The HVAC unit is a crucial part of the infrastructure in your home. Your HVAC system regulates heating and cooling in to maintain a comfortable indoor temperature. When functioning properly, you should not notice any uneven temperatures throughout your home.

What Is an HVAC Damper?

HVAC dampers, also known as duct dampers, are specially designed movable plates. These are found inside of your air ducts. These dampers can be opened and closed to regulate airflow to achieve the desired temperature.

How Does an HVAC Damper Work?

HVAC dampers function as valves that control the flow of air in your home. When the dampers are closed, they block the flow of air coming through your ducts. The principle is similar to the way that a dam controls the flow of water coming in or out from a river.

When your HVAC dampers are open, they allow air to flow freely through all your ducts. This is different from the way that a vent works. Ducts are much closer to the source of air while vents are usually placed a considerable distance away. Having ducts closer to your air source will enable you to control airflow more effectively.

When Should You Open or Close Your HVAC Dampers?

If you want to divide areas of your home into strategic temperature zones, you can choose which dampers to open or close. Creating temperature zones is helpful for members of your household who may desire to have control over the climate in their specific areas of the home. For example, the majority of those in your household may want the AC set to 70 degrees Fahrenheit while a couple of members feel that this is too cold and can shut the dampers that lead to their rooms.

You can also close your HVAC dampers to save energy. For instance, if certain areas in the home will not be occupied, you can close your dampers to heat or cool only the areas that are being used.

If you notice that there are areas in your home where the temperature is typically warmer or colder, you can adjust the dampers to make temperatures even. For example, if you notice that the air is hotter upstairs during the summer, you can adjust the dampers to direct more cool air to that location.

Where Can You Find Your HVAC Dampers?

Most homes that feature HVAC dampers will have them located between your primary trunk line and your HVAC supply duct. The trunk line will be the line that leads directly from your furnace. This line is designed to supply air throughout your property. The supply ducts are usually small, round lines that circulate air through all the rooms.

Keep in mind that the placement of dampers in every home is far from uniform. Some homes may have dampers at the points listed above. In some homes, they are not present and will need to be installed. If dampers are present, the most common areas to find them will be your basement or crawlspace.

Spotting your HVAC dampers shouldn’t be much of an issue. Designs from different manufacturers may vary somewhat but are generally quite similar. They will usually all have a handle on the outside, and this handle is used to manipulate them.

What Are the Two Main Types of Dampers?

There are two main types of HVAC dampers that are available on the market. Automatic dampers are controlled by a motor that can automatically open and close the adjoining valves. This saves you the trouble of having to manually adjust them. It’s a feature that will prove to be very handy when seasons change.

Manual dampers must be opened and shut by hand. They are connected to valves that you can manipulate. This type of valve tends to be cheaper and is less likely to require maintenance often. However, you will need to keep an eye on them to make sure that they continue to function properly.

While these are the broadest categories of HVAC dampers, they are broken into subcategories by their design. These dampers are as follows.

Butterfly Flat Dish Dampers

The most common type of dampers you will find in residential and commercial HVAC systems are the butterfly flat dish variety. Butterfly flat dish dampers are circular with a half circle attached to each side. The half circles are designed to behave like flaps, and these flaps open and close to control airflow.

Blade Dampers

Like butterfly flat dish dampers, blade dampers are also common. There are two types of blade dampers, and these are parallel and opposed blades. Parallel blades are held together by an elastic material. Opposed blades are forced to touch one another via the air in the ducts, and they rotate on an axis and slide against one another. Both types of blades are attached to a shaft, and they rotate when a motor is activated.

Guillotine Dampers

Guillotine dampers are commonly installed in conjunction with grills or registers, and they are positioned on duct outlets. Blades are attached to a rod that moves in a vertical direction, and they completely stop airflow when closed. However, air flows freely when the blades are open.

Louver Dampers

Louver dampers are typically installed on the return and supply ducts of HVAC systems. The chief purpose of louver dampers is to ensure the energy the fan uses is regulated and airflow is easily controlled. Louver dampers are comprised of two plates that are connected via hinges. One plate has openings that allow air to pass through it, and the other plate has slats that are designed to control the flow of air.

Inlet Vane Dampers

Although inlet vane dampers are installed on the supply duct, return duct and exhaust in HVAC systems, the most common place where they are found are the return ducts. Inlet vane dampers function as an automatic valves to regulate the indoor temperature. If the temperature outdoors is higher than the indoor temperature, these dampers will open to allow cool air to flow freely. If the outdoor temperature is cooler, then the dampers will close.

Adjusting Dampers

Adjusting dampers are in different portions of the HVAC system, and their chief purpose is to regulate the temperature in each room. These dampers can be opened or closed to adjust air flow.

When Should You Call an HVAC Technician?

If you find that your dampers are not working as designed or see rust, you need to contact an HVAC technician for help. Also, you should have your dampers checked regularly to make sure they continue to function optimally. You can have your dampers checked during your regularly scheduled HVAC maintenance.

Contact TR Miller for Your HVAC Damping Needs

TR Miller Heating, Cooling & Plumbing is available to address all your HVAC-related needs. We specialize in air conditioning, heating, tankless water heaters, sump pumps, and more. We have a long record of professional service in Plainfield, Illinois and surrounding areas. Contact us at any time to learn more about our services and how we can help keep your home comfortable and safe.

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