Put a Damper on the Situation: How (And Why) to Adjust Your HVAC Damper

by Team eLocal
zoned electronic HVAC damper

Every home seems to have warm and cool spots. You might find that no matter what you do, you always need extra blankets in the bedroom or need to remove layers in the den.

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If your home has an HVAC damper system, you may have been able to address this problem without even realizing it.

What Are HVAC Dampers?

A furnace damper is designed to control airflow through individual ducts within your home. If one of your rooms is too hot in the winter, for example, you can reduce the flow of hot air to that area of your home. You can also increase airflow to the rooms that are too cold if you use the HVAC duct damper that corresponds to the room you’re trying to heat up.

Not every home has air dampers because some premium HVAC systems include an automatic damper system that’s designed to keep every area of your home as close to the same temperature as possible. In other instances, the contractors who built your home might have cut corners and left air dampers out of your home construction. If either of these is the case for you, there isn’t much you can do about it.

To see whether your home came with dampers, you can head to your furnace room and look at your air ducts. There are main ducts that go to specific parts of your home, such as upstairs, downstairs and basement levels. If you notice metal levers on your main ducts, you have dampers in your home.

How Do I Use a Damper for HVAC Systems?

Each zone damper controls airflow to a different area of your home, so the first step is to determine where your air ducts go from your main unit. You can do this by following these steps:

Turn the Fan On

If you can’t set your system to run the fan only, that’s okay. Just run your heat or air conditioning instead. After you turn the fan on, you need to open every damper, so the airflow is maximized to every part of your home.

Remove All Your Registers

Registers are the grates that cover your vents in each room. They can also be adjusted to limit airflow, but they don’t do much to change each room’s temperature. Removing them completely opens your home’s ducts, so you can easily determine how changes to your dampers affect individual rooms.

Close Dampers One at a Time

After you close a damper, you can move through your home and find out which rooms don’t have air blowing through the ducts. This will help you determine which dampers control the airflow to which areas of your home.

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Adjust the Dampers

During the winter, you want the dampers to be more open to rooms where you want to direct the most heat. Keep this in mind when making adjustments. If one of the rooms in your home is too hot, closing the damper can cool it down.

Reassess Later

It can take some time for your home to adjust to the changes. Check how each room feels in a day or two and decide whether you want to make any changes. It’s also important to make minor changes first to avoid suddenly having a freezing room or one that’s sweltering.

Mark Where You’ve Chosen to Keep Your Dampers

It’s a good idea to mark the positions you’ve adjusted the dampers to, since you may want to adjust them again when the weather warms up. In general, the most efficient way to direct heat through your home in the winter is to focus on your bottom level and let the heat rise through the rest of your house. These thermodynamics change during the spring, so you may need to change your damper to keep your home cool throughout the summer.

What to Do if Adjusting the Dampers Doesn’t Work

If you’re still having issues with proper heat distribution throughout your house, you may need to have your furnace inspected or repaired. The reason hot air isn’t reaching those colder rooms could be due to a broken component, a blockage in your ducts or another problem that a professional can locate easier than you can.

Things you can do to improve the efficiency of your HVAC system include checking your filters, cleaning your ducts and inspecting your furnace and air conditioning unit at least once a year. The best times to perform preventative HVAC maintenance are in the spring and fall, before the system is stressed by excessive heat or cold.


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