Tips When Adjusting The HVAC Dampers In The Summer

Damper Position In Summer

If your home is too hot during the summer season, there is a possibility that your furnace dampers are not used correctly. These dampers control airflow in your ductwork, balancing overall airflow in your home.

To help you achieve year-round comfort, here is a comprehensive guide in balancing your HVAC system.

Should the damper be open or closed in summer? The reason is that cool air sinks, leaving the upper parts of a building such as attics, sweltering hot during summer, and basement cold. Dampers located at the lower levels of an establishment should be closed during summer to maximize cool airflow at the upper levels.

Learn more about why dampers should be closed at the lower parts of a building during summer in this post.

The different types of dampers will also be tackled, along with some tips on adjusting HVAC dampers. Let’s get right into today’s topic to optimize your life.

Dampers During The Summer Season

A damper is a plate or valve regulating or stopping the airflow inside a chimney, duct, air handler, VAV box, or other air-handling equipment. In the case of HVAC dampers, it is a plate that regulates the flow of air inside ducts.

It is an excellent tool for controlling the overall temperature and balancing airflow inside a building, whether in your home, workplace, or industrial environment.

During the summer season, when the air outside is warm, you have to adjust your dampers to help your home remain cool all the time.

You should adjust your dampers to let the airflow go to the upper part of your home, as areas close to the roof are consistently warmer. If your adobe doesn’t have dampers, close several air registers located on the first floor.

Adjusting Your Dampers For Better AC Distribution

When adjusting your dampers in summer, your goal is to properly distribute cooled air from your heating, ventilation, and cooling system.

Since cool air tends to sink during the hot days of the season, resulting in warmer attics and cooler basements, you have to close dampers for ducts that deliver cool air to the first floor and basement.

This will force more supply of cool air to the second floor and upper areas of a building.

Closing dampers on the lower levels of a building won’t make those areas sweltering hot. As mentioned earlier, cold air sinks, making it flow downwards to cool the lower areas of your home.

Meanwhile, homes with no second floor can still adjust the dampers to send more cooled air to primary living spaces during summer.

So you can maintain maximum comfort in common living spaces like living rooms, bedrooms, or home offices even on the scorching day of the season.

Know The Different Types Of Dampers

To help you familiarize yourself with your HVAC dampers, here are the types of dampers you should know. Each type works differently from one another, providing unique advantages to meet the needs of the users. Check them all out:

Balancing Dampers

Balancing dampers helps to manage air pressure in spaces connected to the ductwork. However, annoyances can be experienced by inhabitants due to air pressure imbalances such as odd gusts of air, slamming doors, or worse, causing system difficulties.

In addition, when a place is not cooled or heated evenly, it can be more difficult to cool or heat. Air handling devices also experience strain due to this issue.

Aside from that, balancing dampers are modified by technicians by measuring a room’s air pressure while adjusting the damper blades’ angle.

These blades are fixed in a position to maintain the air pressure needed. In case you need to make changes, you can also unlock these blades whenever you want to.

Control Dampers

Control dampers are used at various points and the ductwork to manage airflow through the system. They can also be altered to suit cooling and heating air mixing zones.

These dampers fully open or close their blades several times a day. In addition, you may utilize different actuators to control the movement of the blades fully.

Multi-Zone Dampers

Multi-zone dampers are used by small-scale and single buildings with single air handling. This type of damper is a collection of many dampers that are connected to a different zone.

  • They use multiple actuators that control different zones.
  • You can buy these dampers as a package along with the air handling unit.
  • They control the airflow throughout the system by having a link to multiple ducts.

Backdraft Dampers

Technicians place backdraft dampers in particular ductwork locations to control airflow in only one direction.

In these dampers, you have to insert shafts on the end of each blade and make the damper blade into a flap that opens once the air flows in the right direction.

When the air starts to flow, or no air passes through in the opposite direction, the blades of this type of damper will automatically close.

Install a counterweight on backdraft dampers to stop or help the opening operation. It is also notable that these diapers don’t include actuators.

Industrial Dampers

Industrial dampers have a design intended to ensure constant temperatures of above 250℉ and high air pressures. They also feature thick gauge materials such as steel to withstand extreme weather conditions.

The components of these dampers are welded in place perfectly to make sure that they last for a long time. Usually, you can see these dampers on power plant industries and other sites that require high amounts of airflows.

Things To Do To Adjust Your HVAC Dampers

Find Your HVAC Damper

You won’t be able to move on to the next steps of adjusting your HVAC dampers if you don’t have any clue where to find them.

For example, in newer homes, you can’t find balancing dampers connected to the ductwork, which in our opinion, is an ineffective way to cut costs.

Meanwhile, you can find the dampers covered up by drywall in other homes due to past remodeling projects. It is also true for homes with basements that were transformed into a rec room or guest room.

On the other hand, some contractors use false vents to give homeowners easy access to damper handles. Try to check all the ceiling vents in your basement if the vent in there happens to be an access panel.

Buildings that utilize premium systems might come with electronic dampers that are automatically controlled by HVACs, providing zone-controlled airflow.

But, if you have this type of system, you won’t need to read the rest of this guide as things are handled by the system automatically.

For those who are not sure whether or not their home utilizes a premium system, you can quickly tell if your dampers have little motors attached with wires instead of physical handles.

Locating HVAC dampers is simple. You only need to check the main duct trunks in your furnace, either in the crawl space, utility room, basement, etc., that are radiating off the furnace. Usually, dampers are within 2-6 feet of the main trunk.

Labeling Your Dampers

Assuming that you are done with the first step, you are now ready for a more rigorous task. First, you need to determine what damper goes where so try to ask someone to help out.

Having an extra hand from your spouse, friend, or family member will allow you to save a lot of time trying to know where a duct leads to. So, before you start, make sure to have a grease pencil or permanent marker ready with you.

Labeling your dampers is not something you will often do. So, be patient and write the labels correctly to make your life easier in the years to come.

Here are the steps to labeling your dampers:

  1. Open all the vents or registers throughout your house. As you are testing every duct, you want maximum airflow to not miss out on anything.

  2. Return to the dampers. To start, select one damper and follow the duct where it is attached as far as you can before it passes through a wall, floor, or is otherwise obscured.

    Doing so will allow you to know where the duct goes. If you are with an assistant, ask them to go to the part of the house where you think the duct goes.

  3. Switch on the blower of the furnace by using the thermostat to activate the fan mode. For those who do not have a fan mode, you may also run the AC or heat.

  4. Close the damper one at a time.

  5. If you have an assistant, ask your assistant to check the ducts in the house area or return to the area to check them. One vent or more in the area has to be still with little to no airflow.

  6. Validate if the damper you are checking is yielding the result you want. You can do so by opening it once and closing it again to make sure.

  7. Now, go back to the damper and label the duct clearly using the marker with “Kitchen,” “Foyer,” or “Living Room.” Again, do not use abbreviations or words that you only understand for the sake of future homeowners.

  8. Lastly, label the dampers for a Winter or Summer position.

Tips When Adjusting The HVAC Dampers

After labeling which dampers affect specific parts of your home, now is the time to know how to make proper adjustments.

This post aims to guide you on the right way to adjust your dampers during summer, so don’t forget to take note of how to label dampers for the summer position.

Hot air tends to rise while cold air sinks. For this reason, your home’s attic is the hottest area of the house while it is coldest in the basement.

Therefore, you need to close the dampers going to the lower parts of your abode. Unfortunately, many airflows will be directed in the upper levels, which will soon cool the lower areas.

For homeowners who are doing this for the first time, it may require a couple of days to know if the adjustments you did are providing the effects you expect.

Since it usually requires a few days to feel the right temperature, it is better not to change the dampers right away. Also, check the rooms you wish to cool to achieve the temperature you want from time to time.

Still, Have Hot Spots Or Cold Spots After Adjusting Dampers?

Let us be honest, dampers are excellent devices, but they don’t guarantee to end cold or hot spots in your home. If you are still experiencing issues in your air balance at home, here are the possible reasons why:

  1. Blocked Air Vents – Ensure that no personal items or furniture block the vents where cold or hot spots are experienced.
  2. Poor Air Flow – Check if your HVAC filters are changed as dirty air filters tend to block airflow.
  3. Air Leaks In Your Ductwork – Unsealed parts of the ductwork can leak a lot of air. If this is the reason why your air balance fails, consider duct sealing to fix hot spots in your abode.


To conclude, having an imbalanced airflow at home can bring significant discomfort to dwellers. The same is true for busy environments like offices and industrial establishments.

Aside from that, it also affects the quality of life in homes. It can also and impacts the overall efficiency of your system.

But other than closing specific dampers in summer, you can also eliminate hot spots in your home by keeping your ductworks clean and free from blockage.

Dirty ducts can hinder healthy airflow in your home as debris and dirt accumulate on duts over time. Unfortunately, most homeowners are not aware that keeping their ductworks well maintained is also the key to having better air balance at home.

For this reason, most people blame everything on the wrong usage of dampers instead of checking and troubleshooting other factors like blocked, dirty ductworks.

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