A damper is anything in a commercial building’s HVAC system that helps stop or regulate airflow. There are several types of dampers out there, so knowing what they are and how they work is crucial to choosing the best fit for your system. Lloyd Industries has been the leading manufacturer of dampers for over 35 years, helping building owners every day.
What is a Fire Damper?
A fire damper is a passive protection product placed throughout heat, ventilation, and air conditioning ducts to prevent the spread of fire in your building. Fire dampers are a crucial part of fire safety. In the event of a fire, the damper has a fusible link that is signaled when the temperature rises and it begins to melt, triggering the door to close.
Fire dampers can be installed in or near the wall or floor at the point where the duct penetrates, so the wall or floor retains its integrity and fire rating. This is true whether it is a ducted or open plenum return application. An open ceiling, or open plenum, has become very trendy versus lay-in ceilings. However, the importance of dampers remains the same.
3 Types of Fire Dampers
- Static
- Dynamic
- Combination
Static Fire Dampers
Static fire dampers are designed like a curtain and are used to stop airflow as soon as a fire is detected. In the event of a fire, your building’s fire system is set up to trigger your HVAC unit. Once the fans in your HVAC unit shut down, the static damper closes from lack of air pressure, preventing smoke and flames from passing through your HVAC systems ducts.
Static dampers, unlike dynamic dampers, are designed to cut off airflow. Closing off the airflow is an effective way to keep a fire from spreading. Lloyd Industries carries a wide selection of static dampers that can fit any unit.
Dynamic Fire Dampers
Unlike static fire dampers, dynamic fire dampers are used when the fan in your HVAC system stays on in the event of a fire emergency. Dynamic dampers are designed to close against moving air. Therefore, they must be UL 555 rated and carry an airflow velocity and pressure differential rating. In addition, dynamic dampers go through rigorous testing where they are exposed to the elements they will be meant to operate against.
Combination Fire Dampers
Combination dampers are fire-smoke dampers that operate as one. These dampers were designed to block flames from passing through and prevent smoke from spreading. Combination dampers have multiple blades tied to an actuator that is equipped with a heat response device and a smoke detection system. If fumes or elevated temperatures are detected near the damper, they will close.
Spring-loaded or Motorized Damper; What’s the Best Choice?
- Spring-loaded
- Motorized
How a Spring-Loaded Damper Works
Spring-loaded dampers are designed to close once they detect extreme heat. The spring-loaded design causes the doors of the damper to have a spring-like action when they are forced to shut. Since the HVAC system fan is designed to stay on, the air pressure from the fan helps the doors of the damper to spring shut.
All Lloyd Industries dynamic dampers are spring-loaded, allowing the fan to remain running in the event of a fire emergency. Spring-loaded dampers are also found in HVAC units that don’t have an automatic shutoff built in.
How a Motorized Damper works
A motorized damper allows the owner to control the temperature while regulating airflow throughout their building. Motorized dampers are controlled by a thermostat or a built-in automation system.
Most systems that use motorized dampers have been customized to their system. For example, a facility that works with airborne chemicals will have a separate HVAC system that uses a contamination alert and motorized dampers to prevent the spread of chemical or microbial chemicals from traveling throughout a building.
Are Motorized Dampers Required?
Motorized dampers allow you to control the temperature of your building using zones and regulate airflow. According to the International Code Council, motorized dampers are required in commercial buildings apart from three exceptions.
Non-motorized dampers can be used if any of the following are true:
- A building is less than three stories in height above grade plane.
- A building of any height is in climate zones 1, 2, or 3.
- A building where the design exhaust capacity is not greater than 300 cfm.
While we recommend motorized dampers no matter the situation, it’s crucial to check your state’s regulations and abide by them.
What is a Zone Control System?
A zone control system uses thermostats to connect to the central control panel of your HVAC system to open and close dampers distributed throughout your ductwork, allowing you to block or release hot or cold air.
A zoned HVAC system divides your building into multiple zones controlled by its own thermostat. For large commercial buildings, each floor will have its own HVAC unit and at least two thermostats to control the temperature.
For smaller commercial buildings, there may be only one thermostat per floor. However, new construction buildings are generally equipped with a multi-zone thermostat. This allows you to place external sensors in each zone and control them all from your phone.
How to Test Your HVAC Zones
Understanding the HVAC zones in your building is important for comfort and efficiency. If one room is uncomfortably hot while another is too cold, your system is not working effectively and may not be zoned properly. Taking the time to ensure each room is vented properly will increase your satisfaction with the system and avoid problems in the long run.
If you don’t have a map that clearly outlines the zones in your building, consider taking the time to test your unit. Start by opening your vents. Then, follow the flow. Finally, be sure to mark them for the next time.
When to Schedule Damper Maintenance
Now that you know all about your dampers, it’s crucial to schedule maintenance. There are several moving parts when it comes to your HVAC system, and hiring a professional to inspect all your dampers and ensure your system is working as expected will keep it moving for years to come.
While maintenance is not required on a semi-annual basis, Lloyd Industries recommends having your dampers looked at twice a year. By caring for your dampers consistently, you are ensuring your system will do its job in the event of an emergency. With proper care and maintenance, your dampers can last around 20 years.
