What is a Damper in HVAC System?
A damper is a movable plate in the ductwork that regulates airflow. By opening and closing, dampers can be used to control airflow in a specific area or room, such as when zoning your home.
In HVAC systems, dampers are often located near an interface between return air and supply air or at the beginning of an enclosed space such as a closet or wall cavity. Because these areas have lower air flow rates than other parts of the system, it is important to include dampers to ensure proper ventilation throughout your home.
The purpose of dampers is to regulate pressure inside the ductwork. Dampers can also prevent outside air from entering through gaps around pipes and cables that run through walls.
Dampers are typically made of metal, although newer models are now composed of plastic. They can be manually operated or motorized to provide better control and ease of use.
Dampers are typically used in zoning or “zone control” systems. Zoning systems are designed to save energy by only heating or cooling specific areas of the home as needed.
For example, if you have a large home with many rooms, you may not need to heat or cool all of them at the same time. By using dampers, you can direct airflow to only the areas that need it, which can save on energy costs.
Dampers can also be used in exhaust systems to control airflow and prevent backdrafting. Backdrafting is when fumes and gases are drawn back into the building instead of being exhausted out.
This can happen when there is negative pressure inside the building, which can be caused by unbalanced ventilation or exhaust fans that are too powerful for the size of the ductwork.
How Do You Know When a Damper Needs Replacing?
Dampers can last for many years, but eventually, they will need to be replaced. Signs that a damper may need to be replaced include:
- Noisy operation
- Difficulty opening or closing
- Leaking air
- Misaligned blades
An professional HVAC technician will inspect the damper and recommend the best course of action.