Furnace Damper: What, Working, Parts, Types, Motor, Lever, Control

The duct damper is another synonym for the furnace damper. Let us investigate the furnace damper’s functional components, model types, motor, lever, and control.

Every furnace requires a damper. In other words, it can be said that every fuel or combination of fuels needed a particular type of barometric damper. Single-acting dampers are used in the oil-fired furnaces and double-acting dampers are used in the gas furnaces.

A certain maintenance time frame is critical for the uninterrupted successful functioning of a furnace damper in Heating Ventilation And Air Conditioning (HVAC) systems. In this article, we will go into more detail about the furnace damper’s operation.

What is Furnace Damper?

The zone control method makes special use of the furnace dampers. Let us just emphasize on what the furnace damper accomplishes.

A furnace damper is a plate or valve. The external air motion inside an air handler, duct, VAV (Variable Air Volume) box, chimney, and other equipment of the air handler can be manipulated or terminated by either a damper.

225px Zone Damper 2
Image – Furnace Damper;
Image Credit – Wikipedia

The industrial sector frequently uses utilize of both large and miniature dampers. In this picture, Close-up of the motor connections. This damper can switch the electrical power to control additional “slave” dampers, minimizing the electrical load on the damper’s control circuitry and power transformer.

What does a furnace damper do?

A damper is an appliance that is able to monitor the stream of gases passing through it. Let us discuss the function of a furnace damper.

A furnace damper’s primary mission is to moderate airflow. The amount of fuel must be updated accordingly depending on whether a greater or lower temperature is required for the system. If a lower temperature is required, the fuel must simply be used in smaller portions.

The damper works in this way, so the furnace of the system can perform nicely and can also be accommodated by a person to adjust the system of the regulating in a manual way, so safety purposes can be maintained.

Where is the damper located on a furnace?

With the help of the damper, the orientation of the airflow can be monitored. Let us examine the location of a furnace’s damper.

The preponderance of the common dampers is located at a short distance from the HVAC unit’s base. The principal connections to the HVAC unit’s trunk are accessible upon entering the air processor or crawl area. The HVAC system in the majority of homes with a second level will contain dampers.

As the air ducts exit the main unit, you should make sure they are functioning properly. Anyone should be able to make an educated guess as to whether dampers are present in each length of ductwork.

How does a furnace damper work?

Dampers have quite a Battery Management System (BMS) connection that allows for intelligent control. Let us explain how a furnace damper performs.

A furnace damper operates by pushing or holding air from the designated region as needed and placed close to the distribution pipe’s mouth. The airflow will then be distributed once more by the pipe’s pressure to whichever zone is regenerating at the time.

Different from just sealing a vent in the floor or on the wall is a damper system. A closed vent still permits heated or cooled air to travel the whole length of the duct before stopping and wasting energy as it returns to ambient temperature.

Furnace damper control

Certain dampers are only offered in rectangular shapes. Let us discuss the control of the furnace damper.

Furnace damper control devices are driven by electric or pneumatic motors, which are in turn by a thermostat or a building manufacturing system. Side furnaces are turned by turning a handle on the ducts outside. On the other side, automatic dampers are used to automatically adjust airflow.

The fact that most of these dampers are employed in commercial applications, where rectangular ducts are frequently used and the convenience of manufacture are the main factors.

Furnace vibration damper

Vibration can be defined as the oscillation or repeating motion of a substance around an unchanging state. Let us speak about the vibration damper for the furnace.

Vibration dampers in furnaces produce noise and sound in the HVAC sector created by spinning parts, and moving air, and liquid through ducts and pipes. The vibration dampers are too little to make any difference because they cannot reduce the power.

According to the requirements of the particular system, vibration dampers are created in a variety of shapes and materials.

Furnace damper motor

Both gas and electricity can be used to power a furnace. Let us look at the furnace damper’s motor.

A motorized furnace can be referred to as a damper, which is any component of a home’s HVAC system that aids in stopping or controlling air flow.To control when they open or close, dampers can be counterweighted or spring-loaded, or they can be controlled remotely by a motor.

Controlling the temperature in a room is possible with a motorized damper that is in good working order.

HVAC damper types

Control dampers are used to direct a large amount of air. Let us list and explain the types of HVAC dampers.

  • Butterfly flat dish damper
  • Blade damper
  • Louver damper
  • Guillotine damper
  • Inlet vane damper

Butterfly flat dish damper

With the help of the Tandem Seal and ball bearings that are situated on either side of the casing, the flat dish that makes up the damper is easily movable because it is fused to the shaft. To stop any leakage near the shaft penetration opening, a Tandem Seal is used.

Blade damper

Blade dampers are devices made of flimsy metal plates that are used to restrict or stop airflow in duct work, chimneys, and HVAC systems, among other pieces of air handling equipment. They are largely required to guarantee the smooth operation of air handling systems.

Louver damper

Louver dampers offer trustworthy isolation and modulation. To achieve little to no leakage around the shafts, all designs are heavy-duty and incorporate an airfoil- or box-style blade shape, outboard bearings, and unique packing glands.

Guillotine damper

A body supporting a frame construction with an actuator situated above makes up the guillotine damper. The guillotine blade glides along the guiding channels built into the damper’s body and frame design as it is propelled by an actuator-powered feed-screw.

Inlet vane damper

To modify a blower’s flow or pressure relationship from the inlet side, employ inlet vane dampers. They are also known as internal vane controls or changeable inlet vanes. They are appropriate for applications that call for both volume control and fan shutdown.

Oil furnace damper

The barometric damper is a crucial piece of equipment in the oil furnace. Let us get into oil furnace damper in more detail.

An oil damper, also known as a barometer damper, is a device that controls the draught on oil-fired heating equipment, including boilers and water heaters. Gas-fired heating systems do not often require the oil damper; only oil-fired heating systems do.

The oil damper or barometric damper regulator on an oil-fired system is ordinarily a round tee fitted in the flue vent connector between the chimney and the heat source.

Coal furnace damper control

The intensity of the fire will be decreased by closing the damper. Let us discuss the damper control for a coal furnace.

The coal furnace’s dampers are draught controls and coal stove dampers. For bigger, automatically fed coal-fired boilers or furnaces, the system may include a thermostatically controlled automatic flue damper to adjust both draught and, consequently, the system’s heat output.

Coal-fired heaters also use manual dampers in the coal stove flue.

Wood furnace damper control

In the majority of homes, the top level dampers are left open during the summer. Let us talk about the damper control for a wood furnace.

A wood furnace damper control typically employed to decrease the flow of air exiting the firebox on older, less successful stove models. Modern wood stoves often don’t need dampers because of their newer structure.

Modern stoves that have been certified as meeting rigorous standards frequently don’t need dampers to operate normally.

How to tell if furnace damper is open or closed?

The top-level dampers are typically kept closed during the winter in most residences. Let us discuss how to determine whether or not the furnace damper is open.

We can recognize if a furnace is open or closed, by placing the hand into the fireplace before lifting the fire. It is a positive sign that the damper is open if one can feel a draught going down the chimney. When there isn’t any cold air coming out of the chimney, the damper is closed.

Closing the staircase dampers in the spring allows heat to spread naturally all across the apartment.

Furnace damper lever

For the furnace, closing the HVAC dampers is okay. Now let us check out the damper lever for the furnace.

A damper lever is termed as the furnace’s mechanism that restricts ventilation in the system. The fluid will undoubtedly warm up if the damper is left open over night, but it will also prevent the home’s occupants from being suffocated by odorless, colorless carbon monoxide.

Furnace backdraft damper

A backdraft resembles a fire damper in many ways. Let us talk about the backdraft damper for the furnace.

A furnace backdraft damper is one of the little components required to ensure that the ventilation system full fills its overall function and purpose of the furnace. Contaminated air can leave the dwelling by a backdraft, but it must not be forced to go back onto the residence.

Furnace zone damper

A volume control damper is another name for a zone damper. Now let us learn about the furnace zone damper.

A furnace zone damper is used to modulate velocity in an HVAC heating or cooling system. The registers of the zone dampers are checked and determines if the airflow begins after moving the damper to the open position.

It is probably a bad damper if the damper is closed and there is little to no airflow or even none at all.

Furnace bypass damper

Ensure that the bypass duct’s damper is closed. Let us talk about the what is a bypass damper in the furnace.

A bypass damper is a pressure relief valve and is located Between the supply and return ducts of the forced air ductwork where the bypass damper will open and direct some of the supply air to the return as the zone dampers begin to close.

To prevent outside air from entering the return ducting, it is made sure that any makeup or exterior air ducts that are connected to the system are properly sealed or closed.

Furnace stack damper

The most cutting-edge furnace damper is called a stack damper. The furnace stack damper should be visible.

Furnace stack dampers are used to stop rainfall from entering the furnace and lessen heat loss. It is crucial to select a sturdy damper from a reputable manufacturer given the climate these dampers are exposed to.

In comparison to a conventional edge-to-edge type connection, a standard-sized stack damper with a flat flange for installation can save time and money.

Furnace damper parts

Furnace efficiency is greatest at 68 degrees Fahrenheit. List the components of the furnace damper.

How to adjust furnace damper?

Dampers aid in the monitoring of the air stream volume in various sorts of outlets. Let us look at how to adjust the furnace damper.

  • The fan should be turned on
  • All dampers, all the time
  • Open each and every register in the apartment’s rooms
  • Identify which room is served by which duct
  • Make a first modification
  • Continue to watch and modify
  • Label the damper position
  • Adjust the damper one more before switching from heat to air conditioning

The fan should be turned on

If the thermostat doesn’t have a fan setting, turn it up so the system runs continuously as it completes these actions.

All dampers, all the time

Typically, this entails moving the lever to point in the same plane as the duct.

Open each and every register in the apartment’s rooms

Air is now circulating through the existing organization perfectly unhindered.

Identify which room is served by which duct

Follow each duct as far as possible from the main unit before it disappears. It will be clear from this which rooms they serve in general.Then, shut the dampers on each duct, one at a time, and check which rooms are affected, as there won’t be much airflow even with the registers wide open.

Make a first modification

It is time to start adjusting the dampers now that users are aware of which duct serves which rooms. Be aware that the damper lever is fully open when it is facing in the same vague direction as the duct. Lower air flows thru the lever the closer it gets to just being perpendicular to the duct.

Continue to watch and modify

After a few days of system operation, evaluate how comfortable each room is. If additional adjustments are required, wait a few days and evaluate the results. Continue until every room is at ease. Additionally, avoid fully closing any of the dampers to avoid disappointing the user.

Label the damper position

The damper’s position is level – Mark the location of the damper directly on the duct once the system has been adjusted to the highest level of comfort. Users won’t have to go through the entire experiment again the following year.

Adjust the damper one more before switching from heat to air condition

Miss the chance only to turn the dampers to be in the opposite position from where they are in cold weather and call it a day.In the heat as well as in the winter, a user can discover that their favored duct is largely closed. In order to please the user, redo the first tweaks, monitor, and adjust as necessary.


With this article, we can conclude what a damper is in a furnace system, how and when it operates, what parts relate to dampers, how dampers are classified, and many other things. Different types of dampers, including smoke dampers, manually operated dampers, fire dampers, and motorized dampers, can be categorized.