or Dynamic?

While curtain and multi-blade fire dampers describes how the air is stopped, those types of fire dampers can also come in either static or dynamic forms:

Static Fire Dampers

Static fire dampers typically rely on the force of gravity to drop the curtain or close their blades. Static fire dampers are simpler and less expensive, but require that the HVAC system shuts down in case of a fire. The force of air flowing through ductwork can be enough to keep static fire dampers open, which renders them ineffective.

Dynamic Fire Dampers

Dynamic fire dampers are designed to operate in systems where airflow is maintained during a fire emergency. They require an external source of energy, often a spring or a motor, to give them enough power to close against the flow of air. Dynamic fire dampers are more expensive due to the extra components and more complicated construction, but their role is critical.

United Enertech Fire Dampers Bring Innovation to Safety

The advanced design and manufacturing process of United Enertech's dampers has set us apart as leaders in fire safety. United Enertech’s fire damper durability and compliance with safety standards make them an easy choice for architects and building owners. With a wide variety of custom damper solutions available, including specialized dampers for specific HVAC system needs, United Enertech has the right solution for any application.

Choose United Enertech Fire Dampers

From Ceiling Radiation Dampers to dynamic fire dampers, United Enertech has the components you are looking for. Choosing the right type of fire damper is critical to keeping your building safe. United Enertech provides fire dampers that are always up for the challenge.

To learn more about selecting the right fire damper for your application, reach out to the fire safety experts at United Enertech today!