How To Locate Dampers In Ductwork

How To Locate Dampers In Ductwork

Dampers are essential components in ductwork, but they can be challenging to find and identify. Ductwork is a labyrinth of narrow, twisting tubes that may go several stories underground or climb up through the attic. There are several different types of dampers you may need to locate, including fire dampers and auxiliary dampers. How you go about finding them will depend on what type you’re looking for. Each has a specific function, so identifying them helps ensure the ducts aren’t leaking air and that they operate properly when needed. Here are some tips on how to locate dampers in your ductwork system:

How To Locate Dampers In Ductwork? 

Check the ductwork during your initial inspection

When you are inspecting the ductwork of a building, keep an eye out for dampers. They will typically be located in the transition between the supply and return ducts. Dampers are often found at the connection between the supply and return ducts, as well as in the furnace room, where the air filter is located and where the supply ducts enter the room. Suppose the equipment being used to inspect the ductwork has the capacity to measure airflow. In that case, you may also be able to identify areas that are overpressurized and therefore most likely to be fitted with dampers. This will provide you with a good starting point for your subsequent investigations.

Use a carbon monoxide detector

If the building in which you are working has a gas-fired furnace and is fitted with a carbon monoxide detector (which it should be), you may be able to use it to locate dampers. Carbon monoxide detectors will typically register a rise in air flow immediately after the furnace is turned on. By monitoring the pattern of an airflow across the building, you can isolate the area that has been supplied with furnace return air by looking for a spike in the CO levels in that area. If you are unable to find a rise in CO levels, it may be because the gas-fired furnace is fitted with a CO-return device. This type of device is designed to remove CO from the air before it is fed back to the building and will therefore not register on the CO detector.

Use a remote-controlled video camera

If you are having trouble locating the dampers in the ductwork, you may want to consider using a remote-controlled video camera. There are a number of products on the market designed to locate ductwork sources of CO as well as locate dampers, such as CO-Viewer, CO Detector with Camera, and CO Detector with Fiber Optic Camera. The video camera will allow you to precisely locate and identify the dampers in the ductwork. If you are working in a large building, you may need to strategically position the video camera to get the best view of the ductwork. In smaller buildings, you can use the remote control to move the camera around inside the ductwork as needed.

Make use of your sense of smell

If you are having trouble finding the dampers in the ductwork, you may want to rely on your sense of smell to locate them. Dampers have a distinctive smell that is similar to that of burning oil. If you can’t find the dampers in the ductwork with the other methods suggested here, you can always rely on your sense of smell. Once you have located the dampers, you may be able to identify the make and model of the damper using a magnet attached to the end of a long pole.

Use an infrared thermal imaging device

If you are having trouble locating the dampers in the ductwork, you may want to use an infrared thermal imaging device. This type of device will allow you to “see” the warm inside surfaces of the ductwork, thereby revealing the presence of the dampers. The particular device you use will determine the exact range at which it can detect the damper. Typically, the best results are obtained when you hold the device approximately 6 inches away from the ductwork.

Why Is Damping Location Important?

  1. Air flows from the intake side to the exhaust side
  2. There is even pressure on both sides of the duct
  3.  The vent is in the supply duct instead of the return (prevents backPressure into the system
  4.  Dimmer ductworks properly before turning the equipment back on)
  5. Reduce air leaks

How To Locate Air Conditioning Dampers?

  • The first type of damper you will likely have to look for is an air conditioning (AC) damper. 
  • This type of damper is located in the return ductwork, which is the duct that brings air back into the house after it has been cleaned by the filter.
  •  The AC damper is used to close off the return duct when the AC units are not running. If you’re looking for an AC damper (or any damper, for that matter), the best thing to do is to follow the path of airflow through the system. 
  • Start at the filter and trace the flow of air through the ductwork as it travels to the return duct. 
  • As you are following the flow of air, look for an opening in the duct. This is where the AC damper will be located.

How To Locate Heating System Dampers?

  1. If you are trying to locate a heating system damper, start by following the path of the warm air as it travels through the ductwork. 
  2. Once you know the general path the warm air travels, you can try to locate any openings in the ductwork. 
  3. These are where the heating system dampers would be located. There are a couple of ways to identify these openings. First, you can look for any variations in the size of the duct. 
  4. The ductwork that houses the heating system is likely to be a bit larger than the ductwork that is dedicated to the air conditioning system.
  5.  A second way to identify the openings for the heating system’s dampers is to listen for the sound of air rushing through the ductwork. 
  6. The openings for the heating system damper will sound different from the sound of the AC system’s return opening.

How To Find The Supply Registers For Your Dampers?

  • In order to close the dampers, you may need to go to the supply ducts where the dampers are located. If you have found the dampers but can’t close them, this is likely the problem.
  •  You can easily find the supply ducts by tracing the flow of air back to the source. Start at the return duct and follow the path of the air as it travels to the filter.
  •  At the filter, you will see the ducts split and go in two directions. One of these ducts leads to the return and the other leads to the supply. 
  • As you follow the path of the air, you will likely notice that it travels through another duct on its way to the supply. This is where the dampers are located.

Final Words

Hopefully, you now know how to locate dampers in your ductwork! If you ever find yourself needing to locate or close a damper in the ductwork, hopefully, you now know where to look. While locating dampers in ductwork can be challenging, it’s not impossible. Follow the path of airflow through the ductwork, and you’re sure to locate them sooner or later!